Reading Time: 10 minutes


Nano means one billionth that means 10^-9 times in scientific notation. Have you ever thought how small it is? Avg human height is around 1.5-2m, size of ants are about 2mm, the diameter of a human hair is around 100mm and size of our DNA is around 2nm that means it is 10^-9 times smaller than average human height. To imagine how small is one-billionth let’s go on the other side and see how big an object would be if we are one billionth time larger than the humans. The diameter of the sun is about one billionth times larger than a human. That’s pretty big. So our DNA is as small as humans as humans are from the sun.

What are nanomaterials?? What is its importance? Where are they used? Let’s dive into the world of smallness!!!

Nanomaterials include a broad class of materials, which has at least one dimension less than 100nm. Depending on their shape, they can be 0-D, 1-D, 2-D or 3-D. You may be thinking what this small piece of material can do?? Nanomaterials have an extensive range of applications. The importance of these materials was realized when it was found that size can influence the physicochemical properties of a substance. Nanoparticles have biomedical, environmental, agricultural and industrial based applications.

Nanoparticles are composed of 3 layers-

  • The Surface Layer- It may be functionalized with a variety of small molecules, metal ions, surfactants and polymers.

  • The Shell Layer- It is a chemically different material from the core in all aspects.

  • The Core- It is the central portion of the nanoparticle and usually referred to as nanoparticle itself.

These materials got immense interest from researchers in multidisciplinary fields due to their exceptional characteristics.


Based on the physical and chemical characteristics, some of the well-known classes of NPs are-


  • FULLERENES- It contains nanomaterials that are made up of globular hollow cage such as allotropic forms of carbon. They have properties like electrical conductivity, high strength, structure, electron affinity and versatility. They possess pentagonal and hexagonal carbon units, while each carbon is sp2 hybridized. The structure of C-60 is called Buckminsterfullerene

  • CARBON NANOTUBES(CNTs)- They have elongated, tubular structure, 1-2nm in diameter. They structurally resemble graphite sheets rolling upon itself, which can have single double and many walls and therefore are named as single-walled (SWNTs), double-walled (DWNTs) and multi-walled carbon nanotubes (MWNTs) respectively. They are widely synthesized by decomposition of carbon, especially atomic carbons, vaporized from graphite by laser or by an electric arc to metal particles. Chemical Vapour Deposition (CVD) technique is also used to synthesize CNTs. They can be used as fillers, efficient gas absorbents and as a support medium for different inorganic and organic catalysts.


  1. METAL NPs

They are purely made up of metal precursors. Due to Localized Surface Plasmon Resonance (LSPR) characteristic, they possess unique optoelectrical properties. Due to excellent optical properties, they find their application in various research areas. For example, gold nanoparticles are used to coat the sample before analyzing in SEM.


They are inorganic, nonmetallic solids, synthesized via heat and continuous cooling. They are made up of oxides, carbides, carbonates and phosphates. They can be found in amorphous, polycrystalline, dense, porous or hollow forms. They found their application in catalysis, photocatalysis, photodegradation of dyes and imaging application.


They possess wide band gaps and therefore show significant alteration in their properties with bandgap tuning. They are used in photocatalysis, photo optics and electronic devices. Some of the examples of semiconductor NPs are GaN, GaP, InP, InAs.


They are organic-based NPs, mostly nanospheres and nanocapsules in shape. They are readily functionalized and therefore have a wide range of applications.

  1. LIPID NPs

They contain liquid moieties and are effectively used in many biomedical applications. They are generally spheres with diameters ranging from 10 to 1000nm. They have a solid core made of lipid, and a matrix contains soluble lipophilic molecules.


There are various methods used for the synthesis of NPs, which are broadly classified into two main classes-


Top-down routes are included in the typical solid-state processing of the materials. It is based on bulk materials and makes it smaller, thus using physical processes like crushing, milling and grinding to break large particles. It is a destructive approach, and it is not suitable for preparing uniformly shaped materials. The biggest drawback in this approach is the imperfections of the surface structure, which has a significant impact on physical properties and surface chemistry of nanoparticles. Examples of this approach include grinding/milling, CVD, PVD and other decomposition techniques.



As the name suggests, it refers to the build-up of materials from the bottom: atom by atom, molecule by molecule or cluster by cluster. They are more often used for preparing most of the nanoscale materials which have the ability to generate uniform size, shape and distribution. It effectively covers chemical synthesis and precisely controls the reaction to inhibit further particle growth. Examples are sedimentation and reduction techniques. It includes sol-gel, green synthesis, spinning and biochemical synthesis.


Analysis of different physicochemical properties of NPs is done using various characterization techniques. It includes techniques such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Infrared (IR), SEM, TEM and particle size analysis.


Morphology always influences most of the properties of the NPs. Microscopic techniques are used for characterization for morphological studies such as a polarized optical microscope, SEM and TEM.

SEM technique is based on electron scanning principle. It uses a focused beam of high energy electrons to generate a variety of signals at the surface of solid specimens. It is not only used to study the morphology of nanomaterials, but also the dispersion of NPs in the bulk or matrix.

TEM is based on electron transmission principle so that it can provide information on bulk material from very low to higher magnification. In TEM a high energy beam of electrons is shone through a skinny sample. This technique is used to study different morphologies of gold NPs. It also provides essential information about two or more layer materials.



Structural characteristics are of primary importance to study the composition and nature of bonding materials. It provides diverse information about the bulk properties of the subject material. XRD, Energy dispersive X-ray (EDX), XPS, IR, Raman and BET are the techniques used to study the structural properties of NPs.

XRD is one of the most used characterization techniques to disclose the structural properties of NPs. Crystallinity and phases of nanoparticles can be determined using this technique. Particle size can also be determined by using this technique. It worked well in identification of both single and multiphase NPs.

EDX is usually fixed with field emission-SEM or TEM device is widely used to know about the elemental composition with a rough idea of per cent weight. Nanoparticles comprise constituent elements, and each of them emits characteristic energy X-rays by electron beam eradication.

