SYNTHESIS AND CHARACTERIZATION OF HYBRID MEMBRANE POLYVINILIDEN FLUORIDE MODIFIED BENTONITE ORGANO MERCAPTO SILANE (PVDF- BNT/MPTMS) FOR MICROFILTRATION OF TEXTILE DYE

• Main Author: Ruqayyah
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/55111
• Institution: Institut Teknologi Bandung

The problem of textile industrial waste treatment can be solved using membrane technology. Polyvinylide fluoride (PVDF) is widely used for membranes because of several advantages, namely mechanical properties, thermal properties and chemical resistance, but because of its hydrophobic nature, fouling on the membrane surface is the main problem of PVDF membranes. The hydrophobic nature of PVDF can be overcome in several ways, one of which is by modifying it. Membrane modifications with the addition of hydrophilic inorganic materials as membrane fillers are widely used because they are easy to manufacture and proven to improve the thermal, mechanical and performance properties of membranes. Bentonite (BNT) is a clay compound based on aluminum silica which is hydrophilic, abundant and inexpensive so that it has the potential to be a filler for PVDF membranes for dye filtration applications. The addition of BNT to hydrophobic polymers often results in agglomeration processes caused by differences in surface tension of each component. Therefore, BNT is modified by adding a silane compound, namely 3-mercaptopropyl trimethoxy silane (MPTMS). In the research on synthesis and characterization of PVDF-BNT/MPTMS hybrid membranes for textile dye microfiltration, BNT modification with MPTMS, synthesis of PVDF-BNT/MPTMS hybrid membranes and characterization of synthesized hybrid membranes was carried out. First, bentonite is modified with MPTMS. The modification results were characterized by FTIR and XRD. From the FTIR results, it can be concluded that BNT was successfully modified with MPTMS which was marked by the appearance of new peaks at wave numbers 2930, 2562 and 1451 cm-1 which were the streching vibrations of C-H, S-H and the scissoring band from C-H. From the results of XRD characterization, it is known that MPTMS binds to the surface of the BNT aluminosilicate. Furthermore, BNT which has been modified with MPTMS is used in the synthesis of PVDF-BNT/MPTMS hybrid membranes. In the PVDF-BNT/MPTMS hybrid membrane synthesis, the composition of the BNT/MPTMS used was varied. The variation in the composition of the BNT/MPTMS used is 0.25; 0.5; 0.75 and 1% w/w. Meanwhile, the PVDF and porogen compositions used were fixed at 18 and 4% w/w, respectively. The solvent composition is adjusted according to the added BNT/MPTMS composition. The porogens and solvents used were polyethylene glycol (PEG) and N, N-dimethyl acetamide (DMAc). PVDF-BNT/MPTMS hybrid membranes were synthesized by phase inversion method. The synthesized hybrid membrane was then characterized, including characterization of membrane surface hydrophilicity, porosity, pore size, membrane mechanical properties, membrane performance against methylene blue (MB) dye with concentrations of 50 and 1000 ppm and its antifouling properties. From the results of the study, the presence of BNT/MPTMS in the membrane can increase membrane hidrophilicity which is indicated by decreasing the contact angle of water on the membrane surface. The porosity and pore size of the membranes were characterized by gravimetric and buble point testing methods, respectively. The porosity of the hybrid membrane tends to decrease, while the pore size increases. Mechanical properties of hybrid membranes characterized are elongation and tensile strength at break. From the results of the study, the presence of BNT/MPTMS decreased the elongation and tensile strength at break of the membrane or it could be said that the hybrid membrane became more brittle compared to pure PVDF membranes. From the results of the study, the presence of BNT/MPTMS tended to increase the selectivity and permeability of the membrane against the MB 50 and 1000 ppm dye. The antifouling ability of the membrane was measured by the value of the Flux Recovery Ratio (FRR). FRR is calculated by comparing the water flux in the membrane before use for dye filtration with the water flux in the membrane after being used for dye filtration. PVDF-BNT/MPTMS0.5% membrane showed the best performance against MB dye. The selectivity of the PVDF-BNT/MPTMS0,5% membrane was against MB 50 and 1000 ppm dye 99.33 and 84.62%, respectively. The antifouling ability measured from the value of Flux Recovery ratio (FRR) of the PVDF-BNT/MPTMS 0.5% membrane against MB 50 and 1000 ppm dye were 56 and 92%, respectively.