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Using Green Solvents to Fabricate Membrane Distillation Membranes
Published in Kang-Jia Lu, Tai-Shung Chung, Membrane Distillation, 2019
Organic solvents are very commonly used in many steps of membrane fabrication. Many of these solvents are toxic and pose threat to human health and the environment, but it is hard to replace them because of their broadly satisfactory properties such as solubility, viscosity, polarity, and boiling points (Figoli et al., 2014; Xing et al., 2014). Common solvents to prepare polyvinylidene fluoride (PVDF) membranes for membrane distillation (MD) are dimethylformamide (DMF), dimethylacetamide (DMAc), and N-methyl-2-pyrrolidone (NMP). For example, Tomaszewska used DMF and DMAc to cast flat sheet membranes with a permeation flux of about 10 kg/m2 h (Tomaszewska, 1996). Hou et al. employed DMAc to fabricate single-layer hollow fiber membranes with a permeation flux of about 20 kg/m2 h (Hou et al., 2009). Wang et al. utilized NMP to produce dual-layer hollow fiber membranes with a permeation flux over 40 kg/m2 h (Wang et al., 2011). However, all these three solvents are very toxic and can cause many diseases. Table 9.1 briefly summarizes their hazard statements and linked diseases (Casarett et al., 2001; Regulation (EC) No. 1272/2008, 2008). In contrast, triethyl phosphate (TEP), for example, is a much safer solvent (Byrne et al., 2016; Capello et al., 2007). It is only harmful when being swallowed. In this case, not only can workers be better protected, the treatment of waste effluent can also be simplified.
Colon Targeted Drug Delivery Systems
Published in Ambikanandan Misra, Aliasgar Shahiwala, In-Vitro and In-Vivo Tools in Drug Delivery Research for Optimum Clinical Outcomes, 2018
In a similar study, Molly et al. (Molly, Woestyne, and Verstraete 1993) developed a five-step multi-chamber reactor (SHIME) to simulate both the small and large intestinal microbial ecosystem. Three polymeric prodrugs of 5-ASA, poly(1-vinyl-2-pyrrolidone-co-maleic anhydride) (PVP-MA), poly(N-(2-hydroxyethyl)-DL-aspartamide) (PHEA), and dextran, were evaluated in the SHIME reactor. Little or no hydrolysis of the three prodrugs was observed in the reactors representing stomach and small intestine. The release of 5-ASA was most pronounced in the reactor simulating caecum and proximal colon. The results also indicated that the extent of drug release in the reactor simulating caecum and proximal colon depends on the nature of polymeric carriers (Schacht et al. 1996).
Health and Safety Information
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Name Peroxyacetic acid -Phellandrene Phenanthrene Phenol 2-Phenoxyethanol Phenyl acetate N-Phenyl-N,N-diethanolamine N-Phenylethanolamine Phenylhydrazine Phenyloxirane 1-Phenyl-1-propanone 1-Phenyl-2-propylamine, ()Phorone Phosphine Phosphorus (white) Phthalic acid Phthalic anhydride -Pinene -Pinene Piperazine 1-Piperazineethanamine 1-Piperazineethanol Piperidine Propanal Propane 1,3-Propanediamine 1,2-Propanediol 1,3-Propanediol Propanenitrile Propanoic acid Propanoic anhydride 1-Propanol 2-Propanol Propanoyl chloride Propargyl alcohol Propene Propyl acetate Propylamine Propylbenzene Propyl butanoate Propylcyclohexane Propylcyclopentane Propylene carbonate Propyl formate Propyl nitrate Propyl propanoate Propyne Pyridine Pyrocatechol Pyrrole Pyrrolidine 2-Pyrrolidone Quinoline Resorcinol Safrole Salicylaldehyde Silane Octadecanoic acid Styrene Succinonitrile Sulfolane -Tartaric acid Terephthalic acid Mol. form. C2H4O3 C10H16 C14H10 C6H6O C8H10O2 C8H8O2 C10H15NO2 C8H11NO C6H8N2 C8H8O C9H10O C9H13N C9H14O H3P P C8H6O4 C8H4O3 C10H16 C10H16 C4H10N2 C6H15N3 C6H14N2O C5H11N C3H6O C3H8 C3H10N2 C3H8O2 C3H8O2 C3H5N C3H6O2 C6H10O3 C3H8O C3H8O C3H5ClO C3H4O C3H6 C5H10O2 C3H9N C9H12 C7H14O2 C9H18 C8H16 C4H6O3 C4H8O2 C3H7NO3 C6H12O2 C3H4 C5H5N C6H6O2 C4H5N C4H9N C4H7NO C9H7N C6H6O2 C10H10O2 C7H6O2 H4Si C18H36O2 C8H8 C4H4N2 C4H8O2S C4H6O6 C8H6O4 tb/ºC 110 177 338.4 181.8 246 195 280 244 194.1 217.4 198 197 -87.75 280.5 dec 285.3 156.3 165.8 148.63 225 259 106.19 48.0 -42.11 139.2 187.3 214.7 97.3 141.5 168 97.04 82.21 80 113 -47.6 101.0 47.21 159.2 144 156.7 130.9 241.6 80.6 110 122.2 -23.2 115.2 246 129.74 86.6 251.2 237.1 280 235 208 -111.9 371 145.3 266 286 300 sp FP/ºC Flam. limits 41 49 171 79 1.8-8.6% 121 80 196 >0.7% 152 88 74 99 <100 85 >1.8% 168 152 33 38 81 93 124 16 -30 -104 24 99 2 52 63 23 12 12 36 13 -37 30 37 IT/ºC VP(25 °C)/kPa 1.93 0.189 0.055 0.001
Investigation of different molecular weight Polyvinylidene Fluoride (PVDF) polymer for the fabrication and performance of braid hollow fiber membranes
Published in Environmental Technology, 2022
Gizem Tuncay, Türker Türken, İsmail Koyuncu
Within the scope of the study, braid reinforced hollow fiber membranes with high permeability and mechanical strength were produced. Low molecular weight PVDF301F polymer and high polymer weight PVDF761A polymer were used for production. Polyvinylpyrrolidone (PVP) was used as the pore-forming polymer. The polymer with a molecular weight of 40,000 Da was used PVP40. Maleic anhydride (MA) was used as crosslinker and N-methyl-2-pyrrolidone (NMP) was used as solvent. Membrane solution was prepared from two different PVDF polymers at a ratio of 1:1 with and without blending and produced. Production was done at the same coagulation bath temperature, air gap distance, and take-up speed. The fluxes of the membranes were examined and compared under three different pressures. The removal efficiencies were investigated by passing BSA through the membranes. To determine the fouling performances of the fabricated membranes, TMP profiles were investigated in the pilot-scale MBR system.
Hydrogen generation from ammonia borane by NiRu nanoparticles catalysts
Published in Inorganic and Nano-Metal Chemistry, 2021
Nickel(II) chloride hexahydrate (NiCl2•6H2O), ruthenium(III) chloride trihydrate (RuCl3.3H2O), ammonia borane (H3NBH3), and poly(N-vinyl-2-pyrrolidone) (PVP-40) were supplied from Sigma-Aldrich. Ethanol was purchased from Merck.