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Abstract:In this study, we successfully prepared nine non-woven, supported polyvinylidene fluoride (PVDF) membranes, using a phase inversion precipitation method, starting from a 15 wt % PVDF solution in N-methyl-2-pyrrolidone. Various membrane morphologies were obtained by using (1) PVDF polymers, with diverse molecular weights ranging from 300 to 700 kDa, and (2) different temperature coagulation baths (20, 40, and 60 ± 2 • C) used for the film precipitation. An environmental scanning electron microscope (ESEM) was used for surface and cross-section morphology characterization. An atomic force microscope (AFM) was employed to investigate surface roughness, while a contact angle (CA) instrument was used for membrane hydrophobicity studies. Fourier transform infrared spectroscopy (FTIR) results show that the fabricated membranes are formed by a mixture of TGTG' chains, in α phase crystalline domains, and all-TTTT trans planar zigzag chains characteristic to β phase. Moreover, generated results indicate that the phases' content and membrane morphologies depend on the polymer molecular weight and conditions used for the membranes' preparation. The diversity of fabricated membranes could be applied by the End User Industries for different applications.

Microencapsulation technology is being more and more applied in the textile industry because microcapsules can confer additional properties to conventional fabrics. In this context, polysulfone microcapsules containing vanillin were prepared, and their morphology, thermal stability, and antibacterial properties against Staphylococcus aureus were assessed. The microcapsules were fabricated onto 100% cotton fabrics by a coating technique. The resistance of the coating to several washing cycles was studied, and the durability of the aromatic finishing was determined. Capsules were stable in the range between 20 and 100 °C, and they inhibited the growth of the bacteria at 37 °C for, at least, one week. Most of the capsules added to the fabric were flushed away between the first and second washing cycle; however, some capsules were still observed after the fifth washing. Finally, a survey was conducted in order to know how consumers perceived the aroma, before and after several washings. Survey data was statistically analyzed, and a model was built, which allowed the probability of maintained aromatic finishing for specific washing cycles to be predicted. Thus, this work sets the basis for further development of fabrics with antimicrobial activity and pleasant aromatic finishing based on polysulfone/vanillin capsules.

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