Abstract

Results are presented from investigating active and drainage layers of composite films (membranes) UPM-50 and UPM-100 before and after exposure to transmembrane pressure by means of IR spectra of reflection, X-ray scattering, and raster electron microscopy. It is found that changes in the IR spectrum of the working sample are caused by the destruction of weak bonds of C=O···H–N amide fragments of the polysulfonamide film. A drop in (C=O) vibration frequency ν by Δν = 20 cm⁻¹ indicates redistribution of the electron density between C=O-groups and benzene rings as a result of the inductive effect of coupling, which results in the formation of charged functional groups CO⁻. The presence of CO^– groups fragments a new supramolecular structure whose stability due to the dipole–dipole interaction of carbonyl anions. X-ray scattering of the initial and working samples in the 10°–35° range of angles 2θ is determined by three intense reflections at angles 2θ ~ 17.23°, 22.24°, 25.41° from crystallographic planes ((010), (100), and (110)) corresponding to the crystalline structure of lavsan (polyethylene terephthalate). A comparative analysis of the reduced intensities of reflections from crystallographic planes (010), (100) and the sizes of lamellas indicates that transmembrane pressure initiates conformational rearrangement of crystallites with crystallographic axis b oriented parallel to the film plane.

中文翻译：

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跨膜压力对复合膜UPM-50和UPM-100的活性层和排水层结构和输运性能变化的影响分析

摘要

通过反射，X射线散射和光栅电子显微镜的红外光谱研究了跨膜压力暴露前后的复合膜（膜）UPM-50和UPM-100的活性和排水层的结果。发现工作样品的红外光谱变化是由聚磺酰胺膜的C = O···H–N酰胺片段的弱键破坏引起的。（C = O）振动频率ν下降Δν= 20 cm ^-1表示由于耦合的感应效应，C = O-基团和苯环之间电子密度的重新分布，这导致形成电荷官能团CO ^- 。CO的存在^-这些基团使新的超分子结构破碎，其稳定性归因于羰基阴离子的偶极-偶极相互作用。初始样品和工作样品在2θ的10°-35°范围内的X射线散射是由三个强反射从晶体学平面（（010），（100）分别在2θ〜17.23°，22.24°，25.41°处确定的（110））和lavsan（聚对苯二甲酸乙二酯）的晶体结构相对应。对晶体平面（010），（100）的反射强度降低和薄片尺寸的比较分析表明，跨膜压力可引发晶体轴b平行于薄膜平面的晶体构象重排 。