Evonik’s ULTRASIL Tires increase fuel efficiency

Company Profile:

Evonik Industries is one the world’s lead specialty chemical companies. One of the main goals of the company is to provide product that solve problems and provide a maximum benefit to customers and society. Recently, they have developed a more fuel efficient tire that does not compromise on performance through the implementation of a silica-silane system, known as ULTRASIL.

ULTRASIL:

The greenhouse effect is a natural process in which radiant heat from the sun is captured in the lower half of the atmosphere, directly resulting in higher temperatures and thus global warming. In order to reduce this greenhouse effect, most companies are working towards minimizing carbon dioxide emissions from transportation. Carbon emissions from combustion of energy fuels has accounted for 81.5% of total greenhouse gas emissions over the last several years, and global warming is quickly becoming a major problem throughout the world. Transportation contributes to this on a large scale, and it is responsible for 31% of the CO₂ emissions from the United States. However, Evonik’s silica-silane system (ULTRASIL) is a unique approach to this problem. ULTRASIL is created in several different forms and is applicable in many different situations, however its primary purpose is to serve as a coating for tires. This advanced tire technology can reduce the rolling resistance of tires, increase traction in wet conditions, and reduce carbon dioxide emissions. In general, tires have been targeted as quick way to reduce carbon dioxide emissions, as simple changes in size and shape can increase fuel efficiency by up to 15%.

ULTRASIL is able to reduce rolling resistance between tires and wet or icy road conditions due to the presence of intermolecular forces (IMFs), which can determine whether a solid will be hydrophobic (resists water) or hydrophilic (attracts water). This is an important concept to the concept of ULTRASIL because it is produced with hydrophobicity in mind. Being hydrophobic, water will adhere to the ULTRASIL coated tires, resulting in increased traction between the tires and the road. The major types of intermolecular forces that impact hydrophobicity include dipole-dipole forces, hydrogen bonding, ionic interactions, and London dispersion forces.

Dipole-dipole forces, hydrogen bonding, and ionic interactions are all known to be hydrophilic interactions. The larger presence of these forces in a molecule, the more the solid will attract water molecules. Dipole moments in a molecule are dictated by the polarity of a molecule. Polarity is the sum of all of the bond polarities in a molecule, resulting in dipole moments. The dipole moment is measured in a vector as the sum of the individual vector movements. For example, CO₂, a linear and non-polar molecule, has no dipole moment. Hydrogen bonds are the interactions of a hydrogen atom with a nitrogen, oxygen, or fluorine atom. They are a much more powerful force than dipole-dipole forces, resulting in a larger increase on the hydrophilicity of the molecule. Similarly, the presence of ionic bonds (interactions between positive and negative ions) can have the same effect.

London dispersion forces, the weakest of the intermolecular forces, are the sole forces that can raise the hydrophobicity of a molecule. This force, also called an induced dipole-dipole force, is a temporary attractive force that results when the electrons in two adjacent positions occupy positions that make the atoms form temporary dipoles. These forces occur in all molecules. In the production of ULTRASIL, Evonik has created a silica-silane system, where the hydrophobic regions of the molecule dominate, causing adhesive forces to arise and increase the tension between tires and wet/icy road conditions. More information about intermolecular forces can be found here, or

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Also, the chemical structures of the silica helps contribute to its unique properties. Silicon dioxide can exhibit one of the largest varieties of crystal structures among the compounds commonly available and used. These many different crystalline forms allow silica to be used in a broad range of applications, including ULTRASIL. Precipitated silica, which is key to this product’s functionality, is a specially prepared form that has an amorphous structure, similar to silica gel or glass, both of which are predominantly silicon dioxide, or silica. As already discussed, adding these silicon dioxide granules to the surface of rubber tires has many beneficial effects on vehicle performance, but binding this hydrophilic molecular solid to the long, continuous, and hydrophobic polymer chains that make up vulcanized rubber can be difficult. It is up to sulfur, linking the polymers of vulcanized rubber to make it more resistant to temperature extremes, to act as a coupling agent for silica, since the hydrocarbon polymers will not bond to it by themselves.