XPS is one of the most sensitive techniques used to determine the exact elemental ratio and exact bonding nature of elements in nanoparticles materials. It is a surface-sensitive technique used in-depth profiling studies to know the overall composition and the compositional variation with depth.


Size of the particle can be estimated by using SEM, TEM, XRD and dynamic light scattering (DLS). Zeta potential size analyzer/DLS can be used to find the size of NPs at a deficient level.

NTA is another new and exclusive technique which allows us to find the size distribution profile of NPs with a diameter ranging from 10 to 1000nm in a liquid medium. By using this technique, we can visualize and analyze the NPs in a liquid medium that relates the Brownian motion rate to particle size. It can be helpful in biological systems such as protein and DNA.

NPs have large surface areas, so it offers excellent room for various applications. BET is the most used technique to determine the surface area of nanoparticles material. Principle of this technique is adsorption and desorption and Brunauer-Emmett-Teller (BET) theorem.


Optical properties are of great concern in photocatalytic applications. These characterizations are based on Beer-lambert law and basic light principles. The techniques used to give information about absorption, luminescence and phosphorescence properties of NPs. The optical properties of NPs materials can be studied by well-known equipment like Ultraviolet-visible, photoluminescence and the ellipsometer.


So it’s all about the size, isn’t it? Yes and no. When a material becomes a nanomaterial is not so simple. A nanomaterial may have different properties compared to the same substance in bulk form. That means that a material could change when it goes from bulk to nanoform, but at what size that happens varies depending on the substance.Nanoparticles are used in various applications due to their unique properties such as large surface area, strength, optically active and chemically reactive.


The optical and electronic properties of nanoparticles are dependent on each other. For example, gold colloidal nanoparticles are the reason for the rusty colours seen in blemished glass windows, while Ag NPs are typically yellow. The free electrons on the surface of nanomaterials are free to move across the material. The mean free path of Ag and gold is ~50nm, which is greater than the NPs size of these materials. Therefore, no scattering is expected from the bulk, when light interacts. Instead, they set into a standing resonance condition, which is responsible for LSPR in the NPs.


There is a class of nanoparticles known as magnetic nanoparticles that can be manipulated using magnetic fields. Such particles consist of two components- a magnetic material and chemical component that has functionality. These types of materials have a wide range of applications which includes heterogeneous and homogeneous catalysis, biomedicine, magnetic fluids, MRI and also in water decontamination. Magnetic properties of NPs dominate when its size is less than the critical value, i.e. 10-20nm. The reason for these magnetic properties is the uneven electronic distribution in NPs.


To know the exact mechanical nature of NPs different mechanical parameters such as elastic modulus, hardness, stress and strain, adhesion and friction are surveyed. Due to distant mechanical properties of NPs, it finds its application in fields like tribology, surface engineering, nanofabrication and nanomanufacturing. NPs shows different mechanical properties as compared to microparticles and their bulk materials.


It is well known that metals have better thermal conductivities than that of fluids. Same is the case of NPs. Thermal conductivity of copper is much higher than water and engine oil. Thermal conductivity of fluids can be increased by dispersing solid particles in them. Using the same way nanofluids are produced which have nanometric scales solid particles dispersed into a liquid such as water, ethylene glycol or oils. They are expected to exhibit superior properties relative to those of conventional heat transfer fluids and fluids containing microscopic solid particles. As heat transfer takes place at the surface of the particles, it is better to use the particles with large surface area, and it also increases the stability suspension.


As discussed above the nanoparticles have various unique properties. Due to their properties, they find their applications in multiple fields, including drugs, medication, manufacturing, electronics, multiple industries and also in the environment.


Nano-sized inorganic particles have unique, physical and chemical properties. They are an essential material in the development of various nanodevices which can be used in multiple physical, biological, biomedical and pharmaceutical applications. Particles of an iron oxide such as magnetite (Fe3O4) or its oxides from maghemite (Fe2O3) are used in biomedical applications. Polyethene oxide (PEO) and polylactic acid (PLA) NPs have been revealed as up-and-coming systems for the intravenous administration of drugs. Biomedical applications require NPs with high magnetization value, a size smaller than 100nm and a narrow particle size distribution. Most of the semiconductor and metal NPs have immense potential cancer diagnosis and therapy.

Image shows the bamboo-like structure of nitrogen-doped carbon nanotubes for the treatment of cancer.


In specific applications within the medical, commercial and ecological sectors manufacturing NPs are used which show physicochemical characteristics that induce unique electrical, mechanical, optical and imaging properties. Nanotechnology is used in various industries, including food processing and packaging. The unique plasmon absorbance features of the noble metals NPs have been used for a wide variety of applications including chemical sensors and biosensors.

Nanomaterials are also used in some environmental applications like green chemistry, pollution prevention, the recommendation of contaminated materials and sensors for ecological stages.

NPs such as metallic NPs, organic electronic molecules, CNTs and ceramic NPs are expected to flow as a mass production process for new types of electronic equipment.

NPs can also offer applications in mechanical industries, especially in coating, lubricants and adhesive applications. Its mechanical strength can be used to produce mechanically more reliable nanodevices.


Nanomaterials are no doubt the future of technology, being the smallest material they have a wide range of applications due to their unique physical and chemical properties. Due to their small size, NPs have a large surface area which also makes them suitable candidates for many applications. Even at that size, optical properties dominate, which further increase their importance in photocatalytic applications. Though NPs are used for various applications, still they have some health hazard concerns due to their uncontrollable use and discharge to the natural environment, which should be considered to make the use of NPs more convenient and environmentally friendly.


Keep Learning!, Keep Growing!

Team CEV


Reading Time: 5 minutes

Team CEV has conducted a three-day event where top professors of SVNIT shared their excellent research work with enthusiastic students. Professors have given some time from their precious and hectic time schedule for our event. The main purpose of the event is to give students an insight into various fields of research and help them find their field of interest to work on and also to give knowledge of different professors that can’t be shared in the classroom due to academic schedules.

