Bioinspired Poly(vinyl alcohol) Film Actuator Powered by Water Evaporation under Ambient Conditions

Proton conducting solid polymer electrolyte films, which are composed of diazanium hydrogen phosphate (DAHP) and poly(vinyl alcohol) (PVA), were prepared by a solution casting method. The prepared films were characterized by ultraviolet-visible, X-ray diffraction, and differential scanning calorimetry. The optical activation energy and band gap increases with increase in DAHP content in PVA. The direct current (DC) and alternating current (AC) conductivity studies have been carried out using an impedance analyzer. The sample containing 15 wt% DAHP shows highest AC conductivity of the order of 10−4 S cm−1 and DC conductivity about 4.27 × 10−7 S cm−1 at ambient conditions. The crystallinity has decreased and glass transition temperature ( T g) has increased with increase in DAHP content. The Williams–Landel–Ferry and Vogel–Fulcher–Tamman equations were used to calculate dynamic fragility ( m) and apparent activation energy ( E g) from T g values. The Rice and Roth model was successfully applied to determine the transport parameters for DAHP/PVA electrolytes. This article mainly focused on understanding the contribution of different parameters to conductivity phenomenon in solid polymer electrolytes.

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Physically Crosslinked Hydrogels Based on Poly (Vinyl Alcohol) and Fish Gelatin for Wound Dressing Application: Fabrication and Characterization

Polymers ◽

10.3390/polym12081729 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1729

Author(s):

Teng Ren ◽

Jing Gan ◽

Liping Zhou ◽

Hao Chen

Keyword(s):

Salicylic Acid ◽

Vinyl Alcohol ◽

Wound Dressing ◽

Evaporation Rate ◽

Composite Hydrogel ◽

Fickian Diffusion ◽

Water Evaporation ◽

Poly Vinyl Alcohol ◽

Dissolution Behavior ◽

Fish Gelatin

We developed the interpenetrating double network composite hydrogel based on poly (vinyl alcohol) (PVA) and fish gelatin (FG) via thermal treatment and repeated freeze-thawing. A function of salicylic acid was incorporated into the hydrogel to improve its antibacterial properties. The color values, water contents, water evaporation rate, and swelling behavior were investigated. The drug-loading performance of the composite hydrogel was demonstrated by loading salicylic acid in various hydrogel systems. Moreover, the cumulative dissolution percentage of salicylic acid and the antibacterial activity of composite hydrogel were carried out. The results revealed that as FG concentration increased from 0% to 3.75% (w/v), gels changed from white to slight yellow and the swelling ratio increased from 54% to 83% (within 8 h). The presence of FG decreased the water content of gels which ranged from 86% to 89% and also decreased water evaporation rate. All gels presented the swelling index within 0.5–1.0, indicating a non-Fickian diffusion mechanism. The drug sustained dissolution behavior of pure PVA and composite hydrogel showed the same trend. Besides, the presence of the obvious bacteriostatic zones means that drug-loaded composite hydrogels have an effective antibacterial property. These results demonstrated that PVA/FG-based interpenetrating hydrogel is an appropriate biomaterial for drug-carrying wound dressing application.

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Solid-phase esterification between poly(vinyl alcohol) and malonic acid and its function in toughening hydrogels

Polymer Chemistry ◽

10.1039/d0py00023j ◽

2020 ◽

Vol 11 (29) ◽

pp. 4787-4797 ◽

Cited By ~ 3

Author(s):

Tianqi Liu ◽

Xin Peng ◽

Yuanyuan Chen ◽

Jianan Zhang ◽

Chen Jiao ◽

...

Keyword(s):

Malonic Acid ◽

Vinyl Alcohol ◽

Solid Phase ◽

Poly Vinyl Alcohol ◽

Ambient Conditions ◽

Drying Treatment ◽

Esterification Reactions

Solid-phase esterification reactions occur in the poly(vinyl alcohol)-malonic acid (PVA-MA) hydrogel by a simple drying treatment without using any catalyst under ambient conditions, which largely strengthen the hydrogel.

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