Computational design and synthesis of molecular imprinted membranes for selective extraction of Quercetin

This thesis presents the fabrication of quercetin imprinted membranes (QIM) for selective extraction of quercetin through surface polymerization method. In the development of QIM, selection of functional monomer and the optimum molar ratio of template-monomer were facilitated by the application of m...

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محفوظ في:
التفاصيل البيبلوغرافية
التنسيق: أطروحة
اللغة:English
الموضوعات:
الوصول للمادة أونلاين:http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77973/1/Page%201-24.pdf
http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77973/2/Full%20text.pdf
http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/77973/4/Siti%20Fatimah.pdf
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الملخص:This thesis presents the fabrication of quercetin imprinted membranes (QIM) for selective extraction of quercetin through surface polymerization method. In the development of QIM, selection of functional monomer and the optimum molar ratio of template-monomer were facilitated by the application of molecular modelling through the use of HyperChem software. Three functional monomers were investigated including acrylamide, methacrylic acid and 4-vinylpyridine and the optimization of pre-polymerization complex was conducted at molar ratio of 1:1 to 1:5 for each of the monomers. The results indicated that molar ratio of 1:4, which involving the interaction between quercetin and acylamide could provide potentially favourable pre-polymerization complex prior to the synthesis of QIM. After this step had been established, QIM were developed based on the computational results. In order to deposit the imprinted layer on the surface of membrane, polyvinylidene fluoride (PVDF) membrane was used as the polymer support and then, they were subjected to thermal polymerization process and subsequent removal of template from the polymer matrix. QIM and non-imprinted membranes (NIM) were synthesized to evaluate and characterize the differences with respect to their morphology, chemical functionality as well as their binding behaviour towards quercetin and other components. The confirmation on the presence of imprinted layer on PVDF membrane was done through FTIR, FESEM and AFM analysis. From the results obtained, it can be summarized that imprinted layer composed of recognition sites were successfully formed and distributed evenly on the surface of QIM. For the binding performance evaluation, batch binding, kinetic binding and selectivity tests were conducted. The maximum binding capacity of QIM in batch binding was 25.63 mg/g, which is higher than binding capacity of NIM with the capacity value of 7.47 mg/g. Apart from that, QIM also exhibits higher adsorption rate at the initial stage of adsorption process and the saturation time was achieved after 3-4 hours contact time. Modelling of isotherm and kinetic adsorption showed that QIM has a homogenous surface and followed Elovich kinetic model, respectively. Finally, the selectivity test of QIM was investigated by using sinensetin and rosmarinic acid as competitive components. It demonstrated that QIM showed higher recognition capability towards quercetin compared to sinensetin and rosmarinic acid.