LUMIERES - WISDOM WEEKThe event has been inaugurated by Dr.Jignesh N. Sarvaiya, Associate Professor – Electronics departments, who also gave the first talk of the event. The topic of the talk was “Image Processing”. Dr Sarvaiya gave some excellent insight into the whole back story of an Image. And also explained how are images captured and what exactly are pixels. Some insights into the algebra involved behind the processing of an image.

LUMIERES - WISDOM WEEKThe next talk was given by Dr A. K. Desai, Professor – Applied Mechanics Department. His topic was “Recent Advances in Structural and Geotechnical Technologies”. Dr. Desai showed us the importance of structural engineering in solving the many present problems of traffic in more economic and less inconvenience to the public. Also, the talk covered the contribution of structural engineering in the recent development of buildings, bridges and flyovers and many more.


The final talk of the 1st day was given by Dr Shriniwas Arkatkar, Associate Professor – Civil Engineering Department. The topic of the talk was “A look at transport of the future in developing countries”. The talk basically covered the present transport problems and some possible solutions to these problems in the future. Dr. Arkatkar stressed much on interdisciplinary projects in developing more standard solutions and he strongly believes that these problems can not be solved by any single engineering department.  



The kick start to the 2nd day of Lumieres- Wisdom Week was given by Dr. Chetan Patel, Associate Professor- Chemical Engineering Department. The topic of the talk was “Nanoparticles”. Dr Patel explained the methods of preparation of nanoparticles and also challenges faced in the same. The importance of nanoparticles and how materials behave in the size of nanoparticles varies from its normal known particles and also how the nanoparticles are contributing in different fields of development are discussed.

LUMIERES - WISDOM WEEK The next talk was given by Dr P.V. Bhale, Assistant Professor – Mechanical Engineering department. The topic of the talk was ”Renewable Energies and Industries”.  In the recent times of very high rate of depletion of fossil fuels, a high number of researches are being carried out to develop an alternative fuel, most probably from renewable sources with the intention to don’t harm the environment. Dr Bhale explained different potentials of available renewable sources and challenges faced to make it a primary source of energy and economically easy to produce energy from such fuels.

LUMIERES - WISDOM WEEKThe final talk of the 2nd day was given by Dr Vipul Kheraj, Associate Professor – Applied Physics Department. The topic of the talk is” Light – A Fascinating Probe to the Universe”. Dr Vipul has explained what and how fascinating things can be proved by using light, like short bending of space time graph due to massive celestial bodies. The concept behind G.P.S. The LIGOs which were built to determine the passage of Gravitational waves, LIGO is basically a massive interferometer built in 4km X 4km radius.

LUMIERES - WISDOM WEEKThe last day of the LUMIERES- Wisdom Week was started by Dr. Jayesh Dhodiya, Associate Professor – Applied Mathematics and Humanities Department.The topic of the talk was “Application of Mathematical Modelling in Engineering Problems “. Dr Dhodiya has excellently explained how to see an engineering problem and how to approach the solution of the problem. The talk gave an idea of the importance of Mathematical Modelling to solve any real-life problems, without which it will be more difficult to find out the best possible solution to the problem.

LUMIERES - WISDOM WEEK The last talk of the LUMIERES – Wisdom Week was given by Dr A.K. Panchal, Professor- Electrical Engineering Department. The topic of the talk was “Solar Cells and Renewable Energy”. Dr Panchal provided all the statistics regarding usage of fuels and need of renewable energy to come into picture predominantly. Also he explained why it is still difficult to bring renewable energy in large scale, economic factors and efficiency factors and many other factors which play a dominant role in these pictures. The talk also gave an idea about the making of solar cells, materials needed, factors to be considered and many more.

LUMIERES - WISDOM WEEKWith this series of talks, LUMIERES – Wisdom Week 1.0 has been concluded. Team CEV is pretty much sure that everyone got so much to learn from the professors and also got to know the professors.



Why do Rockets love to fail?

Reading Time: 8 minutes

Deepak Kumar
Propulsion Engineer, Dept. of Propulsion, STAR

“Rockets, they really don’t wanna work, they like to blow up a lot”


         – Elon Musk

If you take look at all the List of spaceflight-related accidents and incidents – Wikipedia , you’ll realize there have been countless failures. That the answer to “How many”.


Rockets can fail anytime. Moreover, a rocket isn’t a simple machine at all. A massive structure having around 2.5 billion dynamic parts is likely to fail anytime if any of these parts says, “ I can’t do this anymore, I’m done”.


Coming to some of the well known Rocket Failures, this will help you learn how rockets fail!


1. The Space Shuttle Challenger Disaster

Why do Rockets love to fail?

The spaceflight of Space Shuttle carried a crew of 7 members, when it disintegrated over the Atlantic Ocean. The disintegration was caused due to the failure of one of Solid Rocket Boosters(SRB). The SRB failed during the lift-off.


The failure of SRB was caused due to O-Rings. O-ring is mechanical gasket that is used to create a seal at the interface. And here, that interface was between two fuel segments. O-Ring was designed to avoid the escaping of gases produced due to burning of solid fuel. But extreme cold weather on the morning of launch date, the O-Ring became stiff and it failed to seal the interface.

Why do Rockets love to fail?

This malfunctioning caused a breach at the interface. The escaping gases impinged upon the adjacent SRB aft field joint hardware( hardware joining the SRB to the main structure) and the fuel tank. This led to the separation of the Right Hand SRB’s aft field joint attachment and the structural failure of external tank.

Why do Rockets love to fail?

In the video below, the speaker mentions about the weather being chilly on that morning and icicles formed on the launch pad in the morning. One of SRB is clearly visible making its own way after the failure.

2. The Space Shuttle Columbia Disaster

Unlike the above failure, this failure occurred during the re-entry. But again, the story traces back to the launch. During the launch, a piece of foam broke off from the external fuel tank and struck the left wing of the orbiter.

Why do Rockets love to fail?

This is an image of orbiter’s left wing after being struck by the foam. The foam actually broke off from the bi-pod ramp that connects the orbiter and fuel tank.

Why do Rockets love to fail?

The foam hit the wing at nearly a speed of 877 km/h causing damage to the heat shield below the orbiter. The piece of foam that broke off the external fuel tank was nearly the size of a suitcase and could have likely created a hole of 15–25 cms in diameter.

