Copolymer block, “tunable

HE1 He, C., Zhao, C., Chen, X., Guo, Z., Zhtrang, X., and Jing, X., Novel pH- and temperature-responsive block copolymers with tunable pH-responsive range, Macromol. Rapid Commun., 29, 490, 2008. 

Y. Kotsuchibashi, M. Ebara, K. Yamamoto, and T. Aoyagi, On-off switching of dynam-ically controllable self-assembly formation of double-responsive block copolymers with tunable LGSTs,/. Polym. Sci. Part A Polym. Chem., 48, 4393-4399, 2010. 

Soliman GM, Winnik EM (2008) Enhancement of hydrophilic drug loading and release characteristics through micellization with new carboxymethyldextran-PEG block copolymers of tunable charge density. Int J Pharm 356 248-258... 

Hydrophilic surfaces, 1 584—585 Hydrophilic/tunably hydrophilic/ hydrophobic block copolymers, 20 485-487 Hydrophilite, 5 785t Hydrophobic additives, in paper manufacture, 18 113 Hydrophobic alkoxy silanes, as silylating agents, 22 697... 

The use of block copolymers to form a variety of different nanosized periodic patterns continues to be an active area of research. Whether in bulk, thin film, or solution micelle states, block copolymers present seemingly unlimited opportunities for fabricating and patterning nanostructures. The wealth of microstructures and the tunability of structural dimensions make them a favorable choice for scientists in a variety of research fields. As reviewed here, they can function as nano devices themselves, or act as templates or scaffolds for the fabrication of functional nanopatterns composed of almost all types of materials. However, there are still two obvious areas which require more work control of the long-range 3D nanostructure via more user-friendly processes and the identification of new materials with different functional properties. 

Binder WH, Bemstorff S, Kluger C, Petraru L, Kunz MJ. Tunable materials from hydrogen-bonded pseudo block copolymers. Adv Mater 2005 17 2824-2828. 

Keywords Hydrogen bonding Polymers Block copolymers Self-assembly Tunability Responsivity... 

Urbas, A., Sharp, R., Fink, Y. et al.. Tunable block copolymer/homopolymer photonic crystals, Adv. Mater., 12, 812, 2000. 

That crosslinking has indeed occurred is confirmed by the very existence of aggregates at 25 °C, as in its absence the diblock copolymers are completely soluble at this temperature. Tunability of the solubility of the PMEMA block in water arises from the fact that its lower critical solution temperature (LCST) lies between 25 and 60 °C. This reversible hydration of the core could be a very useful feature to trigger release of occluded guest molecules from the core interior. More recently, utilizing a similar methodology, zwitterionic shell-crosslinked systems have also been prepared wherein the core and shell domains contain amine and carboxylic acid groups, respectively, or vice versa. Such systems exhibit an isoelectric point, at a pH wherein the crosslinked micelles ( 40 nm) become electrically neutral and precipitate out in water addition of acid or base causes complete redissolution of these nanospheres [58]. 

The synthesis of polypeptide hybrid block copolymers is an area that has been under study for three decades. Initially, this field suffered from limitations in the synthesis of the polypeptide components that required excessive sample purification and fractionation to obtain well-defined copolymers. In recent years, vast improvements in NCA polymerizations now allow the synthesis of hybrid block copolymers of controlled dimensions (molecular weight, sequence, composition, and molecular weight distribution). Such well-defined materials will greatly assist in the identification of new self-assembled structures possible using ordered polypeptide segments, as well as yield new materials with a wide range of tunable properties. 

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