Generation Of Porous Structure Research Articles

Chemical recycling of waste Poly Vinyl Chloride (PVC) by the liquid-phase treatment

Liquid-phase treatment of waste Poly Vinyl Chloride (PVC) was performed. Chlorine change rate was high when using alcohol, cresol and terpene compared with that observed in the treatment without solvent, so the importance of solvent for dechlorination from PVC was confirmed. By the treatment in alcohol, generation of porous structure was confirmed, which were not observed in the treatment of PVC alone. We were able to propose a method of utilizing carbon resources after chlorine is removed from a different perspective than previous reports. The number of pores and pore size were controlled by adding CO2 gas and basic compound, especially Na2CO3 in 1-Butanol. It indicated that these elements were effective for the production of porous structure based on the liquid-phase treatment. On the other hand, solubilization rate reached near 90% by using terpene at 300 °C in air atmosphere. The most effective solvent for solubilization was o-Cresol and solubilization rate reached to 99.8% at 250 °C in air atmosphere. This result indicates that PVC can be completely decomposed by these solvents in the presence of oxygen. From this research, it is possible to utilize and decompose solid residue by selecting the conditions.

Strategy to enhance the sugar production using recyclable inorganic salt for pre-treatment of oil palm empty fruit bunch (OPEFB)

Inorganic salts were used for the pretreatment of oil palm empty fruit bunches (OPEFB) to enhance the delignification and saccharification yield of OPEFB. The sequential pretreatment of OPEFB using sodium phosphate dodecahydrate (Na3PO4.12H2O) and zinc chloride (ZnCl2) proved to be an effective approach. OPEFB was delignified by 58.8%, producing a maximum total reducing sugar (TRS) yield of 0.97 g/g under optimum pretreatment conditions of 15% Na3PO4.12H2O, 60 min (30 min/stage) pretreatment time, 10% solid to liquid ratio, and pretreatment temperature of 121 °C. In addition, structural and morphological analysis of the pretreated OPEFB using field emission scanning electron microscope (FESEM), Fourier transform infrared (FTIR) spectroscopy, and X- ray diffraction (X-RD) revealed major structural changes, such as the generation of porous structure, which allows for better enzyme accessibility. Moreover, recycle experiments showed encouraging findings, as the spent pretreatment liquid with pH adjustment can be recycled efficiently for at least 5 times without a substantial decrease in its effectiveness.

Exact Stoichiometry of Ce xZr6- x Cornerstones in Mixed-Metal UiO-66 Metal-Organic Frameworks Revealed by Extended X-ray Absorption Fine Structure Spectroscopy.

Bimetallic Ce/Zr-UiO-66 metal-organic frameworks (MOFs) proved to be promising materials for various catalytic redox applications, representing, together with other bimetallic MOFs, a new generation of porous structures. However, no direct proof for the presence of both metals in a single cornerstone of UiO-type MOFs was reported so far. Employing element-selective X-ray absorption spectroscopy techniques herein, we demonstrate, for the first time, that our synthesis route allows obtaining Ce/Zr-UiO-66 MOFs with desired Ce content and bimetallic CeZr5 cornerstones. Performing multiple-edge extended X-ray absorption fine structure analysis, we determine the exact stoichiometry of the cornerstones, which explains the dependence of thermal and chemical stability of the materials on Ce content.

Silica-Resorcinol-Formaldehyde Aerogels Nanostructure Modelling

The work is devoted to the study and modelling of the internal nanostructure of silica-resorcinol-formaldehyde aerogels. These aerogels are highly porous (up to 98 %) functional materials with a high specific surface area, low thermal conductivity, and good sound insulation. This material is of interest for use in thermal insulation, gas sorption, and also as a soundproof material. In addition, silica-resorcinol-formaldehyde aerogels are a material for further pyrolysis to obtain silica-carbon aerogels. Several aerogel samples experimental data were analysed. The experimental data includes amount of solvent, silica to resorcinol-formaldehyde ratio, pore size distribution, density, and specific surface area. The size and volume of different pores and specific surface area vary depending on the gelation conditions of the samples. This fact indicates the gelation conditions have a significant effect on the final aerogel structure. However, the input parameters of the model are the pore size distribution and sample density. Analysis and comparison of two methods for the generation of porous structures of silica-resorcinol-formaldehyde aerogels including Diffusion-Limited Cluster Aggregation (DLCA) and Reaction-Limited Cluster Aggregation (RLCA) are carried out and the advantages of these two methods are shown in this paper.

Generation of Porous Structure from Basil Seed Mucilage via Supercritical Fluid Assisted Process for Biomedical Applications

Mucilage’s are plant derived natural polymer which are valuable due to their nontoxicity, low cost and nonirritating nature, with wide range of applications.