Why do Rockets love to fail?

The black portion below the nose you see is the carbon heat shield of orbiter.

On Feb 1,2003 during the re-entry, at an altitude of nearly 70 km, temperature of wing edge reached 1650 °C and the hot gases penetrated the wing of orbiter. Immense heat energy caused a lot of dange. At an altitude of nearly 60 km, the sensors started to fail, the radio contact was lost, Columbia was gone out of control and the left wing of the orbiter broke. The crew cabin broke and the vehicle disintegrated.



You can clearly see the vehicle disintegrating. **The video is a big one, hang tight. 😉


3. The N1 Rocket Failure

Not many people know about this programme. It was started in 1969 by the Russians. N1 rocket remains the largest rocket ever built till date. The rocket had its last launch in 1972. During this tenure, the were four launches, all of them failed. Yes you heard it right, ALL OF THEM FAILED.

Why do Rockets love to fail?

Before discussing the failures, there is one thing that I never forget to mention about this rocket. Rockets rely on TVC(Thrust Vector Control) to change the direction of the thrust. The nozzle direction is changed to alter the direction of thrust.

Why do Rockets love to fail?

This is TVC. But in case of N1 Rocket, there was something called Static Thrust Vectoring. There were 30 engines in stage 1, 8 engines in stage 2, 4 engines in stage 3 and 1 in stage 4.

Why do Rockets love to fail?

There were 24 on the outer perimeter and the remaining 6 around the centre.

In order to change the direction of rocket, the thrust was changed in the engines accordingly. The engines didn’t move like TVC at all.

Now coming to the failed launches:

Launch 1:

The engines were monitored by KORD(Control of Rocket Engines). During the initial phase of flight, a transient voltage caused KORD to shut down the engine #12. Simultaneously, engine #24 was shut down to maintain stability of the rocket. At T+6 seconds, pogo oscillation( a type of combustion instability that causes damage to the engine) in the #2 engine tore several components off their mounts and started a propellant leak. At T+25 seconds, further vibrations ruptured a fuel line and caused RP-1 to spill into the aft section of the booster. When it came into contact with the leaking gas, a fire started. The fire then burned through wiring in the power supply, causing electrical arcing which was picked up by sensors and interpreted by the KORD as a pressurization problem in the turbopumps.

Launch 2:

Launch took place at 11:18 PM Moscow time. For a few moments, the rocket lifted into the night sky. As soon as it cleared the tower, there was a flash of light, and debris could be seen falling from the bottom of the first stage. All the engines instantly shut down except engine #18. This caused the N-1 to lean over at a 45-degree angle and drop back onto launch pad 110 East. Nearly 2300 tons of propellant on board triggered a massive blast and shock wave that shattered windows across the launch complex and sent debris flying as far as 6 miles (10 kilometers) from the center of the explosion. Just before liftoff, the LOX turbopump in the #8 engine exploded (the pump was recovered from the debris and found to have signs of fire and melting), the shock wave severing surrounding propellant lines and starting a fire from leaking fuel. The fire damaged various components in the thrust section leading to the engines gradually being shut down between T+10 and T+12 seconds. The KORD had shut off engines #7, #19, #20, and #21 after detecting abnormal pressure and pump speeds. Telemetry did not provide any explanation as to what shut off the other engines. This was one of the largest artificial non-nuclear explosions in human history.

Launch 3:

Soon after lift-off, due to unexpected eddy and counter-currents at the base of Block A (the first stage), the N-1 experienced an uncontrolled roll beyond the capability of the control system to compensate. The KORD computer sensed an abnormal situation and sent a shutdown command to the first stage, but as noted above, the guidance program had since been modified to prevent this from happening until 50 seconds into launch. The roll, which had initially been 6° per second, began rapidly accelerating. At T+39 seconds, the booster was rolling at nearly 40° per second, causing the inertial guidance system to go into gimbal lock and at T+48 seconds, the vehicle disintegrated from structural loads. The interstage truss between the second and third stages twisted apart and the latter separated from the stack and at T+50 seconds, the cutoff command to the first stage was unblocked and the engines immediately shut down. The upper stages impacted about 4 miles (7 kilometers) from the launch complex. Despite the engine shutoff, the first and second stages still had enough momentum to travel for some distance before falling to earth about 9 miles (15 kilometers) from the launch complex and blasting a 15-meter-deep (50-foot) crater in the steppe.


Launch 4:

The start and lift-off went well. At T+90 seconds, a programmed shutdown of the core propulsion system (the six center engines) was performed to reduce the structural stress on the booster. Because of excessive dynamic loads caused by a hydraulic shock wave when the six engines were shut down abruptly, lines for feeding fuel and oxidizer to the core propulsion system burst and a fire started in the boat-tail of the booster; in addition, the #4 engine exploded. The first stage broke up starting at T+107 seconds and all telemetry data ceased at T+110 seconds.

Besides the mechanical failures, the rockets might fail due to a minute discrepancy in program’s as in case of Ariane 5.

Ariane 5: After 37 seconds later, the rocket flipped 90 degrees in the wrong direction, and less than two seconds later, aerodynamic forces ripped the boosters apart from the main stage at a height of 4km. This caused the self-destruct mechanism to trigger, and the spacecraft was consumed in a gigantic fireball of liquid hydrogen.

The fault was quickly identified as a software bug in the rocket’s Inertial Reference System. The rocket used this system to determine whether it was pointing up or down, which is formally known as the horizontal bias, or informally as a BH value. This value was represented by a 64-bit floating variable, which was perfectly adequate.

However, problems began to occur when the software attempted to stuff this 64-bit variable, which can represent billions of potential values, into a 16-bit integer, which can only represent 65,535 potential values. For the first few seconds of flight, the rocket’s acceleration was low, so the conversion between these two values was successful. However, as the rocket’s velocity increased, the 64-bit variable exceeded 65k, and became too large to fit in a 16-bit variable. It was at this point that the processor encountered an operand error, and populated the BH variable with a diagnostic value.

