Investigation on surface molecular conformations and pervaporation performance of the poly(vinyl alcohol) (PVA) membrane

Zhang, Wei; Zhang, Zhennan; Wang, Xinping

doi:10.1016/j.jcis.2009.01.058

Cited by 39 publications

(25 citation statements)

References 45 publications

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“…27,[30][31][32] The calculated degrees of crystallinity are listed in Table I. It was evident from the data that the degree of crystallinity of the samples increased with the concentration of the NaOH solution (see Fig.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of novel, highly crystalline poly(vinyl alcohol) microspheres for chemoembolization therapy

Semenzim

Basso

Silva

et al. 2011

J of Applied Polymer Sci

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Biodegradable polymeric microspheres can be used to deliver drugs through controlled rate and targeted processes. The drug is released from the particles by drug leaching or degradation of the polymeric matrix. Crystallinity can play a very important role in the degradation of polymeric matrixes; it can affect the drug-release rate, especially in chemoembolization. Most commercial embolic agents have a low degree of crystallinity, and the correlation between the drug-delivery rate and the degree of crystallinity is not fully understood. This study presents the appropriated synthesis conditions for the preparation of highly crystalline poly(vinyl alcohol) and poly(vinyl alcohol)/poly(vinyl acetate) microspheres and physicochemical characterizations by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, and cross-polarization/magic angle spinning nuclear magnetic resonance.

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Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of novel, highly crystalline poly(vinyl alcohol) microspheres for chemoembolization therapy

Semenzim

Basso

Silva

et al. 2011

J of Applied Polymer Sci

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“…That is, the feed mixture first dissolves in the membrane feed side. Then, the permeates diffuse through the membrane and detach to the downstream side in a vapor state (Cheng et al 2017;Das et al 2011;Hong et al 2011;Rachipudi et al 2011;Xu et al 2017;Zhang et al 2009). Therefore, a PV membrane has a dense selective layer which can mitigate the fouling problem encountered by a typical MD process where the pores of the MD membrane are easily fouled during the separation process.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of high-performance PVA/PAN composite pervaporation membranes crosslinked by PMDA for wastewater desalination

Zhang

Cao

et al. 2018

Pet. Sci.

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The pyromellitic dianhydride (PMDA) crosslinked poly(vinyl alcohol) (PVA) was coated on top of the PAN ultrafiltration membrane to form a PVA/PAN composite PV membranes for wastewater desalination. The composite membranes have high application value in industrial wastewater treatment. By varying the membrane fabrication parameters including the weight percent (wt%) of the PMDA, the crosslink temperature and duration, membrane with the best desalination performance was obtained. The composite membrane with a 2-lm-thick PVA selective layer containing 20 wt% of PMDA and being crosslinked at 100°C for 2 h showed the highest NaCl rejection of 99.98% with a water flux of 32.26 L/(m 2 h) at 70°C using the 35,000 ppm NaCl aqueous solution as feed. FTIR spectroscopy, wide-angle X-ray diffraction, thermogravimetric analysis and scanning electron microscope have been used to characterize the structures and properties of both the crosslinked PVA dense films and PVA/PAN composite membranes. The effects of the concentrations of PMDA, the crosslinking time and temperature to the membrane water contact angle, swelling degree, salt rejection and water flux were systematically studied.

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“…fr H ∆ es el cambio en el calor de fusión para el PVA de referencia (cristalinidad 100%) y normalmente se toma como 167 J/g [19].…”

Section: Transiciones Térmicasunclassified

Membranas Compuestas: propiedades superficiales y estabilidad térmica

Carlo

Habert

2018

Matéria (Rio J.)

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RESUMEN Las membranas compuestas fueron preparadas con poli(alcohol vinílico) entrecruzado sobre membranas porosas de polietersulfona por el proceso de recubrimiento. Las membranas de PES fueron expuestas al plasma de aire con el propósito de modificar las propiedades superficiales. La capa de recubrimiento se preparó usando una matriz polimérica con un agente entrecruzamiento. Las propiedades físico-químicas se han estudiado por espectroscopía de infrarrojo con reflectancia total atenuada horizontal (FTIR / HATR) y medidas de ángulo de contacto. La estabilidad térmica y propiedades de transición de fases fueron investigadas por análisis térmico gravimétrico (TGA) y calorimetría diferencial de barrido (DSC). El poli(alcohol vinílico) es un polímero soluble en agua debe ser entrecruzado por reacciones de modificación con un agente de entrecruzamiento para formar una membrana estable con buenas propiedades mecánicas en pervaporación. Se utilizó PVA como polímero denso con ácido maléico como agente de entrecruzamiento. Los espectros de infrarrojo revelaron la naturaleza química de la superficie. Las medidas de ángulo de contacto evaluaron los cambios en las propiedades hidrofílicas. El tratamiento con plasma de aire causó una eficaz modificación de la superficie del soporte. El mecanismo responsable por la mejora en la mojabilidad fue la funcionalización superficial por inserción de grupos polares. La introducción de ácido maléico en la cadena del polímero aumentó la región amorfa de la membrana. El PVA es un polímero semi-cristalino que exhibe ambos una temperatura de transición vítrea (Tg) y una isoterma de fusión (Tm), como fue evidenciado en los termogramas de DSC. Se mejoraron significativamente las propiedades térmicas de las membranas compuestas, ambas, la temperatura de descomposición y el peso residual aumentaron.

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Investigation on surface molecular conformations and pervaporation performance of the poly(vinyl alcohol) (PVA) membrane

Cited by 39 publications

References 45 publications

Synthesis and characterization of novel, highly crystalline poly(vinyl alcohol) microspheres for chemoembolization therapy

Synthesis and characterization of novel, highly crystalline poly(vinyl alcohol) microspheres for chemoembolization therapy

Fabrication of high-performance PVA/PAN composite pervaporation membranes crosslinked by PMDA for wastewater desalination

Membranas Compuestas: propiedades superficiales y estabilidad térmica

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