Phthalocyanine functionalized poly(vinyl alcohol)s via CuAAC click chemistry and their antibacterial properties

Abstract: In this article, the new zinc phthalocyanine (ZnPc)-based poly(vinyl alcohol)s (PVA-Pcs) are synthesized by copper(I)-catalyzed azide-alkyne cycloaddition click reaction (CuAAC) between azide side chain functionalized PVA (PVA-N₃) and alkyne substituted ZnPc (Pc-Al), and characterized. The structure of PVA-Pcs and their intermediates are determined by a combination of Fourier-transform infrared (FTIR) and proton nuclear magnetic resonance (¹H-NMR) spectroscopies. On the other hand, the effect of Pc-Al loading by mole (PVA-N₃:Pc-Al = 10:1 and 10:2) on the wettability, thermal and antibacterial properties of achieved final products is investigated, utilizing water contact angle (WCA) measurements, thermogravimetric (TGA) and differential scanning calorimetry (DSC) analyses, and antibacterial activity tests, respectively. Based on the WCA, TGA, and DSC analyses of PVA-Pcs, it is found that utilizing a higher loading of Pc-Al in the CuAAC reaction medium enhances the WCA and thermal properties of resulted products. Furthermore, the antibacterial activity tests against both Gram negative bacteria (Escherichia coli and Salmonella typhimurium) and Gram positive bacteria (Staphylococcus aureus and Listeria monocytogenes) revealed the higher inhibition effect of PVA-Pcs compared to neat PVA, some prevalent antibiotics and control samples. Thus, PVA-Pcs are promising materials that can be used in different application areas requiring lower wettability and higher thermal and antibacterial properties. Graphic abstract: [Figure not available: see fulltext.].