Self-Cleaning/-Degrading Hair

Andrew blogged about a 'nano TiO₂' shampoo some time ago; he didn't know the new application of the photocatalytic properties of TiO₂ in coating industry, the self-cleaning coating!

Self-cleaning coatings can be realized by either hydrophobic approach, the well-known Lotus-Effect^®, or the hydrophilic approach, the Activ^™ coating which mainly consists of TiO₂ photocatalyst. An 2005 paper (J. Mater. Chem. 2005, 15, 1689-1694. DOI: 10.1039/b412803f) has summed up the current research of this field. In the latter approach, photocatalysis causes the coating to chemically break down organic dirt adsorbed onto the window, while hydrophilicity causes water to form 'sheets' rather than droplets - contact angles are reduced to very low values in sunlight and the dirt is washed away (by this meaning I suggest the term 'easy-cleaning' rather than 'self-cleaning').

So introduction of TiO₂ into shampoo does make sense considering the self-cleaning and water-keeping properties thus gained (shampoo ads says hair to be best in the state of 80-90% dried rather than totally, one of a few things from ads that I do believe). But...how does the TiO₂ distinguish the organic dirt from hair (an organic host) and not subject the latter to photocatalysis as well?

Chemistry on a Compact Disc

Compact Discs(CDs) have proven to be versatile for modern chemical research. The recordable CD technology has been utilized to fabricate bio-CDs storing both numeric and genomic information (BioTechniques 2002 33, 435-439). Ligands are also 'burnt' on CDs to selectively bind proteins (Org. Biomol. Chem. 2003, 1, 3244-3249. DOI: 10.1039/b306391g). Besides utilization of the traditional CD technology, treating CD as a plastics surface and the subsequent nanofabrication is also interesting, e.g. SAMs (Anal. Chem. 2001, 73, 4743-4747. DOI: 10.1021/ac015521z) and oxide thin film (Anal. Chem. 2002, 74, 5742-5747. DOI: 10.1021/ac025686n) deposited on CD surface, and CDtrodes (electrodes prepared from CD-Rs, Anal. Chem. 2000, 72, 5503-5506. DOI: 10.1021/ac000437p). A mini-review written by the pioneer of this field, Hua-Zhong Yu, is available in Chem. Commun. 2004, 2633-2636. DOI: 10.1039/b412784f.

These days Andrew and his roommate, a part-time AFM manager, are considering possible cooperation between their fields, cyclodextrin and AFM. Cyclodextrin has successfully self-assembled into monolayers (Self-Assembled Monolayers, SAMs), the so-called 'molecular printboard' (Chem. Eur. J. 2000, 6, 1176-1183) and been subjected to multiple supramolecular interaction, by David N. Reinhoudt and co-workers. But if SAMs can formed on plastics with the current high-speed laser recording technology it would be more exciting. My new colleague, the ferrocene T-Shirt suggests the β-cyclodextrin SAM/ferrocene pair on CD surface in the hope of some redox sensitive properties. Quite fun, isn't it?

My new colleague

Ferrocene T-Shirt

Andrew bought a ferrocene T-shirt on SpreadShirt.com. He will wear it as much as possible. I suggest he add a β-cyclodextrin on the back so that the two can form a pair of inclusion complex (J. Chem. Soc., Chem. Commun. 1984 645-646. DOI: 10.1039/C39840000645) because the ferrocene on the front side is of the reduced form (without a little plus superscript). Anyway, how do you do my new colleague?

Recently the ACS Chicago gathering has attracted vast interest among the chemistry blogosphere. I am not in America and thus cannot engage in this event. But I still checked the agenda disclosed on The Chem Blog and found one speech which must be Andrew's favorite: Bioinspired supramolecular polymer chemistry by Steven C. Zimmerman at 3:05PM. Which chemical blogger will attend this lecture?

Best ad for chemistry

In the 19th century, chemists gave the world dyes and made our lives more colourful, in the 20th century, chemists gave the world drugs (pharmaceuticals), so lengthening our lives and making them more bearable, and, in the 21st century, chemists will give the world devices, making our lives much more fulfilled and immensely more enjoyable. These three d's are made possible by chemistry which is, in turn, about three m's – making, measuring, and modeling – and a lot more which could make our world a better place for better living for all of us.