From what we know, however, ULTRASIL production takes a rather different approach to solving the problem of coupling silica to rubber: the silica-silane system. By treating the original rubber  material with various organosilanes, a surface that silica particles can easily bond to is created, making it possible to form the desired composite with more cross-links to the silica granules and a higher overall thermal stability than without the treatment. Organosilanes usually have both a nonpolar and polar end and can not only bond with vulcanized rubber, but also with the silicon dioxide particles, through dehydration synthesis of their hydroxyl groups with the hydroxyl groups that cover the surface of the silica particles.

While many of the specific details of the ULTRASIL manufacturing process are trade secrets of Evonik, the company does share the basic concept of how it obtains the very pure amorphous silica needed for its products: precipitation from solution. Precipitated silica is widely used in industrial processes around the world, and Evonik Industries is its largest producer. Just like in ULTRASIL, these fine silica grains are often used in rubber products like tires and shoe soles for benefits similar to those of Evonik’s products. Generally, an aqueous silicate salt is reacted with an inorganic acid (like H₂SO₄) to form insoluble silica in the following reaction:

Na₂SiO_3(aq) + H₂SO_4(aq) → SiO_2(s) + Na₂SO_4(aq) + H₂O_(l)

    After the silica precipitate has been dried, it still contains no more than 88% silicon dioxide according to Evonik, with most of the rest being water. The ensuing treatment to purify the product varies depending on the desired size and quality of the particles obtained, but eventually a fine powder consisting of 99% silica can be obtained. The precipitated silica used in the ULTRASIL product line consists of miniscule, porous granules often of nanoparticle size to allow a high surface area to volume ratio, with the 7000 GR variant having a surface area of 170 m² per gram. It is this kind of fine silica that allows for the reinforced rubber of the emerging “Green Tire” that advances in silica rubber have created.

Further Reading:

If you are interested in the chemistry behind Evonik’s ULTASIL, there is a lot of in depth reading available in scientific journals. A thorough account of this technology and the chemistry that drives it can be found

• In this study by Brinke, Debnath, Reuvkamp, and Noordermeer
• And this article by Park and Cho

Newlight Technologies: Plastic from Thin Air

Company Profile: Newlight Technologies, LLC

Newlight Technologies, founded in 2003 has just recently brought its innovative, game changing products to market. Through a patented carbon-sequestration process using biocatalysts, Newlight technologies is able to extract carbon from greenhouse gasses in the air and convert them to AirCarbon, a high performance thermoplastic that serves as a highly viable substitute to oil-based plastics. AirCarbon plastics aren’t simply low carbon, or carbon neutral; requiring less carbon emissions to produce than used in production, AirCarbon is carbon-negative, having the net result of reducing greenhouse gas pollution. Amazingly, eco-friendly AirCarbon plastics are less expensive than oil-based alternatives. To this extent Newlight Technologies succeeds in creating a product that is eco-friendly, high performance, and commercially competitive; a recipe for success.

Check out this quick video from Newlight.

Thermodynamics

It is truely remarkable to consider the thermodynamic challenges to creating a product such as AirCarbon plastics. Qualitatively speaking, sequestering carbon from the atmosphere and using it to produce plastics represents a huge decrease of entropy within the system. Gaseous carbon dioxide and methane mixed in the atmosphere have a great amount of positional entropy, with gaseous molecules flying around in the atmosphere near-evenly mixed with a **tail of gasses that compose Earth’s atmosphere. To contrast, consider the neatly arranged polymer chain of carbon molecules that make up AirCarbon, the end result of Newlight’s process. The latter has considerably less entropy.

While the highly significant change in entropy of the system (the carbon used to make the plastics) by no means makes the process of converting gaseous carbon to plastic impossible, it is important to consider the constraint that the whole process is carbon negative — they have to expend less carbon emissions to make the plastic than carbon they sequester and transform into plastic.

Consider Gibb’s free energy equation:

In order for the reaction converting gaseous carbon emissions into carbon polymers to occur in a forward direction, free energy (G) must be negative. Given a large negative entropy (S) characteristic of a conversion from a gas to a solid, there must be an even greater negative change in enthalpy (H). In basic terms, the system must give off a lot of energy, making the reaction highly exothermic.

