Polymer theory, modem, development

It should be emphasized that stabihzation of metal nanoparticles by high-molecular compounds presents a major branch of polymer colloidal modem science. Modem polymer colloidal science studies generation regularities of dispersed systems with highly developed interfaces, their kinetic and aggregation stabilities, different surface phenomena arising at the interface, and adsorption of macromolecules from liquids on solid surfaces. The theory of improving stabihty of colloidal particles by polymers has been treated in detail elsewhere. This chapter focuses on basic questions that are connected with nanoparticles and nanocomposites. 

Around the turn of the twentieth century, modern atomic theory wreis developed, and chemistry became a mainstream science through which new materials could be produced. Each new material engendered new apphcations, and each new application played to a demand for stiU newer materials, mostly derived from coal tar, of which a ready supply existed. The final key requirementwreis the discovery and development of polymerization. The first completely synthetic polymer, compounded from phenol and formaldehyde, was developed in 1907 by Belgian chemist Leo Hendrik Baekeland. It proved to be the elusive material needed to expedite the mass production of consumer goods. Soon, many other new materials were created from polymerization, which led to the development of the modem plastics industry. These versatile resin materials were used in a variety of applications, from the synthetic fibers used to make cloth to essential structural components of modern space and aircraft. 

In this brief review we illustrated on selected examples how combinatorial computational chemistry based on first principles quantum theory has made tremendous impact on the development of a variety of new materials including catalysts, semiconductors, ceramics, polymers, functional materials, etc. Since the advent of modem computing resources, first principles calculations were employed to clarify the properties of homogeneous catalysts, bulk solids and surfaces, molecular, cluster or periodic models of active sites. Via dynamic mutual interplay between theory and advanced applications both areas profit and develop towards industrial innovations. Thus combinatorial chemistry and modem technology are inevitably intercoimected in the new era opened by entering 21 century and new millennium. 

In the 1940s to 1950s, Barrer [2], van Amerongen [3], Stem [4], Meares [5] and others laid the foundation of the modem theories of gas permeation. The solution-diffusion model of gas permeation developed then is still the accepted model for gas transport through membranes. However, despite the availability of interesting polymer materials, membrane fabrication technology was not sufficiently advanced at that time to make useful gas separation membrane systems from these polymers. 

The ideas of the well-known physiologist from Bonn, Eduard Pfliiger (1829-1910), seem to predate modem theories he assumed that, under the specific conditions of the primordial Earth, fundamental constituents of protoplasma could have developed from cyanide-type compounds or polymers derived from them (Pfliiger, 1875). 

More modem approaches borrow ideas from the liquid state theory of small molecule fluids to develop a theory for polymers. The most popular of these is the polymer reference interaction site model (PRISM) theory " which is based on the RISM theory of Chandler and Andersen. More recent studies include the Kirkwood hierarchy, the Bom-Green-Yvon hierarchy, and the perturbation density functional theory of Kierlik and Rosinbeig. The latter is based on the thermodynamic perturbation theory of Wertheim " where the polymeric system is composed of very sticky spheres that assemble to form chains. For polymer melts all these liquid state approaches are in quantitative agreement with simulations for the pair correlation functions in short chain fluids. With the exception of the PRISM theory, these liquid state theories are in their infancy, and have not been applied to realistic models of polymers. 

---