--Sir Fraser Stoddart

This statement is quoted from the post series Reactions on Nature's blog The Sceptical Chymist. Sir Stoddart also disclosed in this interview that he admires literature very much and always dreams to be a novelist. He did show this passion in this statement by rendering the contribution of chemistry to modern human a romantic and vivid sense. If he is really going to write a novel I hope it is about a chemist or something that can sharpen the public recognition of chemistry. Maybe a sci-fic is a good choice because I seldom see chemistry-themed sci-fics. For example how will molecular switches and motors he is currently working on develop into a totally different life style of future human?

Photocopied Journalism

Thank you for applying for the summer science-writing internship at Chemical & Engineering News. Please excuse the delay in getting back to you. We received 38 applications for this internship, and it has taken more time than expected to consider them all carefully. Choosing one person was challenging because of the high caliber of the applicants. I am sorry to say that we have now decided in favor of another applicant. Thank you again for your interest in C&EN and for taking the time to apply for this position. I wish you well in your future endeavors.

Wow! 1 out of 38! So Andrew should not have expect anything from it because of the heat competition around here. He is from an English-as-second-language country with no journalism experience.

He borrowed a textbook from the library today, though, perhaps hoping to improve himself journalistically a bit. It is the famous News Reporting and Writing, 9th Ed. by Melvin Mencher. It is not an original edition which is available in US, but a photocopied version jointly published (by McGraw Hill) with a local Chinese publisher. I know this book from the recommendation of a undergraduate 师妹 majoring this subject.

Photocopied versions (legally by local publishers, with reduced prices of course) of foreign textbooks enable most of the Chinese students to afford the access of the best educational materials worldwide, although the prices are sometimes still quite high. Cell and Molecular Biology, Concepts and Experiments, 3rd Ed. by Gerald Karp, RMB 68. Supramolecular Chemistry by J. W. Steed and J. L. Atwood costs RMB 68.00, the same price of Flory's holy Principles of Polymer Chemistry. Solid State Physics by Neil W. Ashcroft and N. David Mermin, RMB 98. Isaac Neil's Physical Organic Chemistry, a classic, RMB 166.00. Vogel's Textbook of Practical Organic Chemistry, RMB 298. Random House Webster's College Dictionary, 385!

Ironically, if you really photocopy these books the cost may be much lower. Average price per A4 paper here is RMB 0.10. So take the Vogel's huge volume for example, the whole 1500 pages will cost only RMB 75 (two page per A4 paper) or less due to discount for such a large business. Actually Andrew photocopied the Advanced Organic Chemistry, Reactions, Mechanisms, and Structures, 4th Ed. by Jerry March, the whole book!

Finishing Reading all these book is another things of course, especially considering the cost. Fortunately Andrew read these book quite hard (except the recent-shopped Solid State Physics and Supramolecular Chemistry). But I doubt if it were not the high price, he would not have paid so much effort on them...

Learn everything only through reading papers?

I'm asking (wondering) more and more question as the use of question mark in the titles of my recent posts becomes frequent.

I like reading papers for its own sake - just reading. At first I read reviews of unfamiliar fields, and get familiar to them, then pay attention to outstanding papers in these fields. For example I used to skip mesoporous papers but after I went over a review on ACIE I can feel now the excitement of this field. I have also witnessed some fast moving fronts becoming new areas of worldwide interest, e.g. inclusion complex between cyclodextrins and linear polymer, colloidal crystal. Now I am wondering the possibility that I learn more behind these papers about the mechanism or way to kick-start clever, high impact growing fields. At least by comparing what a groups did before and after their clever thought, one may find out some clues about how to deviate an old project into its new life; that is how to 'suddenly' be inspired so much to publish on ACIE or JACS or Chem. Eur. J. Also, by tracking the line of a heated research from its first communication to the latest catch-up, one may gain some tips on how to develop a good idea into sustainable growth of a big area (rather than quenching it by stupid combinations and more combinations).

As the range of reading broadens one may know at the same time many new possibilities emerging very recently, and many even newer ideas based on the latest findings in different areas may keep flashing in one's mind. Very few of them, though, have the potential to be practically developed into valuable research fields, and I suggest the best way to learn the criteria of potential ideas is reading behind and beyond a large number of papers.