That’s your answer to “why”. Rockets can fail anytime due even a small malfunction in one of those 2.5 billion dynamic parts or even a small programming error.

Hope you enjoyed the writings up there!

Thank You!

Source: Google and Wikipedia



Looking forward to excel in rocket building?

Check out this link Space Technology and Aeronautical Rocketry- STAR

Future Coating Technologies : A REVIEW PAPER

Reading Time: 18 minutes

Author: Sanidhya Somani, ECE, 2nd Year


For decades we have been hearing that the chemical industry and there also the coating industry, need to break free from its dependency on oil because there are finite resources. Renewable raw materials are constantly under discussion. The paint and coatings industry is focused on innovation and being “green”. Green means a smaller carbon footprint, low VOC content, high renewable content and green processes. The use of renewable ingredients to reduce the carbon footprint, eliminating the use of hazardous materials, introducing bio renewables, incorporating recycled materials, lowering VOC emissions, decreasing energy consumption and reducing waste, while proving it can all be accomplished cost-effectively to become more environmentally responsible. The reduction of environmental damage done by coatings sometimes begins before manufacturing even starts. Research into the carbon footprint of coating materials, or the overall amount of climate-affecting carbon dioxide produced in their manufacture, application, transport and disposal, shows that some coatings simply use fewer resources throughout their life cycles. This paper discusses advances in the use of renewable resources in formulations for various types of coatings. The developments in the application of (new) vegetable oils and plant proteins in coating systems are discussed here.


As the climate continues to change, human population continues to grow, and our natural resources continue to diminish, industries have seen a global shift, placing greater importance on green design and sustainable business practices. However, green design is less about following a popular trend than it is about simply respecting our limited natural resources. The architectural coating industry is no exception to this trend, as building and construction regulations continue to evolve and incorporate higher standards for environmentally friendly practices.

Suppliers to the coating industry offer an increasing range of bio-based raw materials. For instance, a green hardener with a high carbon content from renewable resources. Raw materials from renewable resources was one of the trends. Manufacturers are working harder than ever to develop high-performance coatings that lessen the negative impact on the environment. To do this, coating developers created innovative manufacturing techniques that protect air and water quality while reducing the unnecessary consumption of natural resources. They focus on eliminating the use of hazardous materials, introducing bio-renewables, incorporating recycled materials, lowering VOC emissions, decreasing energy consumption and reducing waste, while proving it can all be accomplished cost-effectively.

However, in the past few years consumer’s and industrial interest in environmentally friendlier paints and coatings has been growing tremendously. This trend has been spurred not only by the realization that the supply of fossil resources is inherently finite, but also by a growing concern for environmental issues, such as volatile organic solvent emissions and recycling or waste disposal problems at the end of a resin’s economic lifetime. Furthermore, developments in organic chemistry and fundamental knowledge on the physics and chemistry of paints and coatings enabled some problems encountered before in vegetable oil-based products to be solved. This resulted in the development of coatings formulations with much-improved performance that are based on renewable resources.

A Look-Back

Coating manufacturers around the world worked tirelessly to create paints that eliminated adverse environmental implications and pushed the industry towards a more sustainable future. Volatile Organic Compounds (VOCs) have long been part of the coating industry as their properties have aided in the application of coatings. Recognized as a component of the common aroma of paint fumes, VOCs are believed to contribute to the formation of ground-level ozone and urban smog, which in turn, may contribute to adverse health effects. After truly understanding the effects of VOCs, coating manufacturers directed their focus to creating formulations that lessen the need to use solvents. It was able to achieve this by using a higher percentage of solids in its formulations that resulted in less coating volatizing into the air.
The next step is to look at the coating process. Even the way coil coatings are applied to the metal used for wall and roofing panels has been enhanced for better environmental performance.  Coil coating— where the paint is rolled onto the metal in a factory setting— is a pretty energy efficient technique. When coil coating metal panelling, the VOC gases that are released during the process are returned to the system, and through the use of a thermal oxidizer (also known as a thermal incinerator), become fuel for the curing process.

A view on Low VOC coatings

VOC is a general term referring to any organic substance with an initial boiling point less than or equal to 250 degrees Centigrade (European Union definition) that can be released from the paint into the air, and thus may cause atmospheric pollution. VOCs are volatile organic compounds that can be naturally occurring (such as ethanol) or can be synthesised chemically. The VOC content in water-based paints may be a very small amount of solvent or trace levels of additive in the paint that are needed to enhance its performance. Paint is made up of a number of components. Some of these may be of natural origin (such as minerals, chalk, clays or natural oils), other components (such as binders, pigments and additives) are more often synthetically-derived from different industrial chemical processes. All these components need to undergo some degree of washing, refinement, processing or chemical treatment, so they can be successfully used to make paint. These production steps necessitate the use of different process aids, including substances that are classed as VOCs. Although every effort is made to remove these VOCs through drying and purifying, there will still be trace amounts in the finished raw materials that are used to make the paint and the tinting pastes that are needed to be used. Therefore, there is no such thing as a truly 100% VOC-free or Zero VOC paint, as all paints will contain very small (trace) amounts of VOCs through their raw materials. There are several key contributors to the environmental footprint of household paint – the extraction/production of the raw materials, the cost of transporting paint from factory to retail outlet to your home, and how long the painted surface will last until it needs repainting i.e. how durable the paint film is. This last aspect is of particular interest – a durable longer-lasting paint is better for the environment. Many paints which claim ‘Zero VOC / VOC-free’ credentials are based on natural clays and oils rather than synthetic binders such as vinyl or acrylic. This has an impact on how resistant the paint film is to water or to damage – generally, synthetic-binder based paints will provide a much more durable and resistant paint film, so would be expected to last longer than a clay paint. Thus, walls with these clay paints on may need repainting more often, and the clay paints would not score so well, when viewed from an overall environmental footprinting approach. Thus, perversely, ‘Zero VOC’ clay paints may actually be more harmful to the environment than standard synthetic-binder based paints, due to this increased maintenance cycle.

