Improved blending strategy for membrane modification virtue of surface segregation using surface-tailored amphiphilic nanoparticles

Membrane modification is one of the most feasible and effective solutions to membrane fouling proble.m which tenaciousl.y hampers .the furher au .gmentation of me .rnbrane sep.aration technology.Blending modification with nanoparticles （NPs）, owing to the convenience of being incorporated in established membrane.p.rodu. ction lines, possesses an advantag, eous viability in practical applications.However, the existing blending strategy suffers from a low utilization efficiency due to NP encasement by membrane matrix. The current study proposed an improved blending modification approach with amphiphilic NPs （aNPs）, which were prepared through silanization using 3-（Trimethoxysilyl）propyl methacrylate （TMSPMA） as coupling agents and ZnO or SiO2 as pristine NPs （pNPs）, respectively.The Fourier transform infrared and X-ray photoelectron spectroscopy analyses revealed thepresence of appropriate organic components in both the ZnO and SiO2 aNPs, which verified the success of the silanization process. As compared with the pristine and conventional pNP-blended membranes, both the ZnO aNP-blended and SiO2 aNP-blended membranes with proper silanization （100% and 200% w/w） achieved a significantly increased blending efficiency with more NPs scattenng on the internal and external membrane surfaces under scanning electron microscope observation. This improvement contributed to the increase of membrane hydrophilicity. Nevertheless, an extra dosage of the TMSPMA led to an encasement of NPs, thereby adversely affecting the properties of the resultant membranes. On the basis of all the tests, 100% （w/w） was selected as the optimum TMSPMA dosage for blending modification for both the ZnO and SiO2 types.

Superhydrophobic modification of ceramic membranes for vacuum membrane distillation

The hydrophobically modi fied ceramic membranes have great potential for energy-ef ficient membrane distillation.In this work,flat-sheet ceramic membranes with a superhydrophobic surface were fabricated by grafting 1H,1H,2H,2H-per fluorooctyltrichlorosilane or 1H,1H,2H,2H-per fluorodecyltriethoxysilane and followed by ultraviolet irradiation.The surface water contact angle was improved from 46° of original ceramic membrane to 159°,which exhibited a stable and excellent superhydrophobic effect.The modi fied membranes showed a high flux of 27.28 kg·m^(-2)·h^(-1) and simultaneously maintained an excellent retention rate of 99.99%,when used in vacuum membrane distillation process for treatment of a 1 wt% NaCl(75 °C) aqueous solution.These results suggested that superhydrophobic modi fication of ceramic surface is a facile and cost-effective way to achieve higher membrane distillation performance.The superhydrophobically-modi fied ceramic membrane with an excellent desalination capacity would show considerable potential in practical membrane distillation utilizations.

Atomic layer deposition of Al_2O_3 on porous polypropylene hollow fibers for enhanced membrane performances

Porous polypropylene hollow fiber(PPHF) membranes are widely used in liquid purification. However, the hydrophobicity of polypropylene(PP) has limited its applications in water treatment. Herein, we demonstrate that, for the first time, atomic layer deposition(ALD) is an effective strategy to conveniently upgrade the filtration performances of PPHF membranes. The chemical and morphological changes of the deposited PPHF membranes are characterized by spectral, compositional, microscopic characterizations and protein adsorption measurements. Al_2O_3 is distributed along the cross section of the PP hollow fibers, with decreasing concentration from the outer surface to the inner surface. The pore size of the outer surface can be easily turned by altering the ALD cycles. Interestingly, the hollow fibers become much more ductile after deposition as their elongation at break is increased more than six times after deposition with 100 cycles. The deposited membranes show simultaneously enhanced water permeance and retention after deposition with moderate ALD cycle numbers.For instance, after 50 ALD cycles a 17% increase in water permeance and one-fold increase in BSA rejection are observed. Moreover, the PP membranes exhibit improved fouling-resistance after ALD deposition.

Effects of Nano-patterning Modification on the Cell Proliferation and Adhesion in Burn Wound Healing of Regenerated Silk Fibroin Membrane

Objective:To investigate the effect of nano-patterning modification on the cell proliferation and adhesion in burn wound healing of regenerated silk fibroin membrane.Methods:A total of 60 healthy SD mice were randomly divided into three groups:group A received treatment involving nano-patterning on the surface of regenerated silk fibroin membrane,group B received treatment with recombinant human epidermal growth factor gel,and group C received the same treatment with recombinant human epidermal growth factor gel,with 20 cases in each group.Wound healing,surface structure,protein adsorption,cell proliferation and adhesion were assessed at intervals of 5th,15th and 25th d after treatment.Results:The findings indicated that:(1)The duration and pace of wound healing in groups A and B surpassed those of group C,with group A exhibiting superior results compared to group B(P<0.05);(2)Histopathological analysis revealed a progressive increase in neovascularization and fibroblast count in wound tissue across the 5th,15th,and 25th days for all three groups,with group C exhibiting a higher count of neovascularization and fibroblasts in unhealed tissue compared to groups A and B.(3)The levels of basic calponin expression in group A and group B showed an increase on the 5th and 15th day,followed by stabilization on the 25th day.In group C,the expression of basic calponin was initially high on the 5th day,and then stabilized on the 15th and 25th day(P<0.05);(4)The expression of fibroblast proliferating cell nuclear antigen in the wound tissue of mice in all three groups peaked on the 15th day and subsequently declined.The expression of PCNA in group A and group B was higher than that in group C at each time point,with group A exhibiting higher levels than group B(P<0.05);(5)As wounds healed,there was a reduction in apoptotic cells within the wound tissues of mice across three groups,with group a exhibiting a lower count compared to groups B and C(P<0.05).Conclusion:Nanopatterning on the surface of regenerated silk fibroin membrane can enhance the biocompatibility of burn wound treatment and promote the proliferation and adhesion of reparative cells.

Cable-like Au@SiO2 Janus composite nanorods

Cable-like Au@SiO2 Janus composite nanorods with PS and PEG grafting on both ends respectively are fabricated by skiving in combination of a post favorable modification. The cable-like Au@SiO2 composite nanofibers are synthesized in the channel of porous anodic aluminium oxide （AAO） membrane. After skiving, the corresponding composite nanorods are obtained. Following, PEG-SH and PS-SH are conjugated onto the two ends of the nanorods by a selective partial modification, respectively. Length and diameter of the Au@SiO2 Janus composite nanorods can be tuned controllably. It can be extended to fabricate a variety of different Janus nanorods with different compositions and microstructures.