Andrew definitely doe not know all these because he, after reading (with me) so many, still choose an older-than-Mars-creature research for graduate thesis. What is unknown about cyclodextrin and PEG-b-PLA in water that need Mr. Andrew to work on it a bit? Recently he has been thinking playing around with 'molecular printboard', self-assembled monolayers (SAMs) of cyclodextrin and the subsequent supramolecular interaction with various guests, with a colleague and his best friend ever who manage an AFM. But everything seems to have been reached by David N. Reinhoudt's group with up till now more than 14 papers published. I still wish him a good luck.

What's your experience of reading paper? Do you think paper reading can mean that much? Or it is just my illusion?

Engineered Blood?

Nanoparticles bearing designed peptides in circulation selectively clot tumor vessels and amplify their own accumulation at that site, according to recent finding (PNAS 2007, 104, 932-936. DOI: 10.1073/pnas.0610298104).

The researcher first found a short peptide Cys-Arg-Glu-Lys-Ala (CRECK) that binds clotted plasma proteins in tumors. Then they attacth this peptides to iron oxide nanoparticles with diameter of 50 nm. The nanoparticles were found to accumulate only at tumor site and liver, but cause clotting in tumor vessels only, which involved no platelets.

The interstitial spaces of tumor contain fibrin and proteins that become cross-linked to fibrin in blood clotting. The presence of these products in tumors, but not in normal tissues, is thought to be a result of leakiness of tumor vessels, which allows plasma proteins to enter from the blood into tumor tissue, where the leaked fibrinogen is converted to fibrin by tissue procoagulant factors. The clotting creates new binding sites that can be identified and accessed with synthetic peptides like CREKA, with which the nanoparticles once modified can bind and induce localized tumor clotting. But the detailed mechanism of clotting is yet to be study, and it is unknown whether these plasma protein-binding nanoparticles would also affect other regions of pathological clotting activity in the body (e.g., wounds) and induce additional clotting at such sites.

John Salzi's recent science fiction Old Man's War describes the possibility to engineer every piece of tissue in human body into high-performance materials. As for the circulation system, the blood is in fact a solution of smart nanoparticles that have ultra-high capability of oxygen delivery and clot within seconds. Tumor homing is nice but blood engineering is more exciting. The next step of this study should point to faster clotting and higher oxygen loading features of well-defined nanoparticles.

Sublimation

Today I want to show some photos of Andrew's sublimation set up (click to enlarge).

Fig. 1 The equipment was made to my specification according to Vogel's Textbook of Practical Organic Chemistry, 5th Ed., pp. 154, Fig. 2.87

Fig. 2 Close shot. The purity of D,L-lactide plays a vital role in the controllability in its ring-opening polymerization with MeO-PEG.

Fig. 3 Vacuum pump set-up

Music?

A story on Intute suggested a possibility that most of the reagents needed in chemical labs be manufactured from extracts of celery and potatoes, or cassava and carrots and other inexpensive, locally available vegetable products and food waste, thus expectably lowering the budget burden on less-developed-country researchers.

As a country known for its portion of farmer population, where meanwhile chemical research is indeed widely constrained by high prices of imported reagents and devices, this 'renewable-reagent proposal' may be music to us on first glance. Even a little monomethoxy poly(ethylene glycol) (mPEG) (Andrew need this macroinitiator to kick started the Ring-Opening Polymerization of L-lactide for a diblock structure) is not available at all. As usual, Andrew tried a google search and only found Fluka had the MW he needed, though it's RMB 466 per 250g, quite economic comparing with his another needed compound α-cyclodextrin (RMB 2737 per 25g, and he bought from native supplier alternatively with RMB 380 per 50g), or other routine reagents like n-BuLi (RMB 535 for 100 ml of 2.5M solution in hexane)^†. When it comes to characterization, usually we have to visit other institutes because we don't always have all the devices needed. Take the Guangzhou Institute of Chemistry, CAS for example, an XRD scan is RMB 150 per time (RMB 300 for additional spectro-analysis service), an ¹H NMR RMB 120 per sample (¹³C doubled), GPC RMB 100 per sample, TEM RMB 150 per sample (RMB 15 per Cu net)...Considering the reasonable frequency of some of these characterization as well as the cost of all reagents, to complete a graduate thesis you may need RMB 3000-5000, or even more.

