Water-Wettable Polypropylene Fibers by Facile Surface Treatment Based on Soy Proteins

Publication year: 2013
Authors: Salas C. 1,3, Genzer J. 2, Lucia L.A 1, Hubbe A.M. 1, Rojas O.J. 1,2, 4

† 1 - Department of Forest Biomaterials and 2 - Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
3 - Department of Chemical Engineering, Universidad de Los Andes, Mérida 5101, Venezuela
4 - School of Chemical Technology, Department of Forest Products Technology, Aalto University, 00076 Aalto, Finland

Published in: ACS Applied Materials & Interfaces, 2013, Vol. 5, p. 6541 − 6548
doi: dx.doi.org/10.1021/am401065t

Modification of the wetting behavior of hydrophobic surfaces is essential in a variety of materials, including textiles and membranes that require control of fluid interactions, adhesion, transport processes, sensing, etc. This investigation examines the enhancement of wettability of animportant class of textile materials, viz., polypropylene (PP) fibers, by surface adsorption of different proteins from soybeans, including soyflour, isolate, glycinin, and β-conglycinin. Detailed investigations of soy adsorption from aqueous solution (pH 7.4, 25 ° C) on polypropylene thin films is carried out using quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). A significant amount of protein adsorbs on to the PP surfaces primarily due to hydrophobic interactions. We establish that adsorption of a cationic surfactant, dioctadecyldimethylammonium bromide (DODA) onto PP surfaces prior to the protein deposition dramatically enhances its adsorption. The adsorption of proteins from native (PBS buffer, pH 7.4, 25 ° C) and denatured conditions (PBS buffer, pH 7.4,95 ° C) onto DODA-treated PP leads to a high coverage of the proteins on the PP surface as confirmed by a significant improvement in water wettability. A shift in the contact angle from 128 ° to completely wettable surfaces ( ≈ 0 ° ) is observed and confirmed by imaging experiments conducted with fluorescence tags. Furthermore, the results from wicking tests indicate that hydrophobic PP nonwovens absorb a significant amount of water after protein treatment, i.e., the PP-modified surfaces become completely hydrophilic.

MP-SPR keywords: hydrophilic, hydrophobic, polypropylene nonwovens, protein adsorption, surface modification, textiles, wettability