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( Shivshankar Chaudhari ),이남규,권용성,문명준,남승은,박유인,손민영 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0
The membranes from hydrophilic polymer (PVA) and in organic cross linker tetra ethyl orthosilicate (TEOS) called Silicon- PVA hybrid membrane were prepared and employed in the pervaporation removal of water from the azeotropic water/isopropyl alcohol/ECH feed mixtures. At the final state of epoxy resin production process, the ECH/IPA/water remains along with final product, and the recovery of the ECH/IPA from the ternary mixture by the vacuum distillation is a very complex and energy consuming process. Therefore the Si-PVA hybrid membrane was used to pervaporative dehydration of water/isopropyl alcohol/ECH mixtures. FTIR characterization was technique was used to confirm the PVA and TEOS crosslinking reaction. In the pervaporation output with increased of the TEOS content in the PVA-TEOS hybrid membrane, the permeation flux was decreased from the 0.14 kg/m2h to 0.05 kg/m2h and separation factor remarkably increased from 2099 to 13320 were observed.
( Chaudhari Shivshankar Subhash ),손민영,남승은,박유인 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1
In this study Poly (vinyl alcohol) (PVA)-tetraethyl orthosilicate organicinorganic hybrid membrane has prepared and modified the membrane surface by layer-by-layer deposition of a PVAm/silicotungstic acid polyelectrolyte for the pervaporation dehydration of ECH/IPA/water mixtures. Membrane characterization using FTIR, FE-SEM, and SEMEDS, XPS and TGA measurements was carried out. In pervaporation experiments at 30 °C, the flux decreased 0.14 to 0.05 kg m-2 h-1 and separation factor increased from and 2099 to 13320 with TEOS addition in the PVA membrane was observed. And for the layer by layer deposition on PVA-TEOS (4) membranes flux increased and separation factor decreased from 0.14 to 0.28 kg m-2 h and 2099 to 416 with the number of layer of deposition were observed. The pervaporation output of the PVA-TEOS and layer by layer PVA-TEOS membranes reflects the both membranes have excellent ability in epichlorohydrin, isopropanol and water ternary mixture pervaporation dehydration.
Shivshankar Chaudhari,YongSung Kwon,ChiYoung Park,MyungJun Moon,MinYoung Shon,SeungEun Nam,YouIn Park 한국막학회 2017 한국막학회 총회 및 학술발표회 Vol.2017 No.11
Blended membranes of hydrophilic polymers poly (vinyl alcohol) (PVA) and poly(vinyl amine) (PVAm) were prepared and crosslinked with glutaraldehyde. The characterization of membranes were done by using FTIR, XRD, DSC, SEM and swelling study. MB1.5 membrane was the best one in all since it exhibited higher separation index. By using blend membrane (MB1.5), the flux through a 65-mm film increased from 0.01 to 0.47 kg/m2h at an acetonitrile/water feed ratio between 20/80 and 5/95 w/w at 30°C while separation factor increased from the 5055 to 100.84 attributed to the higher hydrophilicity of blend membranes. On comparison of pervaporation data with water-acetonitrile vapor-liquid equilibrium data it was observed that the membrane acted as third phase to effectively break the azeotropes.
Shivshankar Chaudhari,YongSung Kwon,MinYoung Shon,SeungEun Nam,You-In Park 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.81 No.-
Conventional distillation failed to separate a ternary azeotropic mixture of ECH, IPA and water (50/30/20 w/w, %) exist in the epoxy resin manufacturing process. Thus, we prepared a PVA-tetraethylorthosilicate organic–inorganic hybrid membrane and modified the membrane by layer-by-layerdeposition of a PVAm/silicotungstic acid polyelectrolyte for the pervaporation (PV) dehydration of ECH/IPA/water mixtures. In PV experiments at 30 C, theflux decreased from 0.14 to 0.05 kg m 2 h 1 andseparation factor increased from and 2099 to 13,320 with TEOS addition in the PVA membrane wasobserved. And for the layer by layer deposition on PVA-TEOS (4) membranesflux increased andseparation factor decreased from 0.14 to 0.28 kg m 2 h 1 and 2099 to 416 with the number of layer ofdeposition were observed respectively. On varying the feed water content from 20 to 10 wt. %, thepervaporationflux at 30 C decreased from 0.22 to 0.0066 kg m 2 h 1 and the separation factor increasedfrom 1061 to 9094 was observed. By applying the Arrhenius equation, permeation activation energies ofECH and IPA (97.42 and 111.96 kJ mol-1, respectively) are higher than that of water (40.88 kJ mol 1) werereported for the layer by layer membrane.
Shivshankar Chaudhari,권용성,문명준,손민영,박유인,송혜림,장봉준,남승은 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.10
The preparation of a water-selective membrane from the crosslinking of high molecular weight poly(vinyl alcohol) (PVA) with tartaric acid is reported. The resulting membrane was characterized by IR spectroscopy, swelling studies, differential scanning calorimetry, and contact angle testing, and was finally applied in the pervaporation. The performance of the membrane was evaluated in relation to the mixing ratio, changes in feed concentration, and changes in operating temperature. An optimum mixing ratio of 80:20 (wt %) of PVA to tartaric acid was determined, giving a flux range from 0.0072 to 0.095 kg/m2h and a separation factor of 41.5–707.6 at 40–60 °C and 80–90 wt % aqueous acetic acid feed solution. From an Arrhenius type of relationship, it was determined that flux varies exponentially with temperature. The activation energy was calculated for the permeation of each of component of the mixture, with a higher activation energy being observed for acetic acid than for water. From the separation index, it could be concluded that the membrane has good selectivity toward water and exhibits better performance at higher acetic acid concentrations.
Shivshankar Chaudhari,권용성,손민영 대한화학회 2019 Bulletin of the Korean Chemical Society Vol.40 No.3
Acetonitrile and water forms an azeotropic mixture having a boiling point of 76.5 °C and containing approximately 82.2 wt % acetonitrile under atmospheric pressure. Accordingly for their separation, heterogeneous distillation, extractive distillation, and solvent extraction have been used. The recovery of solvent and solute from the extract phase can usually be done by additional distillation processes, which ultimately lead to a less economical and energy intensive pathway. The hydrophilic polymers, poly(vinyl alcohol) and poly(vinyl amine) were used to prepared blended membrane and crosslinked them using glutaraldehyde as crosslinking agent. The FTIR, XRD, DSC, SEM, and swelling studies techniques were used to characterize all the blended membranes and applied for pervaporation separation of water/acetonitrile feed mixtures. Comparison of pervaporation data with water?acetonitrile vapor?liquid equilibrium data confirmed that the membrane acted as a third phase to effectively break azeotropes.
Shivshankar Chaudhari,권용성,문명준,손민영,남승은,박유인 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.12
The in situ generation of silver nanoparticles in a poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) polymer matrix in the absence of any additional reducing agent is reported and tends to the membrane fabrication using solution-casting. Its effect on the separation of a water/acetic acid mixture by pervaporation is described. The results of UV spectroscopy, scanning electron microscopy, and scanning electron microscopy/energy-dispersive X-ray spectroscopy analyses showed that the silver nanoparticles were successfully prepared and well dispersed in the polymer matrix. The increased hydrophilicity of the PVA/PAA membrane due to the presence of silver nanoparticles was confirmed by Fourier transform infrared spectroscopy, contact angle measurements, and membrane absorption studies. Pervaporation data for composite membranes showed a three-fold increase in the flux value, while the initially decreased separation factor subsequently showed a constant value. Overall, the pervaporation data suggested that the presence of silver nanoparticles benefited the dehydration process.