Book reviews

AUTOMATIC METHODS OF ANALYSIS by M. Valcárcel and M. D. Luque de Castro, Volume 9 in series Techniques and Instrumentation in Analytical Chemistry, Elsevier Science Publishers, Amsterdam (1988), 560 pages, US$ 131.50

SELF‐DIFFUSION IN ELECTROLYTE SOLUTIONS: A CRITICAL EXAMINATION OF DATA COMPILED FROM THE LITERATURE by R. Mills and V. M. M. Lobo, Volume 36 published in the series Physical Sciences Data, Elsevier, Amsterdam (1988), 354 pages, US$ 134.25     

Towards green membranes: preparation of cellulose acetate ultrafiltration membranes using methyl lactate as a biosolvent

Ultrafiltration membranes were prepared using cellulose acetate (CA) as a polymer, LiCl and CaCl₂ as porogens and methyl-(S)-lactate as a solvent. CA, methyl lactate and the porogens used in this work are obtained from renewable resources; they are biodegradable, non-toxic and non-volatile organic compounds. Flat sheet ultrafiltration membranes were prepared by the phase inversion technique. A molecular weight cut-off between 15 and 35 kDa (polyethylene glycol) and pure water permeability between 13 and 177 litres h^? 1m^? 2 bar^? 1 were obtained. These parameters are in the ideal range for water treatment industry. Improvement of pollutant degree and ecotoxicity of the process was evaluated by ‘green’ metrics by the P (pollutants, persistent and bioaccumulative) and E (ecotoxicity) parameters. Both of these variables were recorded as zero using our method. This study represents a step ahead towards the production of ultrafiltration polymeric membranes by a ‘greener’ process than current methods.     

SPSF共混Tröger’s base超滤膜制备及抗污染性能

以Tröger base （TB）和磺化度为20%的磺化聚砜（SPSF）为共混材料,N-甲基-2-吡咯烷酮（NMP）为溶剂,乙二醇单甲醚（EGM）为致孔剂,去离子水为凝固浴,采用非溶剂致相分离法（NIPS）制备了一种新型的SPSF/TB共混超滤膜,考察了共混比对膜结构、水接触角、孔隙率、水通量、BSA截留率和抗污染性能的影响.结果表明,共混之后原有的中性胺及磺酸反应生成了相应的铵盐及磺酸根,表面接触角得以降低,亲水性增强,水通量增加,显著改善了膜的抗污染能力;此外,SPSF/TB膜结构上变成了梯度海绵孔结构,特别是较大共混比时因有机高分子盐的形成,聚合物交联呈现了独特的网状结构.与纯TB膜相比,SPSF/TB^3~15膜水通量JWC达到274.92~343.21L/（m²·h）（操作压力为0.1MPa）,通量恢复率值（FRR）达到61.11%~67.45%,分别提升了42.88%~78.37%和67.4%~84.8%.在最优条件下,SPSF/TB⁵对废水中的乳化油截留率可达到98.52%以上,循环3次后水通量和FRR分别趋于199.1L/（m²·h）和61.6%.