Milatz Roland, Duvigneau Joost, Vancso Gyula Julius
Department of Materials Science and Technology of Polymers, and Department of Sustainable Polymer Chemistry, University of Twente, Enschede 7522 NB, The Netherlands.
DPI, P.O. Box 902, 5600 AX Eindhoven, The Netherlands.
ACS Appl Mater Interfaces. 2023 Jul 19;15(28):34023-34030. doi: 10.1021/acsami.3c05124. Epub 2023 Jul 1.
Nonpolar materials like polyolefins are notoriously challenging substrates for surface modification. However, this challenge is not observed in nature. Barnacle shells and mussels, for example, utilize catechol-based chemistry to fasten themselves onto all kinds of materials, such as boat hulls or plastic waste. Here, a design is proposed, synthesized, and demonstrated for a class of catechol-containing copolymers (terpolymers) for surface functionalization of polyolefins. Dopamine methacrylamide (DOMA), a catechol-containing monomer, is incorporated into a polymer chain together with methyl methacrylate (MMA) and 2-(2-bromoisobutyryloxy)ethyl methacrylate (BIEM). DOMA serves as adhesion points, BIEM provides functional sites for subsequent "grafting from" reactions, and MMA provides the possibility for concentration and conformation adjustment. First, the adhesive capabilities of DOMA are demonstrated by varying its content in the copolymer. Then, terpolymers are spin-coated on model Si substrates. Subsequently, the atom transfer initiator (ATRP) initiating group is used to graft a poly(methyl methacrylate) (PMMA) layer from the copolymers, with 40% DOMA content providing a coherent PMMA film. To demonstrate functionalization on a polyolefin substrate, the copolymer is spin-coated on high-density polyethylene (HDPE) substrates. A POEGMA layer is grafted from the ATRP initiator sites on the terpolymer chain on the HDPE films to provide antifouling characteristics. Static contact angle values and Fourier transform infrared (FTIR) spectra confirm the presence of POEGMA on the HDPE substrate. Finally, the anticipated antifouling functionality of grafted POEGMA is demonstrated by observing the inhibition of nonspecific adsorption of the fluorescein-modified bovine serum albumin (BSA) protein. The poly(oligoethylene glycol methacrylate) POEGMA layers grafted on 30% DOMA-containing copolymers on HDPE show optimal antifouling performance exhibiting a 95% reduction of BSA fluorescence compared to nonfunctionalized and surface-fouled polyethylene. These results demonstrate the successful utilization of catechol-based materials for functionalizing polyolefin surfaces.
像聚烯烃这样的非极性材料是出了名的难以进行表面改性的基材。然而，在自然界中并未观察到这种挑战。例如，藤壶壳和贻贝利用基于儿茶酚的化学方法将自身附着在各种材料上，如船体或塑料垃圾。在此，提出、合成并展示了一类用于聚烯烃表面功能化的含儿茶酚共聚物（三元共聚物）的设计。含儿茶酚的单体多巴胺甲基丙烯酰胺（DOMA）与甲基丙烯酸甲酯（MMA）和甲基丙烯酸2-(2-溴异丁酰氧基)乙酯（BIEM）一起被引入聚合物链中。DOMA作为粘附点，BIEM为后续的“接枝生长”反应提供功能位点，而MMA为浓度和构象调整提供了可能性。首先，通过改变其在共聚物中的含量来证明DOMA的粘附能力。然后，将三元共聚物旋涂在模型硅基板上。随后，使用原子转移引发剂（ATRP）引发基团从共聚物上接枝聚（甲基丙烯酸甲酯）（PMMA）层，含40% DOMA的共聚物可形成连续的PMMA膜。为了证明在聚烯烃基材上的功能化，将共聚物旋涂在高密度聚乙烯（HDPE）基材上。从HDPE膜上三元共聚物链上的ATRP引发剂位点接枝聚（寡聚乙二醇甲基丙烯酸酯）（POEGMA）层以提供防污特性。静态接触角值和傅里叶变换红外（FTIR）光谱证实了HDPE基材上存在POEGMA。最后，通过观察荧光素修饰的牛血清白蛋白（BSA）蛋白非特异性吸附的抑制情况，证明了接枝的POEGMA预期的防污功能。接枝在HDPE上含30% DOMA的共聚物上的聚（寡聚乙二醇甲基丙烯酸酯）POEGMA层表现出最佳的防污性能，与未功能化和表面污染的聚乙烯相比，BSA荧光降低了95%。这些结果证明了成功利用基于儿茶酚的材料对聚烯烃表面进行功能化。
