吸收法处理挥发性有机废气的关键是表面活性剂的选择.选取聚乙二醇水溶液处理甲苯废气为研究对象,测定了4种聚乙二醇水溶液的临界胶束浓度及其对甲苯的增溶作用,并在填料塔中探究了吸收剂中聚乙二醇浓度、进口气体中甲苯浓度和液气比对甲苯去除率的影响.结果表明,水溶液中聚乙二醇浓度达到1倍临界胶束浓度时,其对甲苯有显著的增溶作用和去除效果,且甲苯去除率随着增溶量的增加而增大,两者呈正相关.因此,结合临界胶束浓度和增溶量的测定可用于表面活性剂的初步筛选.优选聚乙二醇-600水溶液作为吸收剂,在空气流量300 m L/min,液体喷淋量55 m L/min,进口气体中甲苯浓度800 mg/m3,温度25℃条件下,浓度为1倍临界胶束浓度的聚乙二醇-600水溶液对甲苯的去除率达到83%;且随着吸收剂浓度、进口气体中甲苯浓度的增大,去除率增加,在填料吸收塔中存在最优的液体喷淋量.
Supercritical（SC） CO2 anti-solvent induced polymer epitaxy（SAIPE） method was used to help prepare nanohybrid carbon nanotubes（CNTs） wrapped with polyvinyl alcohol（PVA） nanocrystals.With the variation of a series of experimental conditions or peripheral effects,such as PVA concentration,CNTs concentration,and SC CO2 pressure,the optimal experimental variables for PVA-nanocrystals growing on CNTs have been found.The adsorption of polymer on CNTs via multiple weak molecular interactions has been studied by Fourier transform infrared（FTIR） spectroscopy and Raman spectroscopy.The mechanism about the formation of PVA nanocrystals on CNTs can be suggested through the experimental phenomena.These CNTs wrapped with PVA nanocrystals can be directly used as nanofillers to fabricate PVA composite fibers reinforced with CNTs by electrospinning.