 

Molecular Structure of AirCarbon

The end product is Newlight’s trademarked AirCarbon, a high performance thermoplastic that can serve as an affordable and effective substitute to polypropylene, polyethylene, ABS, polystyrene, and TPU. AirCarbon is a thermoplastic, it is a plastic polymer that becomes pliable when heated. This makes AirCarbon appropriate for a number of industrial applications and makes it versatile for producing many products in many different ways.

A polymer is a macromolecule composed of small repeating subunits, called monomers. Step 3 of Newlight’s GHG to Plastic process gives an example of a monomer. A polymer is made by covalently bonding many monomers together, which could theoretically be extended infinitely. Through polymerization, monomers can be used to build long polymer chains or three dimensional networks. The example below shows a polymer chain of polyethylene, showing how the individual ethylene molecules are connected to create a continuous chain. An important difference to consider between the individual monomers and the polymer chain in this example is how the double bonded carbons in the monomer units become single bonds in the polymer. For a good introduction to polymer chemistry watch this video.

Because polymer chains are only covalently bonded in long linear chains, there are other molecular forces to account for in three dimensional plastics, primarily Van der Waals forces. Illustrated by the dotted lines, Van der Waals forces are relatively weak attractive forces that occur due to partial charges in polar molecules. Van der Waals forces can hold together lengths of a polymer chain, allowing it to form three-dimensional solids.

This also provides a ready explanation for how thermoplastics can be malleable when heated and solid, or even brittle when cooled. At high temperatures the kinetic energy of the polymer chain is able to overcome the Van der Waal forces holding it in a particular arrangement, so it becomes malleable. Once the polymer is arranged into its desired shape it is allowed to cool, allowing the Van der Waal forces to take hold and set the polymer in its shape. At very cold temperatures, there is less and less kinetic energy in the molecule to oppose the Van der Waals forces making them play a very significant role. At these low temperatures the forces are relatively strong, and make the material brittle, explaining why plastics crack easily at cold temperatures.

So What?

The beauty of Newlight Technology is that it is truly sustainable and truly convenient. Newlight offers a cost effective solution to create eco-friendly plastics, completely turning the tables when it comes to environmental sustainability. Plastic, normally seen as an eco-unfriendly and destructive material can now be part of the solution to pollution and global warming. AirCarbon is biodegradable, making it eco-friendly cradle to grave. It gets extracted from the atmosphere in a carbon-negative process, gets turned into a useful material for human expenditure, and then when it is put to waste (as it inevitably will) it breaks down back to the earth and the atmosphere. What is particularly promising about Newlight is the fact that its products are less expensive than their oil based counterparts, again defying the expectation that eco-friendly means more expensive or less convenient.

How Much is Enough? Synthesis of Muscle Protein and Nitrogen Balance as an Indicator of Adequate Consumption

When you consume protein, you are supplying your body with the amino acids and nitrogen to create structural cells, enzymes to carry out essential chemical reactions, hemoglobin to transport oxygen through the blood, hormones to regulate reactions, and non-protein nitrogen compounds needed for growth and maintenance of the body (nitrogen and amino groups in those amino acids are also used to make molecules such as nucleic acids, hormones, ATP, and

other bio-molecules). Protein contributes to the maintenance of the human body in a vast number of ways, and it is essential for many critical metabolic processes in the body. Because protein synthesis is necessary to carry out fundamental bodily processes, building muscle is among the least prioritized functions of protein metabolism. Consequently, it is necessary to induce a protein surplus in order to produce conditions where muscular growth is possible.

