Nanocomposite membranes consisting of poly(vinyl chloride) graft copolymer and surface-modified silica nanoparticles

Abstract

A graft copolymer of poly(vinyl chloride)-graft-poly(oxyethylene methacrylate) (PVC-g-POEM) was synthesized via atom transfer radical polymerization (ATRP), and fumed silica (SiO 2 ) nanoparticles were modified by grafting POEM via a three-step synthetic approach. The resultant graft copolymer and modified SiO 2 nanoparticles were solution blended to prepare PVC-g-POEM/SiO 2 -POEM nanocomposite membranes. Uniform distribution of SiO 2 -POEM nanoparticles in the membranes and microphase-separated morphology were confirmed by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). X-ray diffraction (XRD) analysis revealed increased randomness in the amorphous phase of PVC-g-POEM and continuous decrease in the interchain d-spacing with increased SiO 2 -POEM content, indicating a more closely packed nanocomposite membrane structure. The mechanical properties of PVC-g-POEM/SiO 2 -POEM membranes were superior to those of PVC-g-POEM, resulting from strong interfacial interactions in the membranes due to the segregation and entanglement of the POEM chains. In addition, the permeation performances of the PVC-g-POEM/SiO 2 -POEM nanocomposite membranes were somewhat better than those of PVC-g-POEM, which showed excellent CO 2 /N 2 and CO 2 /H 2 separation capabilities. For example, the CO 2 permeability and CO 2 /N 2 selectivity of PVC-g-POEM/SiO 2 -POEM (2%) at 35 o C were 200 Barrer and 43, respectively. Thus, we successfully prepared membranes that deliver high permeation properties, as well as good mechanical properties.

Well-Organized Meso-Macroporous TiO2/SiO2Film Derived from Amphiphilic Rubbery Comb Copolymer

“…Successful synthesis of PDMS- g -PEOM comb copolymer was confirmed by FT-IR spectroscopy as shown in Figure a. The presence of methacrylate in POEM with a molecular weight of 500 g/mol was confirmed by the sharp peaks at 1717 and 1637 cm –1 caused by the stretching vibration of the carbonyl group (-CO) in the ester and stretching unsaturated double bond (-CC), respectively . However, the presence of methacrylate in PDMS-mMA with a molecular weight of 10000 g/mol was not clearly observed due to the much lower concentration of terminal methacrylate groups than repeating units of PDMS.…”

“…The presence of methacrylate in POEM with a molecular weight of 500 g/mol was confirmed by the sharp peaks at 1717 and 1637 cm −1 caused by the stretching vibration of the carbonyl group (-CO) in the ester and stretching unsaturated double bond (-CC), respectively. 23 However, the presence of methacrylate in PDMS-mMA with a molecular weight of 10000 g/mol was not clearly observed due to the much lower concentration of terminal methacrylate groups than repeating units of PDMS. The peaks of PDMS-mMA at 1280 and 790 cm −1 are due to symmetric CH 3 deformation and Si(CH 3 ) 2 rocking, respectively.…”

Universal Polymeric-to-Colloidal Transition in Melts of Hairy Nanoparticles

“…In the past few years, GNPs were proposed as promising candidates for gas separation membranes. − Membranes of self-suspended poly­(methyl acrylate)-grafted silica nanoparticles exhibited elevated gas permeability with respect to the corresponding linear polymer chains . The effectiveness of these membranes depended on the molar mass of the tethered chains in a nonmonotonic way.…”

Application of SiO2 nanoparticles with double layer coverage consist of citric acid and l(+)-ascorbic acid for the production of poly(vinyl chloride)/SiO2 nanocomposite films with enhanced optical and thermal properties

“…For instance, Zhu et al find that addition of nanosilica into PVC matrix improves the mechanical properties of the NCs greatly [15]. Ahn et al reported that introduction of organically modified SiO 2 NPs to PVC matrix caused excellent mechanical properties for the resulting NCs [16].…”