611. High-polymer solutions. Part I. Osmotic-pressure measurements with poly(vinyl alcohol) membranes

1952 ◽  
pp. 3190 ◽  
Author(s):  
H. T. Hookway ◽  
R. Townsend
Keyword(s):  
Osmotic Pressure ◽  
Vinyl Alcohol ◽  
Polymer Solutions ◽  
Poly Vinyl Alcohol ◽  
Pressure Measurements ◽  
High Polymer

scholarly journals Poly(vinyl alcohol) Physical Hydrogel Nanoparticles, Not Polymer Solutions, Exert Inhibition of Nitric Oxide Synthesis in Cultured Macrophages

2013 ◽  
Vol 14 (5) ◽  
pp. 1687-1695 ◽  
Author(s):  
Sidsel Ø. Andreasen ◽  
Siow-Feng Chong ◽  
Benjamin M. Wohl ◽  
Kenneth N. Goldie ◽  
Alexander N. Zelikin
Keyword(s):  
Nitric Oxide ◽  
Vinyl Alcohol ◽  
Polymer Solutions ◽  
Poly Vinyl Alcohol ◽  
Nitric Oxide Synthesis ◽  
Hydrogel Nanoparticles

scholarly journals Cryostructuring of Polymeric Systems †: Application of Deep Neural Networks for the Classification of Structural Features Peculiar to Macroporous Poly(vinyl alcohol) Cryogels Prepared without and with the Additives of Chaotropes or Kosmotropes

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4480
Author(s):  
Ilya I. Kurochkin ◽  
Ilya N. Kurochkin ◽  
Olga Yu. Kolosova ◽  
Vladimir I. Lozinsky
Keyword(s):  
Neural Networks ◽  
Vinyl Alcohol ◽  
Network Architecture ◽  
Deep Neural Networks ◽  
Polymer Solutions ◽  
Total Porosity ◽  
Structural Features ◽  
Poly Vinyl Alcohol ◽  
Macroporous Structure

Macroporous poly(vinyl alcohol) cryogels (PVACGs) are physical gels formed via cryogenic processing of polymer solutions. The properties of PVACGs depend on many factors: the characteristics and concentration of PVA, the absence or presence of foreign solutes, and the freezing-thawing conditions. These factors also affect the macroporous morphology of PVACGs, their total porosity, pore size and size distribution, etc. In this respect, there is the problem with developing a scientifically-grounded classification of the morphological features inherent in various PVACGs. In this study PVA cryogels have been prepared at different temperatures when the initial polymer solutions contained chaotropic or kosmotropic additives. After the completion of gelation, the rigidity and heat endurance of the resultant PVACGs were evaluated, and their macroporous structure was investigated using optical microscopy. The images obtained were treated mathematically, and deep neural networks were used for the classification of these images. Training and test sets were used for their classification. The results of this classification for the specific deep neural network architecture are presented, and the morphometric parameters of the macroporous structure are discussed. It was found that deep neural networks allow us to reliably classify the type of additive or its absence when using a combined dataset.

Bending Characteristics of Electrical Responsive Poly(vinyl alcohol)/Poly(acrylic acid) Semi-Interpenetrating Polymer Network Hydrogel under DC Electric Field

2009 ◽  
Vol 79-82 ◽  
pp. 1595-1598 ◽  
Author(s):  
Wei Wei Cui ◽  
Li Zhu Liu ◽  
Xing Song Zhu
Keyword(s):  
Acrylic Acid ◽  
Osmotic Pressure ◽  
Vinyl Alcohol ◽  
Polymer Network ◽  
Interpenetrating Polymer Network ◽  
Poly Vinyl Alcohol ◽  
Gradient Theory ◽  
Stimuli Responsive ◽  
Interpenetrating Networks ◽  
Poly Acrylic Acid

Semi-Interpenetrating networks (SIPN) hydrogel composed of poly (acrylic acid) (PAA) and poly (vinyl alcohol) (PVA) was prepared by free radical solution polymerization. The SIPN was characterized by Fourier transform infrared spectroscopy (FTIR). The electric stimuli responsive characteristics were investigated. The hydrogel bent toward the anode initially, altered the bending direction for two times and bent toward the anode ultimately when it was placed in a 0.1 M NaCl aqueous solution under non-contact DC field. For interpreting the special deformation the osmotic pressure curves according to Shiga’ osmotic pressure model were simulated and the pH gradient theory was applied to explain the final direction.

scholarly journals Poly(Vinyl Alcohol) Cryogels Formed from Polymer Solutions in Dimethyl Sulfoxide with Tetramethoxysilane Additives

2019 ◽  
Vol 14 (2) ◽  
pp. 41-50
Author(s):  
I. V. Bakeeva ◽  
M. A. Orlova ◽  
V. I. Lozinsky
Keyword(s):  
Dimethyl Sulfoxide ◽  
Vinyl Alcohol ◽  
Polymer Solutions ◽  
Cryogenic Treatment ◽  
Sol Gel ◽  
Frozen Storage ◽  
Acid Catalyst ◽  
Poly Vinyl Alcohol ◽  
Initial Reaction ◽  
Oh Groups

Organic–inorganic hybrid cryogels of poly(vinyl alcohol) (PVA) containing silica inclusions (SiO2) were obtained and studied. Such inclusions were formed in the course of hydrolytic polycondensation (sol-gel process) of tetramethoxysilane (TMOS) introduced into concentrated polymer solutions in dimethyl sulfoxide (DMSO). PVA concentration in these solutions was 60, 80 or 100 g/L; while the concentration of TMOS was varied in a range of 0.15–0.61 mol/L. The polymer solutions were subjected to the cryogenic treatment at temperatures by 40 °С lower than DMSO crystallization temperature (+18.4°C). The frozen samples were thawed out at a heating rate of 0.03°/min. It is shown that moderate freezing at −21.6 °C, then frozen storage and subsequent thawing of the initial reaction mixture PVA/DMSO/TMOS/acid catalyst resulted in the formation of strong macroporous PVA/SiO2 cryogels. Such cryogel materials are hybrid systems, because the gel-forming polymer and the silica containing moieties belong to the content of the gel phase. The basis of this intermolecular interaction is hydrogen bonding between OH groups of the adjacent chains. This leads to the formation of modified microcrystallinity zones that perform as the nodes of the three-dimensional network of cryogels. The effects of significant increase in their rigidity and heat-resistance with increasing PVA and TMOS concentration in the initial feed were also observed. It was shown that the success of the synthesis of transparent elastic and heat-resistant PVA/SiO2 cryogels depends on the choice of the optimal ratio between the precursors and the combined effect of the liquid (methanol and water) and silicon-containing components on the formation of multiple hydrogen bonds and microcrystallites.

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