Protein and vegetable oil-based coatings

As an increasing interest is observed in the development of more environment-friendly paints and coatings. In recent, the developments in the application of vegetable oils and plant proteins in coating systems are addressed. Regarding vegetable-oil-based binders, current research is focussed on an increased application of oils from conventional as well as new oilseed crops. A very interesting new vegetable oil, for example, originates from such crops as Euphorbia lagascae and Vernonia galamensis, which have high contents (>60%) of an epoxy fatty acid (9c,12,13 epoxy-octadecenoic acid or vernolic acid) that can be used as a reactive diluent. Another interesting new oil is derived from Calendula officinalis, or “Marigold”. This oil contains >63% of a C18 conjugated tri-ene fatty acid (8t,10t,12c-octadecatrienoic acid or calendic acid), analogous to the major fatty acid in tung oil. Presently, research aims at evaluating film-forming abilities of these oils and of chemical derivatives of these oils, both in solvent-borne and water-based emulsion systems. In research on industrial applications of plant proteins, corn, but particularly wheat gluten has been modified chemically to obtain protein dispersions that have excellent film-forming characteristics and strong adhesion to various surfaces. Especially wheat gluten films have very interesting mechanical properties, such as an extensibility of over 600%. Gas and moisture permeabilities were found to be easily adjustable by changing the exact formulation of the protein dispersion.

Wheat gluten coatings

In developing non-food applications of proteins, various proteins such as soy protein, corn gluten, wheat gluten, and pea proteins are being studied. Based on its unique functional properties, wheat gluten can be distinguished from other industrial proteins. Examples are its insolubility in water, adhesive/cohesive properties, viscoelastic behaviour, film-forming properties and barrier properties for water vapor and gases. Wheat gluten shows, like other amorphous polymers, a glass transition temperature (T,). Below the Tg, gluten films are brittle. To obtain rubbery gluten coatings, the addition of plasticizers is required.

Vegetable oil-based coatings

In the past many seed oils have been applied in various coatings formulations. In the 1950s the most common plant oil in trade sales paint formulations was linseed oil with a share of 50%. Since then not only the total volume of fats and oils used in drying oil products has declined, also the relative position of linseed oil has slowly declined to less than 30% of the plant oil used. Simultaneously the share of soybean oil increased such that now soybean oil is the predominant oil used in this area. The use of soybean fatty acids in ‘soybean-modified’ alkyds is obviously a contributing factor to this.

Water-borne emulsion coatings

The major advantage of water-borne emulsion coatings is the reduction in volatile organic compounds emission upon drying of the film. In the past, research has been focused on the emulsification behaviour of pure linseed oil. The application of waterborne paints to coat wood, metal, plastics or mineral substrates has increased considerably over the last ten years. The share of the market for waterborne coatings varies greatly between countries, as it does between coating market segments. The global coatings market can be categorized broadly into decorative coatings and industrial coatings. Waterborne silicate paints combine high permeability to water vapor and carbon dioxide with a very useful minimal soiling tendency. The term functional paint surface is understood to imply improvements such as the avoidance of algal and fungal growth by the introduction of nanoparticulate silver to replace biocidal compounds and improved soiling resistance and degradation of air pollutants through the use of photocatalytically active nano-titanium. More than 80% of the sealant systems for parquet floors and solid wood flooring are water-based, often using a combination of water-based polyurethane dispersions and self-crosslinking polyacrylate dispersions.

100% Renewable Ethoxylated Surfactants

Bio-based ethylene oxide (EO) will meet this demand by enabling the synthesis of various ethoxylated surfactants and emulsifiers which are 100% bio-based. Ethoxylation is a common process used to generate a range of products for emulsification and wetting, including ethoxylated alcohols, carboxylic acids and esters.  While the hydrophobic portions of many of these surfactants are already naturally sourced from plant oils, only petrochemical-derived EO has been available. With the production of bio-based EO in the near future, ethoxylated products can now be produced from 100% bio-based content, allowing customers to choose fully renewable products without sacrificing performance.  In addition, by incorporation into synthetic base materials, the bio-based content can be significantly increased, allowing formulators to meet challenging new targets. Alkyl polyglucosides are an example of a surfactant class based on renewable raw materials. Other bio-based options include some betaines and proteins, but these are rarely used in the coatings market. Fermentation is used to make some production processes more environmentally friendly and bio-catalysis is also being actively researched. Far more abundantly available and used renewable sources are the natural oils from animal fats or plant seeds. Some of the derivatives of these are oleochemicals. The fatty content from the oils can be separated by distillation into products containing chains of 12 to 18 carbon atoms in saturated or unsaturated form.  For example, lauryl, cetyl, stearyl and oleyl alcohols are commonly available and have appropriate hydrocarbon chain lengths to function as the hydrophobic tail group in surfactants. many renewable ionic surfactants can be made by this route including quaternary ammonium salts, amine oxides, and alcohol sulphates.

Biorenewable sources used during manufacturing of polyurethane (PU) adhesives have been used extensively from last few decades and replaced petrochemical based PU adhesive due to their lower environmental impact, easy availability, low cost and biodegradability. Biorenewable sources, such as vegetable oils (like palm oil, castor oil, jatropha oil, soybean oil), lactic acid, potato starch and other biorenewable sources, constitute a rich source for the synthesis of polyols which are being considered for the production of “eco-friendly” PU adhesives.

Ultraviolet curable coating technology

The advances in ultraviolet (UV)-curing coating technology to develop high performance coating systems that have zero discharge of volatile organic compound (VOC) emissions or hazardous waste generation. Included in the research was the incorporation of certain proprietary, non-toxic, corrosion-inhibiting pigments into the coating formulations. One of several problems is that of the pigments in the UV curing formulations absorbing the UV light and therefore not allowing the UV light to cure the paint. The pigments also increase the viscosity of the paint and make it more brittle than it would be unpigmented. There are low viscosity polymers available to use but they invariably have a low molecular weight which makes for low resistance to chemicals. The higher molecular weight polymers resist chemicals and solvents better but are invariably more brittle. It was an ever-present challenge to balance each coating’s UV curability against its viscosity and brittleness, and its chemical resistance against its brittleness.

