Substrate matters:The influences of substrate layers on the performances of thin-film composite reverse osmosis membranes

Thin-film composite(TFC) reverse osmosis(RO) membranes are playing the dominating role in desalination.Tremendous efforts have been put in the studies on the polyamide selective layers. However, the effect of the substrate layers is far less concerned. In this review, we summarize the works that consider the impacts of the substrates, including pore sizes, surface hydrophilicity, on the processes of interfacial polymerization and consequently on the morphologies of the active layers and on final RO performances of the composite membranes. All the works indicate that the pore sizes and surface hydrophilicity of the substrate evidently influence the RO performances of the composite membranes. Unfortunately, we find that the observations and understandings on the substrate effect are frequently varied from case to case because of the lack of substrates with uniform pores and surface chemistries. We suggest using track-etched membranes or anodized alumina membranes having relatively uniform pores and functionalizable pore walls as model substrates to elucidate the substrate effect.Moreover, we argue that homoporous membranes derived from block copolymers have the potential to be used as substrates for the large-scale production of high-performances TFC RO membranes.

MECHANICAL PROPERTIES AND INTERFACIAL STRUCTURES OF ALUMINIUM BORATE WHISKER REINFORCED ALUMINIUM COMPOSITES

Quality 9Al2O3-2B2O3 whisker reinforced 6061Al or Al composites have beenprepared by technique of squeeze casting.The mechanical properties of the9Al2O3·2B2O3（w）/6061Al composites could be hardly improved by T6 treatment,owingto cause the remarkable interracial reaction.An observation under high resolution trans-mission electron microscope on interfaces shows that the serious chemical reaction occursand the product is Al2MgO4.But no such reaction is found at the interfaces of 9Al2O3.2B2O3（w）/Al composite.EDS analysis on the interfaces shows that above mentionedinterracial reaction may be resulted from the interracial segregation of Mg atoms in6061Al matrix during sequeeze casting.

Interfacial and electrical properties of HfAIO/GaSb metal-oxide-semiconductor capacitors with sulfur passivation Interfacial and electrical properties of HfAIO/GaSb metal-oxide-semiconductor capacitors with sulfur passivation Interfacial and electrical properties of HfAIO/GaSb metal-oxide-semiconductor capacitors with sulfur passivationInterfacial and electrical properties of HfAIO/GaSb metal-oxide-semiconductor capacitors with sulfur passivation

Interfacial and electrical properties of HfA10/GaSb metal-oxide-semiconductor capacitors （MOSCAPs） with sulfur passivation were investigated and the chemical mechanisms of the sulfur passivation process were carefully studied. It was shown that the sulfur passivation treatment could reduce the interface trap density Dit of the HfAIO/GaSb interface by 35% and reduce the equivalent oxide thickness （EOT） from 8 nm to 4 nm. The improved properties are due to the removal of the native oxide layer, as was proven by x-ray photoelectron spectroscopy measurements and high-resolution cross-sectional transmission electron microscopy （HRXTEM） results. It was also found that GaSb-based MOSCAPs with HfA10 gate dielectrics have interfacial properties superior to those using HfO2 or A1203 dielectric layers.

Influence of Interfacial Bonding between Metal Droplets on Tensile Properties of 7075 Aluminum Billets by Additive Manufacturing Technique

7075 aluminum billets were fabricated by micro droplet deposition manufacturing technique,and the influence of interfacial bonding between metal droplets on the tensile properties was studied.Three sets of samples were manufactured under different temperature conditions,and their mechanical properties were compared.The results show that the temperature of the metal droplets and substrate signi?cantly affect the tensile strength of the sample.Moreover,with proper temperature setting,the 7075 aluminum billets manufactured by micro metal droplet deposition could achieve very good mechanical properties with a tensile strength of 373 MPa and an elongation of 9.95%,which are very similar to those of an extruded sample.Moreover,a metallurgical bonding diagram based on numerical calculations of interfacial temperature was established to predict the interfacial bonding state.In addition,the fracture morphologies of these specimens were observed.It is indicated that there was a signi?cant transformation of failure mechanism with the improvement of metallurgical bonding,which agreed well with the numerical results.

Modification of Oil Palm Empty Fruit Bunch and Sugarcane Bagasse Biomass as Potential Reinforcement for Composites Panel and Thermal Insulation Materials

This paper focuses on the study of the effect of modification of Oil Palm Empty Fruit Bunch(OPEFB)and sugarcane bagasse(SCB)biomass as potential reinforcement for composites panel and thermal insulation.Both fibres were treated with three types of chemicals:2%silane,4%H2O2 and 4%H2O2-2%silane for 3 h.The influence of modified fibres content in composites was examined by structural changes using image analyser,Fourier transform infrared(FTIR),Scanning Electron Microscopy(SEM),tensile,interracial shear strength(IFSS)and thermal characteristic.The diameter of both fibres was reduced after treatment and showed decreasing of lignin and hemi-cellulose in fibre.Tensile strength has been increased by 2%silane treatment for both fibres and 4%H2O2 treatment displays higher result for IFSS.Thermal properties of treated SCB fibre with silane display higher residual content and better thermal stability.SEM charac-terization showed that 2%silane treatment removed silica bodies of OPEFB fibre while 4%H2O2 treatment uniformly filled porosity of SCB fibre.Finally,results revealed that treated OPEFB fibre is enough to improve compatibility and mechanical properties,while treated SCB fibre was effective in thermal stability for fabrication of composite materials.

Preparation of 3D MnO2/Polyaniline/Graphene Hybrid Material viaInterfacial Polymerization as High-Performance Supercapacitor Electrode

MnO2/polyaniline/graphene composite as a supercapacitor electrode material was synthesized through an inter-facial polymerization approach in the interface of oil/water phase. The as-synthesized MPG is characterized by in-frared spectroscopy, XRD, XPS, SEM and TEM, and its electrochemical performance is measured by cyclic volt-ammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. The 3D nanostructure ofMPG and loose nanorod structure of polyaniline （PANI） coated with round MnO2 pellets could be clearly observed.The maximum energy density of MPG is 45.4 Wh/kg （at a power density of 67.8 kW/kg） and the highest powerdensity is 229.2 kW/kg （at an energy density of 25.7 Wh/kg）. The capacitance retentions after 500 cycles at the scanrate of 5 mV/s for MGP composite and PANI/graphene are 70.4% and 59.1%, respectively, and the capacitancevalues after 500 cycles are 158.4 F/g and 114.8 F/g, respectively. The improved performance of MPG is due to the3D nanostructure, loose nanorod structure of PANI and stable support of graphene, which prevent the mechanicaldeformation effectively during the fast charge/discharge process and facilitate the diffusion of the electrolyte ionsinto the inner region of active materials. The composite material is very promising for the next generation ofhigh-performance supercapacitors electrode.