Rosiah Rohani

Membran Penurasan-Nano Campuran Polietersulfon/Pluronik F127 untuk Penulinan Xilitol

Obtaining high purity of xylitol is a stone corner in medicine industries. Many conventional techniques (crystallization and adsorption) were used for xylitol purification from fermentation media. Recently, membrane technology received a great attention due to its high performance in xylitol purification. Among renowned copolymers used for polymer blending to produce membranes, pluronic is receiving much attention due to its strong hydrophilic characteristic and could work as pore former and surface modifier. Polyethersulfone (PES) polymer has been reportedly used for polymer blending as it possesses mechanical and chemical stabilities. Therefore, this work demonstrates the preparation of nanofiltration (NF) membrane using: (1) PES and (2) PES blended with 1.71% and 5% of Pluronic (F127), via phase inversion method. All fabricated membranes were subjected to investigations such as contact angle for hydrophilicity and water and solution flux for membrane performance. The findings showed increasing in water flux from 24.6 L/m.h to 70.2 L/m.h as 5% of Pluronic added. Further, the hydrophilicity improved from 80.1 ± 1.93 to 72 ±0.3 and 67.6 ± 0.72 when 1.71 and 5% of Pluronic F127 added respectively. Therefore, the addition of Pluronic f127 has a great impact on PES membrane for xylitol permeation.

Penentuan berat sekatan molekul bagi membran penurasan tekananmelalui kaedah pengesanan kolorimetri

Molecular weight cut-off (MWCO) of commercial and in-house fabricated membranes is obtained at 90% rejection of various types of solutes with different molecular weights (MWs). PEG quantification methods have been favorably employed to determine membranes’ MWCO. Most of the quantification methods utilizing high-end equipment using high performance liquid chromatography (HPLC) and low-end colorimetric method. HPLC method requires an established chromatographic technique using specific diluents, columns and detectors while the most referred colorimetric method requires a few processing steps with concentration up to 7.5 ppm by using UV spectrophotometer. In this work, a newly modified colorimetric method was established to conduct a simple measurement for a membrane’s MWCO. The newly modified method has an excellent linearity for the calibration curves which R values are closed to 1 with concentration of up to 150 ppm. A MWCO determination test conducted using different commercial membranes for confirming this newly modified method found that similar MWCO values were obtained as given by the membrane’ manufacturers. In conclusion, this newly modified method is simpler than the formerly used colorimetric method, reliable and applicable for determining the MWCO of membranes ranging from UF to NF at a higher range of PEG concentrations (>150 ppm).

Evaluation of the operating parameters for the separation of xylitol from a mixed sugar solution by using a polyethersulfone nanofiltration membrane

Nanofiltration (NF) membranes may offer a good route for the recovery of xylitol due to the difference in the size of its particles compared to the other sugars. We evaluated the ability of an in-house polyethersulfone (PES) NF membrane to separate xylitol from a simulated broth solution containing xylose and arabinose. Initially, a Box-Behnken design was utilized to optimize the factors that were significantly involved in the recovery of xylitol, such as the concentration of the components, the composition of the solution, and the pressure. The results obtained from the analysis of the experimental response revealed that the fabricated PES membrane was able to retain 92% of the xylitol and remove 50% of the arabinose, with the purity of the xylitol being enhanced accordingly. The results of fouling showed a good membrane performance for long-term filtration. The concentration polarization was dominated by the membrane pores and the charge. It could be concluded that nanofiltration has a high potential to recover xylitol from its corresponding sugars.

Synthesis of Iron Oxide Nanoparticles to Enhance Polysulfone Ultrafiltration Membrane Performance for Salt Rejection

Synthesis of Iron Oxide Nanoparticles to Enhance Polysulfone Ultrafiltration Membrane performance for Salt Rejection Muneer M. Ba-Abbad*, Abdul Wahab Mohammad, Mohd S. Takriff, Rosiah Rohani, Ebrahim Mahmoudi, Khalefa A. Faneer, Abdelbaki Benamo Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia. Research Centre for Sustainable Process Technology (CESPRO), Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor, Malaysia. Gas Processing Centre, Qatar University, P. O. Box 2713 Doha, Qatar. Department of Chemical Engineering, Faculty of Engineering and Petroleum, Hadhramout University of Science &Technology, Mukalla, Hadhramout, Yemen. muneer711@gmail.com