Spray booth technology

This has unveiled a scrubbing system, which utilizes a regenerative dry filtration process that separates wet paint overspray from spray booth process air. The process allows significant reductions in paint spray booth energy usage and emissions. Spray booths are the leading energy consumer at most large-volume paint finishing operations. By recirculating a substantial portion of exhausted air from the spray booth back into the painting chamber, the quantity of air that must be fully conditioned is significantly reduced. The dry system operates by directing paint-laden process air into scrubber chambers located directly below and on either side of the painting chamber. Each scrubbing chamber contains an array of porous, plastic filter elements. To protect the filter elements from becoming fouled with tacky paint particles, a process referred to as pre-coating is utilized. The pre-coat process extends the life of the filter elements to a minimum of 15,000 hours.

Replacement of Commercial Silica by Rice Husk Ash in Epoxy Coating

Since epoxy resins are used as composite matrix with excellent results, and silica is one of the fillers most often employed, the rice husk ash (RHA) as filler replace high-purity silica in epoxy composites. RHA and silica exhibited similar mechanical and water absorption characteristics, indicating that rice husk ash may be a suitable replacement for silica. the good filler dispersion and distribution in the polymer matrix, highlighting the more effective adhesion interface between RHA particles and the matrix. RHA behaved similarly to crystalline silica, so it can be used as replacement of silica with little loss of properties. The tensile strength and water absorption values were around the same order of magnitude, though RHA composites exhibited better values in general. SEM analysis showed that filler particles distributed well into the polymer matrix. The adhesion interface between filler particles and polymer matrix was more effective when RHA was used, though some voids associated with porosity of this material were observed. Viscosity values revealed that viscosity of mixtures prepared with RHAs increases exponentially with the proportion of filler added (60%), pointing to the risk of problems in processing operations, depending on the application of composites. In this sense, alternative methods to control and reduce viscosity should be considered when high proportions of RHA are used. Overall, lower amounts of RHA (20% and 40%) produce composites with properties that are comparable to those prepared with commercial silica as filler.

Nanomaterials applications in “green” functional coatings

The global coating market is huge, worth over US$100 billion annually, with applications for physical and chemical protection, decoration and various other functions. In the last decade, the trend is definitely pointing toward the replacement of traditional VOC (volatile organic chemical)-based paints and polluting processes like electroplating with environmentally friendly materials and technologies. Nanomaterials play a significant role in the new generation of “green” functional coatings by providing specific functionalities to the base coating. For the replacement of electroplated metal coatings, a multilayer coating stack providing anticorrosion, mirror-like reflective and antiscratch functions was developed. Nanosized metal and ceramic particles are used to achieve these functions without the use of any polluting chemicals nor the release of any heavy metal contamination typical from electroplating processes. Furthermore, a multifunctional environmental paint was developed for wood surfaces. The key ingredient in this water-based paint is mesoporous silica nanoparticles, which offers high water resistance and a short drying time. This versatile material also offers high chemical tunability, which allows the incorporation of various additives to achieve multiple functions including antibacterial action and resistance to fire, household chemicals and UV (ultraviolet) exposure.

Powder coatings

Coatings such as water-based paints and finishes applied by the powder coating process, in which powdered material is sprayed onto a surface and then baked on to form a tough protective barrier, have lower carbon footprints — and consequently lower environmental impact — than coatings that must be thinned with chemical solvents before they are sprayed or painted onto the surface. Simply choosing a lower-impact alternative like these is an instant way to improve the green-ness of a project or product.

Likewise, advances in powder coating have made these finishes tougher, meaning that the new-generation coatings can be applied in thinner layers than their predecessors. Thus, less material gets used in the process; not only does this reduce the amount of overspray — excess powder that doesn’t adhere to the surface and has to be cleaned up afterward — but it also saves money in situations that involve coating large surfaces, such as the metal sides of shipping containers.

Solar Reflective pigments

When the strong rays of the sun strike the roof and exterior of a building, the absorbed infrared light is converted to heat, which leads to a rise in interior temperature. Within an urban sprawl, this problem compounds with smog, asphalt and a lack of vegetation creating a phenomenon known as the “heat island effect.” This effect can dramatically increase costly air conditioning and electricity expenditures for building owners.

To help mitigate the heat island effect, manufacturers turned to solar reflective pigments that reflect infrared radiation while still absorbing the same amount of visible light.  Through the incorporation of these pigments, manufactures created solar reflective coatings that stay much cooler than their non-reflective counterparts. Solar reflective coatings not only help lower energy costs without sacrificing durability, performance or beauty, but also provide an array of colours options that previously absorbed considerably higher amounts of infrared light.

CNSL: an environment friendly alternative for the modern coating industry

Considering ecological and economical issues in the new generation coating industries, the maximum utilization of naturally occurring materials for polymer synthesis can be an obvious option. In the same line, one of the promising candidates for substituting partially, and to some extent totally, petroleum-based raw materials with an equivalent or even enhanced performance properties, is the Cashew Nut Shell Liquid (CNSL). This dark brown coloured viscous liquid obtained from shells of the cashew nut can be utilized for a number of polymerization reactions due to its reactive phenolic structure and a meta-substituted unsaturated aliphatic chain. Therefore, a wide variety of resins can be synthesized from CNSL, such as polyesters, phenolic resins, epoxy resins, polyurethanes, acrylics, vinyl, alkyds, etc. The present article discusses the potential of CNSL and its derivatives as an environment friendly alternative for petroleum-based raw materials as far as polymer and coating industries are concerned. CNSL, one of the major sustainable resources, mainly extracted by hot-oil and roasting process, contains number of useful phenolic derivatives like cardol, cardanol, 2-methyl cardol, and anacardic acid with meta-substituted unsaturated hydrocarbon chain (chain length of C15). The combination of reactive phenolic structure and unsaturated hydrocarbon chain makes CNSL a suitable starting material to synthesize various resins like epoxy, alkyd, polyurethanes, acrylics, phenolic resins, etc. In addition, a number of other useful products, such as modifiers like flexibilizer and reactive diluents, adhesives, laminating resins, antioxidants, colorants and dyes, etc., have also been developed from CNSL and its derivatives. So, considering the high depletion rate of petroleum-based stocks and the range of possible applications, CNSL can be accepted as a greener and sustainable approach for future expansion in the modern coating industry.


