Plasma Polymerization Modified Polyvinylidene Fluoride (PVDF) Membrane Development and Characterization for Degumming of Soybean Oil

Abstract

Unmodified and surface-modified polyvinylidene fluoride (PVDF) membranes were tested for their ability to degum soybean crude oil and crude oil miscellas. The membrane was modified with 1,1,1,3,3,3-hexafluoro-2-propanol or hexamethyldisiloxane (HMDSO) by radiofrequency plasma polymerization at 10-100 W glow discharge power and 1-30 min contact time. The membranes were characterized by contact angle measurements, attenuated total reflectance Fourier transform infrared spectroscopy, atomic force microscopy, and scanning electron microscopy. Modification of the PVDF membrane with HMDSO at 60 W power for 5 min increased the interfacial free energy between water and solid surface from 30 ± 2 to 64 ± 2 mJ/m 2 . This membrane was tested for permeate flux and phospholipid rejection with crude oil and different concentrations of miscella. Although formation of the polymer film on the membrane tended to decrease membrane pore size, the modified membrane had an oil flux as good as the unmodified membrane did. In addition, the modified-membrane improved the phospholipid rejection and removed 76 % of the phospholipids from the crude oil and 81-90 % of the phospholipids from crude oil miscellas.

Effects of Plasma‐Modified Polyvinylidenefluoride and Polyethersulfone Ultrafiltration (UF) Membrane Treatments on Quality of Soybean Oil

“…Details of this technique are provided in the study by Onal‐Ulusoy et al . (). This method provides reliable contact angle values for the quantification of surface free energy of a material.…”

“…Experimental setup used during membrane filtration was identical to those used in the recent study (Onal‐Ulusoy et al . ). Because crude soybean oil used in this study contains high amount of phospholipids (3.0%, Onal‐Ulusoy et al .…”

“…PVDF membrane, having an initial γ Sw value of 30 mJ/m 2 (Onal‐Ulusoy et al . ), was also modified at the same conditions as PES. Among all the modification parameters (power and time) tested, PVDF modified at 60 W for 5 min had the highest γ Sw of 64 mJ/m 2 (Onal‐Ulusoy et al .…”

“…Recently, Onal‐Ulusoy et al . () reported that polyvinylidenefluoride (PVDF) membrane modified with HMDSO at 60 W for 5 min could remove 76% and 81–90% of the phospholipids from crude soybean oil and oil‐hexane miscellas, respectively.…”

Effect of Membrane Degumming Conditions on Permeate Flux and Phospholipids Rejection

“…The main drawbacks of this process are considerable loss of neutral oil and nutrients, large amounts of wastewater and fairly large energy consumption Pagliero et al, 2001;Ulusoy et al, 2014;Sehn et al, 2016).…”