The Importance of Silica Filler Research

The combined need for environmental accountability and for greater economic efficiency has created an unprecedented atmosphere for advancement in automotive research and development. From the perspective of environmental sustainability, researchers have sought, and attained great progress in the increased efficiency of traditional vehicle engines, the use and study of alternative liquid fuel sources, and have fostered an unprecedented interest in hydrogen fuel cell technology to curb greenhouse gas emissions. Furthermore, research in both vehicle body design and composition has led to higher aerodynamic standards, and the development of lighter, stronger, cheaper alloys. The second half of the boom in road vehicle research has been made necessary by recent unfavorable economic conditions; resulting developments include strategies for lowered production costs, increased fuel economy, improved durability and longer product life. However, only in recent years has an easily overlooked aspect of vehicle development come into serious consideration: that is the need for further development of the tires used on these vehicles. Some of the recent advances in this area of automotive science have led to greater tire durability, economic efficiency, and safer performance. An integral aspect of how the tire performs is the chemical composition of the materials used in their production, which is to say the least, a dauntingly complex topic. One specific improvement though, which has had resoundingly positive results in tire development, is the use of silica-based fillers, rather than the traditional, carbon-based alternative. This application of silica has led to increased efficiency due to reduced rolling resistance and better traction. In order to take full advantage of the positive properties of these silica-based fillers, it is critical to understand the chemical foundations that lead to these improved physical properties.  This can be accomplished by examining in detail the interactions of the filler compounds with the surrounding matrix of binding agents and rubber mixtures. A clearer and more in-depth understanding of these chemical interactions will lead to refinement of their applications to tire research thus leading to yet another level of economic efficiency and environmental sustainability.  

How to Determine Acidity of two or more Organic Compounds

Given two different acids, you will need to determine which is the most acidic. This seems like a daunting problem, but there are in fact only a few intuitive parameters with which to determine the answer.

The ability to determine which acid, acid A, or acid B, is the most acidic is a good skill to develop for taking tests, and also a skill that has practical importance in the laboratory. To answer this question, you can follow the simple steps outlined below.

1)      Find the most acidic hydrogen in molecule A, and in molecule B separately by following these three criteria:

a.       Look at the atom to which each hydrogen is bonded and find which is the most electronegative (remember that electronegativity increases UP and to the RIGHT on the periodic table)

b.      What is the hybridization of the atom to which the hydrogen is bonded? Just remember the trend that SP³ is least acidic, and SP is most acidic

c.       Now imagine that the hydrogen you chose is dissociated, what will the resulting conjugate base look like?

                                                               i.      Is there a highly electronegative atom in the structure that could lead to the inductive affect? If there is, then the inductive effect leads to a more stabilized conjugate base, therefore a stronger acid

                                                             ii.      How many resonance forms are available to the conjugate base? The more resonance structures, the more acidic is the hydrogen

2)      Now that you have chosen the most acidic hydrogen of each molecule, compare the two by using the same rules as above.

3)      Label one of each set of hydrogen atoms

4)      Draw the resultant conjugate of each version of the acid

5)      Make a table for each of the four criteria and each of the acidic hydrogens

Criteria	Hydrogen 1	Hydrogen 2	Hydrogen 3
Electronegativity of connected atom
Inductive Affect
Hybridization of connected atom
Resonance forms of conjugate

An interesting discussion

I came across this thread, on Chemical Forums today, which delves into the molecular structure and resulting physical properties of Teflon (as in the lining of non-stick frying pans).

I followed the link to a very well written article (http://www.chemguide.co.uk/qandc/ptfe.html) and really enjoyed the open-to-discussion-and-critique nature of the article, as well as the very plain, yet academic tone of the author.

As a result, the presentation makes perfect sense to me, and I look forward to watching research develop the next steps in the understanding of Teflon's properties (hopefully) in the near future.

Calcium Carbonate, Mollusks, and Body Armor

The following is a summary of the results of the MIT research outlined in this article: http://newsoffice.mit.edu/2014/tough-nails-yet-clear-enough-read-through

This article by David L. Chandler outlines the results of work done by student Ling Li, and Professor Christine Oritz. The author begins by describing the characteristics of the Placuna placenta shell, revealing that despite being made of a substance called calcite, that is usually weak, brittle, and crumbly, it is in fact extremely resistant to puncture damage and is optically clear. Calcite is a structural derivative of calcium carbonate, with the molecular formula of CaCO3. The research revealed that the hardness and optical clarity are brought about by an unusual nanostructure that has great potential for energy dissipation. 

To test this, the scientists inflicted multiple punctures with a diamond needle point, and then utilized 

Colorized SEM of the punctures.
(Ling Li)

Electron Scanning to examine what exactly happens to the structure. These tests revealed that the damage resistance of the armor is actually the result of the atomic-level physical structure called twinning. This structure occurs when the atoms in the boundary of a crystalline lattice “cube” are shared by two crystal growths, producing a mirror image. The author states that a repetition of this pattern provides an exceptionally strong barrier to damage when a physical puncture takes place, more efficiently keeping the wave of damage from spreading outward like a crystalline “domino action.” The author fails to explain this in great detail, but does add that this is the action that also preserves the optical clarity of the surrounding structure, and that it results in a structure that is 10-times more efficient in energy dissipation than pure minerals. 

The macroscopic results of twinning. This one is Pyrite.
(Public domain) 

It is stated in the article that the applications of these findings are mostly found in military body armor projects. Ceramic armor plates in recent use have proven successful only in one-shot circumstances, as the first impact greatly weakens the physical integrity of the entire system. These research findings are particularly significant in this aspect, as the mollusk’s armor can resist multiple punctures with little resistance lost. 

References

David, L., Chandler. (2014, March 30). Tough as nails, yet clear enough to read through. Retrieved from http://newsoffice.mit.edu/2014/tough-nails-yet-clear-enough-read-through

Ling Li and James C. Weaver. (2014). The Effects of Multiple Indentations [Scanning Electron Micrograph] retrieved April 10, 2014, from http://newsoffice.mit.edu/2014/tough-nails-yet-clear-enough-read-through

Method for Finding pH in One-Step

When I reached the acid-base calculation section of my freshman chemistry course, I struggled with it significantly.

After what seemed like hours of research, I found a series of AB tutorials on You Tube by the channel, “WoodsonChem.”

Once I figured out the basics of working the problems through these tutorials, I noticed a repeated pattern, an observation that saved me a lot of time while taking the section exam, and got me a good grade; I eventually "boiled down" the whole set of equations into one step...

The one-step method for finding pH:

Given a ka value, and a molarity for a weak acid, the following applies:

•          -log (sqrt[(ka)(M)])=pH
•          And for good measure, 14-pH=pOH

I hope that this will be useful.

Resources:

Woodson Chem. Retrieved from, https://www.youtube.com/watch?v=QQYmE0ZISq0