Poly(vinyl alcohol)/chitosan blend membranes for pervaporation of benzene/cyclohexane mixtures

Abstract

ABSTRACT:Poly(vinyl alcohol)/chitosan (PVA/CS) blend membranes were prepared by mixing the two polymeric homogeneous solutions. The interaction between PVA and chitosan arising from hydrogen bond was analyzed through intrinsic viscosity determination and Fourier transform infrared (FTIR) spectra, and there existed an incompatibility region in the blend membranes when chitosan content was 50 wt %. X-ray diffraction (XRD) showed that the crystalline structure of PVA and chitosan was disrupted through blending. The incompatibility of two polymers and disrupted crystalline structure led to a less compact structure. The blend membranes were used to pervaporative separation of benzene/cyclohexane (Bz/Chx) mixtures. The effects of chitosan content in blend membranes, weight fraction of benzene in feed, and operating temperature on separation performance of Bz/Chx mixtures were investigated. Compared with pure PVA and pure chitosan membranes, blend membranes showed much higher permeation flux and slightly higher benzene permselectivity. As the weight fraction of benzene in feed increased, separation factor decreased but total permeation flux increased. And it was observed that total permeation flux increased and separation factor decreased with increasing operating temperature. The total permeation flux of blend membrane with 50 wt % chitosan was 51.41 g/(m 2 h) and separation factor was 49.9 for Bz/Chx mixtures with 50 wt % of benzene at 323 K.

Evaluating the potential of chitosan/poly(vinyl alcohol) membranes as alternative carrier material for proliferation of Vero cells

“…Previous reports suggested changes in characteristic spectra peaks due to the reflection of the physical blends and chemical interactions when two or more polymers are mixed (29,30). Results have suggested the miscibility between CS and PVA and may be attributed to the formation of intermolecular hydrogen bonds between the amino and hydroxyl groups of CS and the hydroxyl groups of PVA (26).…”

“…The FTIR spectrum of the PVA membrane ( Figure 1D) showed characteristic bands of O-H stretching at 3340 cm -1 (25). The FTIR spectra of the blend membrane ( Figure 1B) showed chemical interactions between CS and PVA polymer, with the OH stretching band of PVA near 3340 cm -1 broadened and shifted towards higher frequency regions (26). The band at 1570 cm -1 of N-H bending shifted to a higher wave number (10 cm -1 higher than the CS membrane) in the CS/PVA blend.…”

Pervaporation dehydration of ethylene glycol with chitosan–poly(vinyl alcohol) blend membranes: Effect of CS–PVA blending ratios☆

“…CS-PVA blend membranes have been reported to have good mechanical strength in addition to good membrane performance characteristics for pervaporation separation [11][12][13][14][15][16][17][18]. Lu et al [17] found that the permeation flux was dramatically increased (while selectivity was increased only slightly) through blending CS with PVA for benzene/cyclohexane mixtures. The improved PV separation performance was reported by different researchers over a wide range (10-80 wt%) of CS in the blend [14,18].…”

“…Chitosan, a natural hydrophilic polymer, with good chemical resistance, biodegradability, and membrane-forming property, is commonly used to prepare hydrophilic blend membranes [8][9][10]. CS-PVA blend membranes have been reported to have good mechanical strength in addition to good membrane performance characteristics for pervaporation separation [11][12][13][14][15][16][17][18]. Lu et al [17] found that the permeation flux was dramatically increased (while selectivity was increased only slightly) through blending CS with PVA for benzene/cyclohexane mixtures.…”

One pot blending of biopolymer‐TiO2 composite membranes with enhanced mechanical strength

“…[12][13][14][15] Among the modification methods, polymer blending is simple and effective for providing satisfactory polymeric materials. [16][17][18][19][20] It is known that blending proves to be an efficient way to achieve combined properties of individual polymers. 21 Cellulose acetate (CA) is commonly used as membrane material because of its good toughness, high biocompatibility, moderate chlorine resistance, superior film-forming ability, and relatively low cost.…”