Nitrogen balance is the measure of nitrogen input minus nitrogen output. Unlike other macronutrients (fats and carbohydrates), proteins contain nitrogen in addition to carbon, hydrogen, and oxygen. Nitrogen typically enters the body via proteins, and leaves it mainly in the form of urea. So since most of our nitrogen intake comes from protein, measuring the loss of nitrogen (through tracers containing the rare but stable isotope nitrogen-15) can tell something about protein metabolism and synthesis. Because nitrogen is practically exclusive to proteins (In fact about 95% of bodily nitrogen can be linked to protein), nitrogen content in the body serves as a general indicator of adequate protein consumption:

Nitrogen Balance

• A negative nitrogen balance indicates a dietary protein deficiency. When nitrogen excretion exceeds nitrogen consumption, there is implied predominance of catabolic processes in the body — your body is breaking down proteins in the body to meet its metabolic requirements, thereby releasing the extra nitrogen which is then excreted. Your body has to break down the proteins it already has because it is not receiving enough dietary protein to carry out metabolic processes. In this case the body would be diminished because it is losing protein to carry out its metabolic processes.

• An equilibrium in nitrogen balance indicates sufficient protein consumption to maintain the body’s current status. When net nitrogen consumption is equal to net nitrogen excretion, anabolic and catabolic processes are occurring at roughly the same rate. The net amount of protein synthesized is for structural and functional use is equal to the amount of protein broken down. In this case the body would not grow or diminish, it would remain the same.

• A positive nitrogen balance indicates that there is a protein surplus in the body. A nitrogen surplus indicates that your body is retaining more protein than it is excreting, and that there is excess protein after all metabolic requirements. This surplus is a prerequisite (but not necessarily a guarantee) for a predominance of anabolic processes in the body. A positive nitrogen balance, therefore is necessary for growth — the synthesis of more proteins than necessary to sustain the body at its current state.

• For more information, check out this informative video

A positive nitrogen balance is an important consideration for anyone looking to build muscle mass because it is a strong indicator of protein surplus, which is a prerequisite for muscular growth. However, the issue of protein synthesis for muscle growth (or any type of protein) is dependent on having all of the proper amino acid precursors and specific enzymes to synthesize that specific protein. A study published by The Journal of Physiology states that the rate of muscle protein synthesis is directly increased through large extracellular doses of essential amino acids (those which your body can not produce) whereas they are not affected by doses of non-essential amino acids, although all 20 amino acids are required for protein synthesis. How does the amount of available amino acids affect the rate or extent of protein synthesis?

Amino Acid Concentration and Rate of Muscle Protein Synthesis

One contributing factor is the concentration of amino acids and other precursors to protein synthesis. Although complex, protein synthesis is still a chemical reaction which can be analyzed using kinetics. This study suggests that the rate of the amino acid utilization in muscle protein synthesis increases as their intracellular concentrations increase. This study demonstrates that the rate of protein synthesis can be described as a result of varying concentrations of precursors to the reaction. An increase in reactant concentration yields and increase in the rate of the reaction. However, it would be misleading, and a drastic oversimplification to assume that kinetic considerations are the only (or primary factor) that guide the rate of protein synthesis.

Protein synthesis is catalyzed by enzymes, which greatly increase the rate of protein synthesis reactions by reducing the necessary activation energy of the reaction. The body is a complex chemical system that has various responses to various stimulus. BCAAs (Branched Chain Amino Acids), a specific categorization of amino acids, are shown increase anabolism of protein synthesis by both increasing the rate of protein synthesis, but also decreasing the rate of protein degradation. A study published by the Journal of Nutrition states that BCAAs have a significant impact on protein synthesis by activating key enzymes, but also attributes increased muscular growth to other external stimulus, specifically intramuscular signalling, and exercise. This study suggests that the rate of protein synthesis is affected by numerous factors. For more information you can read the study here.

Protein is very crucial to many metabolic processes in the body, and contributes heavily to the growth of muscle. The amount of protein necessary to induce muscle growth can be considered to be enough so that a positive nitrogen balance is produced in the body. As proven in various studies, the rate of protein synthesis increases as the concentration of amino acids increases. This follows kinetic chemistry, as an increased concentration of reactants yields a higher concentration of products. However, protein synthesis is a very complex process involving a lot of parts, and ultimately can not be simplified to such basic terms. In order to synthesize muscle proteins it is imperative that all necessary precursors are available in the body, and the rate of synthesis is heavily influenced by enzymatic activity as well as other factors.