Synthesis and characterisation of MOF/ionic liquid/chitosan mixed matrix membranes for CO2/N2 separation

Mixed matrix membranes (MMMs) have been prepared by combining a small amount of highly absorbing non-toxic ionic liquid, [emim][Ac] (IL) (5 wt%), a biopolymer from renewable abundant natural resources, chitosan (CS), and nanometre-sized metal-organic framework (MOF) ZIF-8 or HKUST-1 particles to improve the selectivity of the IL-CS hybrid continuous polymer matrix. The TGA revealed that the thermal stability has been enhanced by the influence of both IL and ZIF-8 or HKUST-1 fillers, while keeping a water content of around 20 wt%, which suggests the potential of such materials for developing high temperature water resistant membranes for CO2 separation. The CO2 and N2 single gas permeation performance was tested at temperatures in the range of 25-50 C, to compare with the previously reported IL-CS hybrid membranes. The best CO2 permeability and CO2/N2 selectivity performance is obtained for 10 wt% ZIF-8 and 5 wt% HKUST-1/IL-CS membranes, as high as 5413 191 Barrer and 11.5, and 4754 1388 Barrer and 19.3, respectively. This is attributed to a better adhesion and smaller particle size of ZIF-8 than HKUST-1 nanoparticles with respect to the IL-CS continuous matrix, as interpreted by Hansen solubility parameters and Maxwell-based models, modified to account for rigidification, pore blockage and crystallinity of the CS matrix, with very accurate predictions.Financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) for the project CTQ2012-31229 at the University of Cantabria, and MAT2013-40556-R, at the University of Zaragoza, is gratefully acknowledged. C.C.C. and A.F.B. also thank the MINECO for the Ramon y Cajal contract (RYC-2011-08550) and the post-graduate research grant (BES2013-064266), respectively, at the Universidad de Cantabria. Dr. Sara Sorribas is gratefully thanked for her technical assistance on the XRD, SEM and TEM analyses. The microscopy work was done at the Laboratorio de Microscopias Avanzadas of the Instituto de Nanociencia de Aragon (LMA-INA), and the XRD measurements were carried out at the Servicio General de Apoyo a la Investigacion (SAI) of the Universidad de Zaragoza

Preparation of polyaniline asymmetric hollow fiber membranes and investigation towards gas separation performance

In this study, integrally skinned asymmetric hollow fiber membranes have been developed from emeraldine base form of polyaniline (PAni) for gas separation. High molecular weight PAni was synthesized in-house to provide the fresh supply of the polymer. The hollow fiber membranes were prepared using dry-jet wet spinning and the effects of air-gap distance on nascent fiber morphology, their gas permeation and mechanical properties were investigated. The spin-line stresses resulted in the molecular orientation of the polymer which had synergistic effect towards improving the gas performance of the PAni hollow fiber membranes. The induced molecular orientation also resulted in improvement in mechanical properties of the hollow fiber membrane. The use of volatile co-solvent, tetrahydrofuran (THF) assisted in the skin layer formation which showed a substantial improvement in the gas permeation performance of the hollow fiber as the time of evaporation was varied. Present PAni based hollow fibers showed a selectivity of 10.2 for O2/N2, 105.6 for H2/N2 and 7.9 for H2/CO2 with the H2 and O2 permeance of about 5.0 and 0.49×10-6cm3 (STP)/cm2scmHg, respectively

©IJAET ISSN: 22311963 DATA DERIVATION INVESTIGATION

Malicious software is a major issue in today’s computer world. Such software can silently reside in user’s computer and can easily interact with computing resources. It is necessary to improve the honesty of host and its system data. For improvement in security and honesty of host, this work is introduced. This mechanism ensures the correct origin or provenance of critical system information and prevents utilization of host resources by malware. Using this mechanism the source where a piece of data is generated can be identified. A cryptographic origin approach ensures system properties and system- data integrity at kernel level. A frame work is used for restricting outbound malware traffic. This frame work identifies network activities of malware. This frame work can be used as powerful personal firewall for investigating outgoing traffic of a host. Specifically, our derivation verification scheme requires outgoing network packets to flow through a checkpoint on a host, to obtain proper origin proofs for later verification INDEX TERMS — Authentication, malware, cryptography, derivation, networking. I