Papers by Keyword: Membrane Material

Abstract: Spent Bleaching Earth (SBE) is a solid waste produced from the palm cooking oil refining industry. The commercial ceramic membranes are quite pricey, therefore SBE solid waste is possible to be an alternative for reduction of membrane material cost due to high silica content. This work demonstrates the fabrication of ceramic tubular support membrane with varied SBE addition and investigates the functionalization group of its membranes. The ceramic support membrane was prepared from regeneration SBE with varied loading composition 15 and 35 wt%. The regeneration SBE using n-Hexane as solvent. Membranes were casted into tubular configuration using centrifugal casting technique at 3000 rpm. The tubular ceramic SBE membranes were dried and followed by calcined at 900°C with heating rate 2°C/min using programable furnace for 2 h. Both of raw SBE material and membranes were analyzed using Fourier transform infrared (FTIR). The SBE material after regenerated exhibits has high Si-OH and Si-O-Si peaks over raw material. Interestingly, the fabrication ceramic support membrane with tubular configuration is successfully preparation by centrifugal casting. Ceramic SBE membrane exhibits functionalization and deconvolution the present of siloxane, Al-OH-Al, Ti-O-Ti, and Al-O bands for both of 15 and 35wt% SBE loading. It concluded this tubular ceramic support membrane from SBE has appropriated chemical functionalize properties to applicates as membrane separation.

Abstract: Membrane materials became the focus of the exhibition design sector in the 1970s and have developed rapidly since then. As a fabric material of excellent performance, the membrane material has been widely and innovatively used in recent years for their features of facilitating construction and transportation, energy efficiency and environmental friendliness, as well as easy combination with other materials and units. Those innovative applications not only render new functions to membrane materials, but also provide new ideas and open a new horizon to the design of the exhibition pavilions. The use of member materials will also become the mainstream of the exhibition design sector in the near future.

Abstract: Membrane distillation (MD) integrates membrane technology with evaporation process to produce fresh water from seawater or contaminated water. In this study, we investigated the effect of membrane materials on the efficiency of membrane distillation process. Flat sheet hydrophobic membranes (PVDF, PTFE) with different characterizes were chosen as well as hollow fiber membranes (PE). Laboratory-scale systems were developed for initial screening of various membranes. The performance of the membrane was analyzed in terms of water permeability and salt rejection. Synthetic seawater (TDS = 35,000 mg/L) was used for the lab-scale tests. A simple model to analyze the transport of water through MD membranes was developed to interpret experimental results. In addition, long-term performances of the membranes were compared to examine the stability of membrane materials and fouling tendency using real seawater. Based on the lab-scale experiments, techniques to improve the performance of the membranes were examined by applying physical and chemical modification.

Abstract: Pd-based composite membranes are the attractive membrane materials for hydrogen separation due to their high hydrogen permeability and infinite permselectivity. Thin pure Ni and Pd-Ni alloy membranes with high hydrogen permeation were prepared by the electroless plating method. It is difficult to prepare the dense pure Ni membranes with 1-2 μm thickness for hydrogen separation. However, Pd-Ni alloy membranes with several micrometers thickness showed good permeation performance. Hydrogen permeance of the Pd95Ni5 alloy membrane with fcc phase up to 3.1×10-6 mol/m2 s Pa and the ideal permselectivity over 600 were obtained at 773 K.

Abstract: The tensile performance of the woven membrane materials shows three characters: nonlinear, anisotropic and non-elastic. Besides, when suffering from the bi-axial loads, the tensile property of the woven membrane material is more complicated. These features make the analysis of the tensile performance of woven membrane materials more difficult. The analysis methods including the elastic matrix method, the mathematical function method, and the mechanical model method have been discussed in details.

Abstract: As a kind of flexible fabric reinforced composites, the woven membrane materials suffer from the bi-axial tensile loads in the application of the lightweight structures. Therefore, the experiments under bi-axial tensile loads are essential for the acquaintance of the mechanical characters of the membrane materials. This paper has summarized thoroughly the details of the bi-axial tensile tests, especially the in-plane cruciform tests. The aspects include the shape and configuration of the cruciform sample, the practice of the applied stresses and the testing of the strains in the two axial directions. It could be expected to be the reference for the establishment of the testing standard of the bi-axial tensile experiment for the membrane materials.

Abstract: This paper focused on the tensile performance of PVC-coated membrane materials under multi-axial loads. Several groups of experiments were carried out to investigate the effect of the specimen configuration and the loading speed on the tensile properties. It could be concluded that the configuration of the specimen plays an important role on the tensile performance of the materials. The suitable configuration for multi-axial loading tests had been identified. It was also found out that the loading speed had certain effect on the tensile failure performance and the tensile response. A loading speed of lower than 20mm/min was suggested to achieve a reasonable result of the multi-axial tensile performance of PVC-coated membrane materials. Another group of tensile experiments with a crack in the center of the specimens under multi-axial loads were performed. It was noticed that the tensile properties in warp direction of the coated membrane materials play an important role in the tensile failure under multi-axial loads, no matter the initial crack length and the crack orientation are.

Abstract: The method of wettability of solid-liquid interface is used to examine the differences of the liquid membranes formed by hydrophilic or hydrophobic membranes with different size and different materials, the influence of the characteristics of membrane modules in the process of desulfurization is studied. The method of accelerating the renewing rate of liquid membrane is proposed. The results show that the hydrophobic liquid membrane leads to higher renewing rate and absorption efficiency of sulfur dioxide and the hollow fiber membrane of polypropylene has higher adsorption efficiency. The dynamic contact angle of the same hollow fiber membrane is increasing with the number of the fibers leading to the increase of the diffusing resistance of liquid between the fibers. In order to accelerate the renewing rate of the liquid membrane, the concentration of the medium should be decreased under the condition of high absorption capacity.

Abstract: The aim of this research is to find a feasible method for the estimation of the tensile behaviour of woven membrane construction materials under bi-axial loading. During the model development, the woven membrane materials are treated as orthotropic, elastic and linear. Based on the constitutive relationships for orthotropic and elastic materials, two equations sets are deduced for the estimation of modulus in the warp and the fill direction respectively when suffering from the bi-axial loading. To checkout the validity of the estimation, seven groups of biaxial tensile tests with stress ratios of 1:0, 1:1, 2:1, 5:1, 1:2, 1:5 and 0:1 have been carried out on two kinds of PVCcoated woven membrane materials. From the comparison of the experiments and the prediction, it can be noticed that the model can achieve ideal results when it comes to the estimation of modulus in the leading direction, which is the direction with a higher stress than the other one. Therefore, based on the hypothesis of orthotropic, elastic and linear materials, there is an easy way to estimate the bi-axial tensile properties of woven membrane materials in the leading direction only through the uni-axial tensile tests.