Guoke Zhao,Tian Zhong,Xinkai Li,Hao Yu,Guoyuan Pan,Yang Zhang,Yiqun Liu
Scholarly discourse surrounding the thin film composite organic solvent nanofiltration (TFC OSN) membrane field has largely been dominated by focusing on the optimization of the selective layer. However, this often leaves the porous support layer, with its innate solvent resistance, cost-effectiveness, and superior permeability, in the shadows. This study presents a novel OSN membrane utilizing a polyethylene (PE) battery separator as the porous substrate. The structural affinity between ethylene-vinyl alcohol and PE facilitates efficient hydrophilic modification, which allows for uniform and compact polyamide selective layer formation through interfacial polymerization. The HPE-NF-1.0 membrane exhibits rejections of 99.5 %, 96.7 %, 100 %, and 97.2 % for Methyl Orange, Rhodamine B, Congo red, and Rose Bengal, respectively. It also shows a solvent flux of 52.5 LMH in methanol and robust resistance against alcoholic solvents and DMF. Using PE as the porous substrate, we bypass intricate and time-demanding cross-linking processes and complex pore-preservation post-treatments, providing a simplified strategy for TFC OSN membrane fabrication.
Fusheng Pan,Weixiong Guo,Yanlei Su,Niaz Ali Khan,Hao Yang,Zhongyi Jiang
Covalent organic frameworks (COFs) are emerging as crystalline porous materials for advanced membranes, due to their regular pore structures and high porosity. The fabrication of defect-free ultrathin COFs membranes is still very challenging, since the poor COF-substrate affinity hampers the nucleation of COF crystallites. In this work, a facile direct growth method was developed to deposit continuous imine-based COF layer (TpPa-1, synthesized by the Schiff-base reactions of 1,3,5-triformylphloroglucinol (Tp) with p-phenylenediamine (Pa-1)). Aldehydes groups were firstly immobilized on polyacrylonitrile (PAN) porous substrate as the nucleation sites to promote the growth of continuous TpPa-1 layer via a good COF-to-substrate adhesion. Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and X-ray diffractometer (XRD) confirmed the formation of COF layer. The TpPa-1/HPAN membrane exhibited high water flux of 418.5 L/(m 2 h MPa) under the operation pressure of 0.1 MPa and excellent dyes rejection (93.91% for Orange GII and over 99% for Methyl blue, Congo red and Alcian blue). The high separation performance, coupled with its facile fabrication and remarkable stability, may render imine-based COFs membrane promising for wastewater treatment.
Zhinan Fan,Xiao Chen,Ranran Kong,Yaoqi Lu,Rongliang Ma,Jia-Wei Wu,Li-Juan Fan
Taking the same developing strategy for different types of latent fingerprints is helpful in improving the efficiency of criminal investigation. Here we advanced a new strategy based on amino-functionalized poly( p -phenylenevinylene) nanoparticles (PPV-brPEI NPs) in aqueous colloidal solution as the developing reagent. The desirable amino functionality and strong emission of NPs were simultaneously realized by adding branched polyethyleneimine (brPEI) during the process of thermal elimination of the PPV polymer precursor. The NPs were demonstrated to have negligible effects on the extraction of biological information from DNA . Using the PPV-brPEI NPs-soaked cotton pad, both latent sebaceous fingerprints (LSFPs) and latent blood fingerprints (LBFPs) can be effectively developed on different nonporous substrates. This strategy was highly sensitive and effective for aged, contaminated and moldy fingerprints. Additionally, the developed fingerprints could tolerate humidity environment and the alcohol atmosphere. The mechanism investigation suggests that interaction between PPV-brPEI NPs and sebum ingredients contributes to the development of LSFPs and interaction between PPV-brPEI NPs and proteins in blood contributes to the development of LBFPs, but the former is not as stable as the latter. This work provides a simple, environment/operator-friendly strategy for efficient fingerprint development, which is very promising for practical criminal investigations.
危险品化学品经营许可证（带存储）