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Sonochemistry is the implementation of ultrasound wave to chemical reactions and processes. Remarkable progress has been achieved over the years on ultrasonic-assisted hydrothermal synthesis in zeolites. Ultrasonic irradiation is gaining popularity among researchers due to its ability in enhancing the zeolite crystallization and shortening significantly zeolite synthesis duration. In this project, zeolite RHO were synthesized via ultrasonic irradiation and followed by hydrothermal synthesis. The effect of ultrasonic irradiation on the synthesis of zeolite RHO was investigated. The zeolite RHO samples were characterized with X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy Dispersive X-ray (EDX). The application of ultrasonic irradiation treatment in current study has significantly shortened the synthesis duration of zeolite RHO from 7 days to 2 days compared to the conventional hydrothermal synthesis without ultrasonic irradiation treatment.

In recent years, mixed matrix membranes (MMMs) have received worldwide attention for their potential to offer superior gas permeation and separation performance involving CO2 and CH4. However, fabricating defect-free MMMs still remains as a challenge where the incorporation of fillers into MMMs has usually led to some issues including formation of undesirable interfacial voids, which may jeopardize the gas separation performance of the MMMs. This current work investigated the incorporation of zeolite RHO and silane-modified zeolite RHO (NH2–RHO) into polysulfone (PSf) based MMMs with the primary aim of enhancing the membrane’s gas permeation and separation performance. The synthesized zeolite RHO, NH2–RHO, and fabricated membranes were characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared-attenuated total reflection (FTIR-ATR), thermogravimetric analysis (TGA) and field emission scanning election microscopy (FESEM). The effects of zeolite loading in the MMMs on the CO2/CH4 separation performance were investigated. By incorporating 1 wt% of zeolite RHO into the MMMs, the CO2 permeability and ideal CO2/CH4 selectivity slightly increased by 4.2% and 2.7%, respectively, compared to that of a pristine PSf membrane. On the other hand, a significant enhancement of 45% in ideal CO2/CH4 selectivity was attained by MMMs incorporated with 2 wt% of zeolite NH2-RHO compared to a pristine PSf membrane. Besides, all MMMs incorporated with zeolite NH2-RHO displayed higher ideal CO2/CH4 selectivity than that of the MMMs incorporated with zeolite RHO. By incorporating 1–3 wt% zeolite NH2-RHO into PSf matrix, MMMs without interfacial voids were successfully fabricated. Consequently, significant enhancement in ideal CO2/CH4 selectivity was enabled by the incorporation of zeolite NH2–RHO into MMMs.

In recent years, there are increasing interest on applying ultrasonic irradiation for the synthesis of zeolite due to its advantages including remarkable shortened synthesis duration. In this project, the potential of ultrasonic irradiation treatment on the synthesis of zeolite RHO was investigated. Ultrasonic irradiation treatment time was varied from 30 to 120 minutes for the synthesis of zeolite RHO. The zeolite RHO solid samples were characterized with X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and nitrogen adsorption-desorption analysis. The application of ultrasonic irradiation treatment in this study has accelerated the synthesis of zeolite RHO where the synthesis duration has been significantly shortened to 2 days compared to 8 days required by conventional hydrothermal heating without ultrasonic irradiation treatment. Highly crystalline zeolite RHO crystals in truncated octahedron morphology were successfully formed.

Mixed matrix membranes (MMMs) separation is a promising technology for gas permeation and separation involving carbon dioxide (CO2). However, finding a suitable type of filler for the formation of defect-free MMMs with enhancement in gas permeability remains a challenge. Current study focuses on synthesis of KIT-6 silica and followed by the incorporation of KIT-6 silica as filler into polysulfone (PSF) polymer matrix to fabricate MMMs, with filler loadings of 0&ndash, 8 wt %. The effect of KIT-6 incorporation on the properties of the fabricated MMMs was evaluated via different characterization techniques. The MMMs were investigated for gas permeability and selectivity with pressure difference of 5 bar at 25 &deg, C. KIT-6 with typical rock-like morphology was synthesized. Incorporation of 2 wt % of KIT-6 into PSF matrix produced MMMs with no void. When KIT-6 loadings in the MMMs were increased from 0 to 2 wt %, the CO2 permeability increased by ~48%, whereas the ideal CO2/CH4 selectivity remained almost constant. However, when the KIT-6 loading in PSF polymer matrix was more than 2 wt %, the formation of voids in the MMMs increased the CO2 permeability but sacrificed the ideal CO2/CH4 selectivity. In current study, KIT-6 was found to be potential filler for PSF matrix under controlled KIT-6 loading for gas permeation.

Mimusops elengi seed shell powder (MESSP) was introduced as a new bio-filler in polypropylene (PP). The MESSP was characterized using a particle size analyzer, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and a thermogravimetric analyzer. MESSP was successfully melt mixed with polypropylene to produce bio-composite at various MESSP loading. The processability and properties of the bio-composites were characterized by using processing torques, differential scanning calorimetry, tensile test, water absorption, and SEM. The processability of PP was not affected by the addition of MESSP, which was revealed from the minimum changes in the processing torques, melting temperature, crystallization temperature, and degree of crystallinity. The tensile strength and elastic modulus of the bio-composites were improved with an addition of MESSP of up to 10 wt.%. However, the elongation at break and resistance to water absorption decreased slightly with increased MESSP loading. Morphological observations revealed that the MESSP showed good dispersion and adhesion in the PP matrix of up to 5 wt.% MESSP. Above 5 wt.% MESSP, agglomerates formed, which influenced the physical-mechanical properties of the PP and MESSP bio-composites. Results indicated that PP/MESSP composites can be used to replace PP in applications such as car dashboards and door panel, furniture, and rigid packaging.