Uniform TitleStatic and dynamic adsorption of ?-lactoglobulin on polymeric membrane surface and development of novel membranes by surface modification
NameKim, Jun Tae (author), Liu, Sean (chair), Huang, Qingrong (co-chair), Daun, Henryk (internal member), Simon, Lee (outside member), Rutgers University, Graduate School - New Brunswick,
Proteins--Absorption and adsorption
DescriptionThe protein adsorption on polymeric membrane surface is the major factor to cause the membrane fouling in ultrafiltration (UF) processing to concentrate, fractionate, and separate whey proteins from liquid whey which is byproduct of cheese manufacturing process. Membrane fouling, which is defined as the decrease of the filtration performances such as permeation flux, efficiency, and selectivity is still one of the major problems encountered in many food industries employing membrane separation processing. In order to better understand fouling mechanism, to optimize the process condition to minimize fouling, and to develop the novel membranes to reduce fouling, the protein adsorption on the polymeric membrane surface was studied by static adsorption and dynamic adsorption experiments.
From the static adsorption experiment, the adsorption capacity and the surface heterogeneity of ?-lactoglobulin were determined at various conditions of the protein solution by an adsorption isotherm. Dynamic adsorption process was studied by QCM-D, which allows monitoring of the protein adsorption process in real time by simultaneously measuring of frequency shift (?f) and dissipation shift (?D).
To develop the novel membranes to reduce the protein adsorption and fouling, two surface modification methods were developed by hydrophilic polymers grafting using UV/Ozone treatment and thin film composite (TFC) through interfacial polymerization. The hydrophilic polymer grafted membranes might reduce the hydrophobic interactions between protein and membrane surface by improve the hydrophilicity of the polymeric membrane. UV/Ozone is one of the powerful techniques to initiate and activate the polymeric membrane surface to graft the hydrophilic polymers. Interfacial polymerization has been a well established way to prepare the thin active layer by a polycondensation reaction in two immiscible phases (organic solvent and water phase). Dense and thin polyamide layer can be formed on the polymeric membrane surface. The hydrophilic polymers such as PVA, PEG, and chitosan were modified on the polyamide thin layer to improve the hydrophilicity of the modified membranes. Some surface properties of modified PES membranes were characterized by contact angle, FT-IR, XPS, and AFM. These results proved that PES membranes were modified successfully with hydrophilic polymers and showed more hydrophilic property and lower protein adsorption.
NoteIncludes bibliographical references (p. 151-159).
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
RightsThe author owns the copyright to this work.