Surface chemistry and interface science

Junbai Li *a and Krister Holmberg *b
aInstitute of Chemistry, Chinese Academy of Sciences (CAS), Beijing, China. E-mail: jbli@iccas.ac.cn
bChalmers University of Technology, Department of Chemistry and Chemical Engineering, SE-41296 Gothenburg, Sweden. E-mail: krister.holmberg@chalmers.se; Tel: +46 730 794215

Received 29th June 2017 , Accepted 29th June 2017
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Junbai Li

Junbai Li received his PhD from the Department of Chemistry, Jilin University in 1992. He then served as a postdoctoral fellow at the Interface Department of the Max Planck Institute of Colloids and Interfaces in Germany from 1994–1996. He is currently a professor at the Institute of Chemistry, Chinese Academy of Sciences. He has published 260 papers, written and edited 4 books and contributed 8 book chapters. He is the owner of 18 patents. His main research interests are in molecular assemblies of biomimetic systems, self-assembly, biointerfaces, and the design and synthesis of bioinspired materials with various nanostructures.

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Krister Holmberg

Krister Holmberg is Professor Emeritus from Chalmers University of Technology in Gothenburg, Sweden. Before he joined Chalmers in 1998 he was Director of the Institute for Surface Chemistry in Stockholm and prior to that he was Research Director of what is today AkzoNobel Surface Chemistry. He has published more than 300 papers, written or edited 7 books and he is the inventor of 35 patents. He is a member of the Royal Swedish Academy of Sciences, the Royal Swedish Academy of Engineering Sciences and the Royal Society of Arts and Sciences, of which he has been President.


This themed issue has the title “Surface Chemistry and Interface Science”. The word ‘surface’ usually means a solid or liquid interface against a gas phase (or vacuum); thus, the terms ‘surface’ and ‘interface’ are partly overlapping. However, both are frequently used in the scientific literature and they are often used interchangeably. We therefore believe that the chosen issue title is appropriate. Much of the research in the area relates to the behavior of amphiphilic substances, which are molecules with a strong driving force for interfaces. At the interface the amphiphiles often self-assemble, typically forming monolayers or bilayers. This self-assembly is not restricted to interfaces, however; amphiphilic molecules also self-assemble in the bulk phase. This is a very common phenomenon in aqueous solutions and it may also take place, although with less energy involved, in polar organic solvents. (Self-assembly may also occur in an apolar organic solvent if a small amount of water is added.) The fact that amphiphiles self-assemble both in the bulk and at interfaces has in practice also meant that phenomena in the bulk involving amphiphilic substances are included in the context of surface chemistry and interface science. This is currently an area that spans the fields of chemistry, physics, materials science, and biology and it is a highly dynamic scientific domain.

Interfacial phenomena are today studied by a broad range of analytical techniques, many of which are highly advanced. One may say that the development of the field has gone hand in hand with the development of the analytical tools needed to characterize phenomena at interfaces and self-assembly processes in the bulk. It is interesting, and a characteristic feature of this discipline, that practical aspects of the research are often very visible. The step from basic research at highest scientific level to practical problem-solving can be short.

It is appropriate in this Editorial to point out that surface chemistry and interface science is a discipline that dates back thousands of years. This relates to many subfields of the science, such as lubrication, adhesion and corrosion protection but the most well-known is probably detergency. The Babylonians and the Egyptians in ancient times knew that an efficient soil-releasing compound, today called ‘soap’, could be obtained by the treatment of animal fats by pot ash or some other form of alkali.1,2 Soap prepared from long-chain triglycerides continued to be the work horse of detergents up to World War 1, when synthetic surfactants, such as branched-chain alkylbenzene sulphonates, took their place.

Applications of surface chemistry and interface science can be found everywhere and all types of interfaces are involved. The air–water interface is relevant to foam applications, the gas–solid interface to heterogeneous catalysis, the interface between water and an organic solvent is the basis for emulsions, the adsorption of synthetic surfactants as well as polar lipids and macromolecules occurs at the solid–liquid (and the air–liquid) interface, and the solid–solid interface is important for composites and metallurgy.

During the last few decades surface chemistry and interfacial science have become extremely important in the biological sciences and in materials science. Charles Tanford3 and Toyoki Kunitake4 demonstrated that the principles developed for synthetic amphiphiles, surfactants and surface active polymers could also be applied to biological systems. The groups of Kuroda,5 Beck6 and Stucky7 showed how amphiphilic compounds could be used as templates for making inorganic materials with almost perfect control of size and morphology. Marie-Paule Pileni has pioneered a procedure for the synthesis of nanomaterials with specific morphologies from self-assembled surfactant systems.8 Research at the borderline between interfacial chemistry on the one hand and biology and materials on the other hand continues to develop rapidly.

This themed issue demonstrates the current breadth of the research in surface chemistry and interfacial science. Several papers deal with fundamental aspects of the science, and basic concepts such as forces between surfaces in close proximity and the importance of various intermolecular forces for the self-assembly of molecules are revisited but with different objectives and with partly different methods compared to the studies published a few decades ago. Even such an old issue as the cleaning of hard surfaces has been revisited, this time with a very specific application in mind, the removal of soil from works of art, and with the use of very sophisticated characterization tools.

A large portion of the contributions relate to applications of the science. Many of these papers deal with biological problems and it is clear that surface science nowadays plays an important role in the understanding of many events in biological systems. Some of the papers go far into the biology and explore therapeutic aspects, e.g. cancer treatment.

From the list of contributions it is also apparent that materials science continues to be an important application for surface chemistry and interfacial science. This relates both to organic and inorganic materials and it comprises colloidal systems as well as macroscopic objects.

References

  1. J. R. Partington and B. S. Hall, A History of Greek Fire and Gun Powder, JHU Press, Baltimore, 1999 Search PubMed.
  2. M. Wilcox, Soap, in Poucher's Perfumes, Cosmetics and Soaps, ed. H. Butler, Kluwer Academic Publ., Dordrecht, 10th edn, 2000, p. 453 Search PubMed.
  3. C. Tanford, The Hydrophobic Effect, Formation of Micelles and Biological Membranes, Wiley, New York, 2nd edn, 1980 Search PubMed.
  4. T. Kunitake and Y. Okahata, A totally synthetic bilayer membrane, J. Am. Chem. Soc., 1977, 99, 3860–3861 CrossRef CAS.
  5. T. Yanagisawa, T. Shimizu, K. Kuroda and C. Kato, The preparation of alkyltrimethylammonium-Kanemite complexes and their conversion to microporous materials, Bull. Chem. Soc. Jpn., 1990, 63, 988–992 CrossRef CAS.
  6. C. T. Kresge, M. E. Leonowicz, W. J. Roth and J. S. Beck, Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism, Nature, 1992, 359, 710–712 CrossRef CAS.
  7. D. Y. Zhao, J. L. Feng., Q. S. Huo, N. Melosh, G. H. Fredrickson, B. F. Chmelka and G. D. Stucky, Triblock copolymer syntheses of mesoporous silica with periodic 50 to 300 Angstrom pores, Science, 1998, 279, 548 CrossRef CAS PubMed.
  8. M. P. Pileni, Role of soft colloidal templates in the control of size and shape of inorganic nanocrystals, Nat. Mater., 2003, 2, 145–150 CrossRef CAS PubMed.

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