How has the industry managed with all of the uncertainty related to being green? More or less all the leading coatings manufacturers have sustainability manifested in their corporate values and strategies and have implemented teams to steer the process toward more ecological solutions, from sourcing of raw materials to the development of new products and the optimization of manufacturing processes. At the same time, raw material suppliers are mainly focusing on the use of renewable raw materials, products without hazardous labelling, and energy efficiency across the value chain.

Impact of additives in green coating

Additives have a significant impact on performance and functionality, although they represent only a small fraction of the total content of a paint or coating formulation. The impact of additives on a formulation can vary depending on the application, but every component makes a difference. Green biocidal additives should be characterized by favorable human toxicology profiles. They should not cause substantial impact to the environment at use levels and should not be sensitizers. Silicon additives are absolutely necessary components of greener formulations. They can improve the longevity of paint, thus reducing the repainting frequency. They are often multifunctional, making it possible to replace two or three current additives with one. Surfactants and related additives, defoamers, dispersants, and other compounds that affect performance based on surface chemistry, are the easiest class of additives to target for developing green alternatives, since their chemical structures are well suited for synthesis from naturally derived materials.


While nearly everyone across the coatings value chain, including end users, agrees that environmentally friendly products are desirable, there is a disconnect when it comes to paying for a more sustainable profile, “If current coating solutions are working for their customers and there is no regulatory drive to switch, then most end users will stay with that current technology.” Cost is a crucial factor, but many also have concerns about the long-term availability of greener or more sustainable materials— they want a that the new green products will be available for the expected lifetime of the products for which they will be used. Therefore, as green products are developed, they need to meet, or surpass, performance levels without adding cost. That can be an issue, because green products may be perceived as having the same, or worse, performance than other products while costing more. There is real demand for products that help manufacturers reduce energy consumption by requiring shorter bake times and lower curing temperatures. There has, in fact, been significant pressure from manufacturers on suppliers to make raw materials greener and more benign without compromising performance. Products with “zero-VOC” or “low-VOC” labels has continued to grow. There were initially performance challenges with low-VOC formulations, such as microfoam, blocking, compatibility, freeze/thaw resistance, open time, tack, dirt pickup, scrub resistance, and more, but there is a much greater range of available technologies today that help formulators improve the performance of paints and coatings while also meeting regulations and consumer demand for a small environmental footprint. points to new generations of low/zero-VOC products, high-performing coalescent, pigment dispersions, resins, reactive modifiers, tougheners, defoamers, and others, some of which may also incorporate biorenewable feedstocks such as plant-derived oils, fatty acids, and esters, or may avoid particular substances of increasing concern (formaldehyde, APE, bisphenol A, phthalates, etc.). Sustainable innovation is, in fact, occurring at both the process and product levels. Wet-on-wet processes are an ideal example of a new method that improves customer operations. the technologies aimed at reclaiming the water used during paint reduction, the formulation of higher-solids waterborne paints to reduce water consumption in products, as well as the costs and CO2 emissions associated with shipping latex, and improving dirt pickup resistance to reduce the need for washing and repainting, which can also help achieve water conservation goals. Across general finishing applications (metal, wood, composites), new resin developments have enabled reduction of air emissions and hazardous waste and elimination of chemicals that may potentially harm applicators. New polyurethane formulations, for example, not only provide a way for end users to meet environmental standards, but also to reduce energy consumption and inventory levels. In fact, advances in product and process environmental profiles have typically led to the need for advances in other technologies to maintain or achieve greater performance properties.


Coating manufacturers across the globe are continuously looking for new innovations that will push the industry to a greener future. The renewables and recycled materials are crucial elements in the implementation of a green agenda. For example, both bio-renewable materials that remain in backers and a bio-renewable polyester resin system for interior coil applications. They use recycled bio-renewables like vegetable oil, which is an effective substitute for fossil fuels. Another example is the use of both virgin vegetable oil and recycles or used oil. These products contain a resin system composed of up to 30 percent bio-renewable products, resulting in a sustainable finished product that doesn’t lose bio-renewable materials during the curing process. Used predominantly in the coatings developed for backers, giant coils of sheet metal are turned into all types of pre-painted construction products. These materials are not only eco-friendly and sustainable but can be achieved without any significant cost to the coating material.

The coating materials are also going green by changing the processes they use to handle coating-related waste. In anodizing, for example, manufacturers can use chemical flocculants that bind the toxic, waterborne aluminium hydroxide into a solid that can be compacted and handled more easily. They may also employ advanced drying technology to remove most of the water from the sludge created by the flocculent. In some cases, this leftover material contains so much aluminium – which would otherwise go into a landfill or leach into the environment – that it can be recycled and used in the production of other aluminium products.

And recycling plays other roles in helping coatings be more earth friendly. There are, however, still questions about how the impacts of raw materials and coating products should be measured. If, for example, an oil-based chemical is replaced with a renewable-based chemical, is it better for the environment? The answer is: that depends on the energy footprint it takes to make the renewable-based chemical relative to the oil-based chemical, and it also depends on how the renewable process impacts other uses of the same resources. “It is very important to the industry that all of these considerations be accounted for to ensure that we truly make the right choice for a sustainable future.”


Paint and coating industry

British coating federation

Hydrocarbon Magazine, Oct 2014 and Scientific Design

European coating

Coating world

ResearchGate Coatings_Based_on_Renewable_Resources_Synthesized_by_Advanced_Laser_Techniques

Science Direct

ResearchGate based_on_renewable_materials

ResearchGate renewable_resource_for_industrial_coatings_and_polyurethane_foams

ResearchGate Characterization_of_Renewable_Resource_Based_Green_Epoxy_Coating


Team CEV,

By : Sanidhya Somani,

ECE Department (2 nd Year)


CEV - Handout