Polyampholytic Poly(AEMA-co-SPMA) Thin Films and Their Potential for Antifouling Applications

Abstract

Polyampholytic poly­(2-aminoethyl methacrylate-co-sulfopropyl methacrylate) (p­(AEMA-co-SPMA)) thin films were prepared by self-initiated photopolymerization and photografting (SIPGP) and are demonstrated to be a potential alternative to films prepared from zwitterionic poly­(sulfobetaine methacrylate) (pSBMA) for antifouling applications. SIPGP allows polymerization from aqueous solutions containing only monomers, implying that p­(AEMA-co-SPMA) thin films can be prepared simply and inexpensively without the risk of introducing potentially toxic substances necessary in many controlled polymerization reactions. For the polymers, wettabilities were studied by contact angle goniometry, the compositions of the films were determined by infrared and X-ray photoelectron spectroscopies, and streaming current measurements were used to assess their net charge. The antibiofouling properties were compared via adsorption of fibrinogen and bovine serum albumin, settlement of algal zoospores, and the growth of sporelings of the marine alga Ulva lactuca. The fouling of the p­(AEMA-co-SPMA) copolymer was in several respects similar to that of the zwitterionic pSBMA and suggests that it is potentially suitable for applications under high-salinity conditions, such as marine or physiological environments.

Tailoring Diffusional Fields in Zwitterion/Dopamine Copolymer Electropolymerized at Carbon Nanowalls for Sensitive Recognition of Neurotransmitters

“…The reason is that, in functionalized electrodes, the XPS signal is gathered from the incorporated C–O catechol and C–N amines, rather than from surface C–O–C bonds. Moreover, in the case of the BCNW|PDA|PZ, there is also a possible contribution of C–S bonds of the sulfobetaine unit in this range. − In the hybrid coating, the signal corresponding to the π–π satellite peak plummets, presumably because SBMA units constitute a large portion of the coating. Since they have π bonds only in methacrylate groups, PZ does not contribute to the conjugated system of π bonds and the π–π signal is diminished.…”

“…Long-term exposure showed that the amperometric response was maintained for 5 days (254 ± 39 μA cm –2 ) and started to decrease after the sixth day. This behavior can be ascribed to the protective role of zwitterion preventing the adsorption of albumins. ,, …”

“…This behavior can be ascribed to the protective role of zwitterion preventing the adsorption of albumins. 8,12,59 Intermolecular Interaction between Zwitterion and Dopamine. This section is devoted to the elucidation of the intermolecular interactions between the zwitterion (SBMA) incorporated into the PDA structure and the analyte, dopamine (DA).…”

Structure and pH-Induced Swelling of Polymer Films Prepared from Sequentially Grafted Polyelectrolytes

“…24 In these films, the second layer was grafted as a thickness gradient on top of a bottom layer of homogeneous thickness, using self-initiated photografting and photopolymerization (SI-PGP), 27 which is a simple and robust method for creating polymer thin films from methacrylate monomers 28 and which has been useful for the preparation of antifouling coatings. 10,29,30 Fouling studies conducted on such sequentially grafted bilayer gradients have shown that resistance to nonspecific protein adsorption is optimal when the layer is charge-compensated, which is dependent on the pH and the location along the gradient. 24,25 The charge equilibrium also coincides with a collapsed state of the polymer, leading to the unexpected observation that the most collapsed film is the most fouling-resistant, as opposed to nominally neutral polymers that are most fouling-resistant in the swollen state.…”

“…24,25 The charge equilibrium also coincides with a collapsed state of the polymer, leading to the unexpected observation that the most collapsed film is the most fouling-resistant, as opposed to nominally neutral polymers that are most fouling-resistant in the swollen state. 31 While the utility of coatings prepared in this manner is demonstrated in the literature, 10,29,30,32 further insights into the grafting and film formation are required to fully exploit this method. Correlating the antifouling properties to the swelling and the composition of the film at a given pH would allow for the development of coatings with switchable antifouling or pHcontrollable cleaning functions.…”