Polyethersulfone nanofiltration membrane incorporated with silicon dioxide prepared by phase inversion method for xylitol purification

Xylitol purity is essential for a high value product obtained from biomass fermentation. Common biomass fermentation from sugar cane bagasse, corncobs or rice husk source in the presence of yeast produces xylitol mixture (containing xylose, arabinose), thus, various methods have been used for the purification such as crystallization and adsorption. However, membrane technique is of interest due to the operational simplicity and flexibility, relatively high selectivity and permeability for the transport of specific components. Nanofiltration (NF) membrane is targeted for the membrane application based on the ranges of molecular weight of the mixture components that fall in NF (between 200 to 2000 g/mol). In this paper, a new and efficient NF membrane used for purifying xylitol was synthesized from polyethersulfone (PES) and PES incorporated with silicon dioxide (SiO2) nanoparticles (NP) of 5 wt.% via phase inversion technique. These membranes have been characterized for their chemical, physical and morphological properties and their performances have been evaluated in the dead end filtration to obtain the pure water flux and filtration performance using xylitol mixture. EDX showed the presence of SiO2 NP on the membrane for PES/SiO2 membrane but none in PES membrane. The membrane permeation properties improved also when SiO2 has been incorporated to the PES membrane. The hydrophilicity of the PES/SiO2 membrane measured by contact angle improved from 79.7±0.65° to 59.1±0.15° for PES/SiO2 and PES membranes, respectively. The water flux has enhanced for PES/SiO2 membrane from 24.56 to 59.14 L/m2·h measured at 4 bar. Therefore, in terms of flux and contact angle, the synthesized membrane of PES/SiO2 was found to be more effective compared to pure PES membrane.

Influence of pluronic addition on polyethersulfone membrane for xylitol purification

Xylitol is an important raw material in cosmetic, pharmaceutical and food industries due to its non-cariogenic sweetener properties. Xylitol in mixed sugars which obtained from fermentation media could be purified through adsorption or crystallisation. Xylitol may leach out during adsorption while the complexity of the fermentation broth in crystallisation has limits the utilisation of these techniques. The use of membrane filtration technique is foreseen could avoid these limitations as its separation is based on the solutes size, shape and/or molecular weight ranges. In this work, special blend polymer membranes were synthesised, characterised and tested in the xylitol recovery from synthetic solution. Pluronic F127 at 1 %, 3 %, and 5 % was blended with polyethersulfone (PES) to modify membranes. The effect of Pluronic ratio on the membrane selectivity for xylitol separation from sugars and also the fouling mitigation effect under Pluronic presence in the membranes were investigated. The results showed an improvement in the membrane hydrophilicity, where the contact angle of pure PES membrane has dropped from 80° to 65° in addition of Pluronic at different ratios. The water flux has also increased as the Pluronic ratio increased. The rejection of xylitol has found to decrease in Pluronic presence. Surprisingly, the membrane selectivity has enhanced greatly as desired. The PES blend Pluronic membranes have shown promising future in xylitol separation from sugars.

Polianilin multi-lapis bersalut pada polivinilidin fluorida dan elastomer silikon untuk membran penurasan bertekanan

In this study, silicone rubbers were used to achieve the desire absorbing properties of PANI onto polyvinylidene fluoride (PVDF) microporous support. Poly (methyl-vinyl ether-alt-maleic acid) (PMVEA) polymeric acid was used as acid dopant to enhance the membrane filtration performance. Initially PVDF micro-porous support was dip-coated with silicone rubber elastomer solution followed by deposition with PANI by in-situ chemical oxidative polymerisation techniques using two-compartment cell in presence of PMVEA and ammonium persulfate as the oxidizing agent. The PANI multilayer composite membranes were characterized by gravimetric for PANI content measurement namely Scanning Electron Microscope (SEM), Fourier-Transform Infrared (FTIR), Differential Scanning Calorimetry (DSC) and contact angle. The PANI content was found to be more than 30 %. SEM, FTIR and DSC analysis have confirmed the presence of PANI onto the multilayers membrane while the contact angle of the membrane in presence of high loading PANI was 0 o indicating the super hydrophilicity than without the PANI presence of 78.8 . The pressure filtration of PANI multilayer composite filtration membrane with a range of polyethylene glycols at different molecular weights was obtained based on the high flux up to 904.11 L/m.h and reasonable molecular weight cut off of below 20,000 g/mol were obtained for the synthesized membrane.