To save money we usually buy local products if available. They have much more pleasant prices, but the quality is sometimes unacceptable. A well-known story: paper on Angew. Chem. Int. Ed. recalled by a Chinese group due to miniature moisture in the reagent from Chinese supplier, leading to a wrong result. It is also quality problems that prevent us to try native devices, which are also limited in types and techniques (e.g. we have no native electric microscope manufacture). And institutes tend to charge high detecting fees for outsourcing business to compensate their expense on imported devices.

So I guess techniques like cutting the cost by renewable-based chemical production may not help us much.

† Prices according to Sigma-Aldrich China Mainland.

Undergraduate Project

On the first day of the new term 13 senior undergrads gathered in the supervisor's office. They will complete their graduate project in our lab. What's absurd but common in China is they have only 10 weeks or so.

We have 2 terms per years in university divided by two long vacations, summer and winter. New academic year starts after the summer vacation, usually in September. So, the new term I am talking just now is the second term of their last year in university, or literally the last term. They have to first spend two weeks to attend the graduate internship in a factory (this year a synthetic fiber plant), so they can only start their graduate project in the fourth or fifth week. Deadline is usually early June. So actually they have two months for the project. What's worse, this period is overlap with the best and last opportunity for the undergrads to find a job, so most of them will slip the lab from time to time.

For something to come out in two months, experiments are not allowed to repeat or fail. They must be successful in one time. If Andrew were them and saw this as what real scientific research is like, he would hate science and wouldn't believe in it for his entire life. The least timespan for a reasonable chemistry project should be one year. Andrew spent one year on his graduate thesis, and he followed up the whole process. But he was lucky to do so - he had decided to apply for M.S study so did not have to find a job. He was free the whole forth year.

As for the content of the project, almost without exception, the undergrads will choose among the exist grads' projects. The grad involved (e.g. Andrew) is responsible to help the undergrad who choose to follow him/her to complete his/her thesis. The word 'help' here can mean either angel or evil. An angel senior fellow (see cultral tips) will act as a supervisor to his junior and just, you know, be an angel (with some divine but invisible implications every time the junior is confused). An evil fellow give his junior even more freedom, allowing him/her to be absent from lab, and even write the thesis for his junior. I hear this is quite common in Andrew's college (of MSE).

Cultural Tips

In China, we have unique title to call the senior fellows in the same lab, department or generally university. The meaning of the title in English is 'brother/sister under the same master' (Chinese: 师兄 or 师弟 for elder or younger brother, 师姐 or 师妹 for elder or younger sister), either senior or junior depending who you are calling. They are more heavy in moral content than 'senior fellow' or 'dude' or 'bro' in English.

I assume most of you know about Chinese Kong Fu. If you want to learn some Kong Fu you have to pay a visit to an expert and ask him to be your master. Usually the expert may examine your potential (for example whether your bones is suitable for Kong Fu training). And it is usually hard to become an apprentice of a great Kong Fu master. If you succesully become the new apprentice of your master you will also meet some of his other elder apprentice. In Chinese culture, master is like your father, so all his apprentices are his sons. Therefore you should call your senior fellows brothers or sisters like they indeed are. You should also call the wife of your master 'master mother' (Chinese: 师母), and the ancestors of your master 'master grand grandfather' (Chinese: 师祖）.

We borrow these titles as well as the morality in modern academic institutes because of the similarity in situation to an above mentioned Kong Fu family. So automatically my junior fellow is like my little brother/sister and I am his big brother/sister. This is exciting for both. I will help him/her in every aspect in his/her life and he/she will learn from me with whole heart. In fact as you can imagine, many lovers in university are developed from initial 师兄~师妹 relationship (master elder brother and master younger sister). Bachelors like Andrew (by bachelor I mean singles) should mostly hope to find their sweethearts among 师妹. That's very interesting.

Defining Materials Chemistry?

I came across this issue in a post on The Sceptical Chymist. I want to share my understanding here:.

Materials chemistry or the whole materials science is the research and application of the structure-function relationship of matter.

