Relaxation of Polymer Chains Dissolved in the Liquid Phase of Membranes under a Pressure Gradient. III. Hydrogel Membranes of Poly(vinyl alcohol) and Poly(sodium L-glutamate)

1994 ◽  
Vol 67 (12) ◽  
pp. 3201-3204 ◽  
Author(s):  
Ryotaro Kiyono ◽  
Masayasu Tasaka ◽  
Masanobu Nagura
Keyword(s):  
Liquid Phase ◽  
Pressure Gradient ◽  
Vinyl Alcohol ◽  
Polymer Chains ◽  
Poly Vinyl Alcohol ◽  
Hydrogel Membranes

Protein permeation through poly(vinyl alcohol) hydrogel membranes

Biomaterials ◽  
1994 ◽  
Vol 15 (3) ◽  
pp. 231-238 ◽  
Author(s):  
Krystyna Burczak ◽  
Toshiya Fujisato ◽  
Motoyoshi Hatada ◽  
Yoshito Ikada
Keyword(s):  
Vinyl Alcohol ◽  
Poly Vinyl Alcohol ◽  
Hydrogel Membranes

Relaxation of polymer chains dissolved in the liquid phase of membranes under a pressure gradient

1990 ◽  
Vol 48 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Masayasu Tasaka ◽  
Osamu Sekiguchi ◽  
Munenori Urahama ◽  
Takashi Matsubara ◽  
Ryotaro Kiyono ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Pressure Gradient ◽  
Polymer Chains

Synthesis of nanocomposites: Organoceramics

1992 ◽  
Vol 7 (9) ◽  
pp. 2599-2611 ◽  
Author(s):  
Phillip B. Messersmith ◽  
Samuel I. Stupp
Keyword(s):  
Vinyl Alcohol ◽  
Water Soluble ◽  
Polymer Chains ◽  
Poly Vinyl Alcohol ◽  
Synthetic Approach ◽  
New Materials ◽  
Water Soluble Polymers ◽  
Homogeneous Solutions ◽  
New Processing ◽  
Diffuse Reflectance Infrared

We report here on the synthesis of new materials termed organoceramics in which polymers are molecularly dispersed within inorganic crystalline phases. These nanocomposite materials may not only have unique morphologies and physical properties but may also lead to new processing methods for ceramic-based materials. In organoceramics polymer molecules could opportunistically occupy sites such as grain boundaries or other two-dimensional defects, nanopores, lattice channels, or interlamellar spaces. Our synthetic approach to get macromolecules to those sites is to nucleate and grow inorganic crystals from homogeneous solutions containing the polymer chains as co-solutes. The new materials discussed in this manuscript were synthesized by growing calcium aluminate crystals in the presence of water soluble polymers and were characterized by x-ray diffraction, scanning electron microscopy, elemental analysis, and diffuse reflectance infrared spectroscopy. The macromolecules used in organoceramic synthesis included poly(vinyl alcohol), poly(dimethyldiallyl ammonium chloride), and poly(dibutyl ammonium iodide). We found that the chemistry of polymer repeats can impact on the spatial distribution of the dispersed organic chains and also on the morphology of organoceramic powders. In the case of the poly(vinyl alcohol) organoceramic the polymer is intercalated in “flattened” conformations in Ca2Al(OH)6[X] ·nH2O, thus increasing the distance between ionic layers from 7.9 Å to ∊ 18 Å (X is a monovalent or divalent anion). Such a layered nanocomposite can be formed only by intercalating the poly(vinyl alcohol) during growth of the Ca2Al(OH)6[X] · nH2O crystal. The synthetic pathway is therefore able to overcome large entropic barriers and incorporate significant amounts of polymer in the organoceramic product, in some cases up to 38% by weight. The particles of this nanocomposite are spheroidal aggregates of thin plate crystals whereas the use of a polycationic polymer in the synthesis leads to rod-like particles in which organic chains may reside in channels of the inorganic crystal.

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