Nonbiological polymers

Time scales for various motions within biopolymers (upper) and nonbiological polymers (lower). The year scale at the bottom shows estimates of when each such process might be accessible to brute force molecular simulation on supercomputers, assuming that parallel processing capability on supercomputers increases by about a factor of 1,000 every 10 years (i.e., one order of magnitude more than Moore s law) and neglecting new approaches or breakthroughs. Reprinted with permission from H.S. Chan and K. A. Dill. Physics Today, 46, 2, 24, (1993). 

Earlier studies with synthetic nonbiological polymers, e.g. vinyl polymers, failed to demonstrate antibody formation in animals This apparent lack of immuno-... 

We have seen how polymers can be broadly classified into categories of natural or biological polymers and synthetic or nonbiological polymers. It is also possible to use other classifications such as polymer structure, or processibility. 

DNA, polypeptides (such as PBG mentioned above), and polysaccharides (such as xanthan) and many other biological and nonbiological polymers have a definite handedness due to the chiral centers. Rod-like long molecules of these materials in water solutions often crystallize into a hexagonal columnar phase so that the cross-section normal to the rods reveals a triangular lattice. Since the polymers are chiral, close hexagonal packing competes with the tendency to twist [25], [26]. Macroscopic twist can proliferate by... 

Industrial polymers. Nonbiological polymers pose the same problems as biopolymers. And more commonly they are recorded with a subscripted notation (e.g., 3). 

Solid-phase organic syntheses of nonbiological oligomers have advantages over solution-phase methods with respect to sequence control, ease of purification, and speed. The products can be well-defined oligomers that are unlike the mixtures usually obtained in classical polymer syntheses. This chapter explores some recent developments in this area, with an emphasis on our own work at the University of Illinois. 

Entropic ordering also appears in nonbiological settings, especially in the ways polymer molecules clump together. For example, polymers added to. paint to improve the flow characteristics of the paint actually caused it to coagulate because of depletion forces. 

Both in biological and nonbiological macromolecules the intramolecular folding process is determined by a combination of primary structure and noncovalent directional and nondirectional interactions. Most recently, combinations of various noncovalent interactions were also used to self-assem-ble supramolecular polymers in which the repeat units are interconnected via noncovalent rather than covalent bonds. The field of supramolecular polymers is reviewed by Brunsveld, Folmer, Meijer, and Sijbesma. 

For the quantitative assays of degradation, films were cast in the bottom of 25 x 125 mm glass tubes and rotated overnight for solvent evaporation. BMS (5 ml.) and a 0.1 ml inoculum were added aseptically and the tubes incubated at 25 C for one month. Controls for stability of the polymer to nonbiological hydrolysis with incubation and viability of the inoculum were included. 

Polymersomes are polymer-based bilayer vesicles, also termed as nanometer-sized bags by scientists. The bilayer structure displayed is similar to liposomes and niosomes as shown in Figure 48.7. They can be considered as liposomes but of nonbiological origin. Amphiphilic block copolymers can form various vesicular architectures in solution. They can have different morphologies such as uniform common vesicles, large polydisperse vesicles, entrapped vesicles, or hollow concentric vesicles. ... 

Polymers can be categorized by a number of methods. One technique is to separate them broadly into classifications of natural, or biological, polymers and nonbiological, or synthetic, materials. Whereas synthetic polymers are of fairly recent vintage, natural polymers go back into prehistory. Cellulose, the chief component of plant cell walls, and protein, an essential component of all living cells, are both polymers. Hence, plants and animals are in large measure polymeric in nature. 

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