Therefore, the foundation of the structure-function relationship, physical chemistry, play a core role in materials science. The so-called 'polymer physics' is in fact a physical chemical approach to address the unique viscoelastic properties of these macromolecular aggregates, by analyzing chain structures and the secondary (non)crystalline structures. Similarly the discipline called 'solid state physics' is a physicochemical analogue to 'polymer physics' in term of inorganic materials. Anything needed is utilized here: quantum mechanics, statistics, group theory, etc. These are the research parts of material science.

Based on the understanding of the structure-function relationship, we start to synthesize materials with expected structures (functions) - the application part of material science. That is why for instance 'polymer chemistry', chemistry of the formation and reaction of long-chain macromolecules, is needed. And we have also a wide variety of processing methods (physics) of plastics, rubbers, metals and ceramics.

In particular, nano-scale properties of matter have received high concerns these years, paving the way to novel nano-materials. This is again the result of our increasing understanding of the structure-function relationship in the nano-scale.

Parctice is the Only Criterion of Truth

This is not a thesis. I'm not going to fully elucidate this idea with perfect logic and plenty of supporting material, but to simply put what is already clear in order.

The Criterion

'Practice is the Only Criterion of Truth' (Chinese: 实践是检验真理的唯一标准, click to enlarge the snapshot on the right)is a title of an editorial of Guangming Daily on May 10th, 1978, a critical point in Chinese modern history when the Cultural Revolution had just ended and people were confused between the right and the wrong, the real and the fake. As the core of our ideology, the Marxism should be the only source to seek for the answer. Fortunately we sought one then. The 'only-criterion' article has a profound effect on the later history of China, because it totally freed people's mind and make available any possibility on this land. Every student here now know this famous saying.

The Limitation of Practice

At the front-line of unknown truth, scientist (at least Chinese ones), surly cannot understand this criterion better. Galileo's experiment on the leaning tower of Pisa set a perfect example for us. However, Newton mechanics, which has been proved by almost all practice, was still challenged and had to be developed after Einstein's theory of relativity was (or its deductions were) also proved by new and coming observations.

When practice is limited by the environmental condition at the moment, the truth so obtained is accordingly limited. Human develops his skill of practice, that is, technology, for a wider and deeper coverage. The establishment of the theory of relativity was obviously owing to our the enhanced ability to see into the space with stronger telescopes.

'Useful' Truth

Because the universe is infinite, our practice is always partial, and so is our 'truth' at the same time. But it is impractical, if not impossible, to pursue the 'ultimate' knowledge of the universe right away. It is well enough to know what is useful for the current practice. We don't consider the mass increase when dealing with an accelerating car (in fact we may be clever enough to consider the air resistance instead), because Newton mechanic is useful enough. We need only 'useful' truth, by useful I meaning consistent with current practice.

Inconvenient Truth

If each of us could tolerate the imperfection of truth about physical world, I'm sure much fewer would allow such imperfection in knowledge about our bodies and the treatments on them. This is why medical science is often chosen for target by anti-science powers. Similarly, for those theories that are hard or impossible to proved by practice (experiments, observations, etc.), like the one of evolution which could only thrive on evidences, people can literally act as members of the jury in a court and judge its truthfulness by their own believes. The arbitrariness here is again music to anti-scientists.

This problem is somewhat beyond the Practice Criterion. It concerns the nature of science, and its relationship with truth or human knowledge. Still there have been legendary answers to this issue, of which I only recommend two here: Dialectics of Nature by Friedrich Engels and Human Knowledge by Bertrand Russell. All I want to mention here is that science, although not necessary a religion, indeed has presumptions or postulates that need to be held a priori.

Not Listed in Google

I have tried the Google's webmaster tools several times but my blog still failed to be listed in its index. However, it is listed in Yahoo!. Maybe the URL is too complex and not meaningful enough (with such irrelevant words as af2006, x25, 51web, etc.) for Google. I'm considering a change in the domain name. Blogspot.com is not a good choice because it has a long history of being blocked by the GFW of China. It is released only very recently. Maybe I need to register a domain name that contains a minimum of words other than 'on the road', something like ontheroad.com or on-the%20road.net, or even roadtheon.cn, whatever.