Fabrication of a Hydrophilic Low-Friction Poly(hydroxyethyl methacrylate) Coating on Silicon Rubber

Abstract

Silicon rubber has been widely used in the biomedical field due to its excellent mechanical properties and physiological inertia. However, the hydrophobic properties of silicon rubber surfaces limit their further application. Therefore, constructing a silicon rubber coating with hydrophilic and low-friction surface properties would be highly significant. Existing methods to achieve such coatings, including grafting polymer brushes and the deposition of hydrophilic materials, suffer from several deficiencies such as complicated coating processes and insufficient coating firmness. In this paper, we report a hydrophilic polymer poly­(hydroxyethyl methacrylate) (PHEMA) coating that can easily coat the surface of silicon rubber to provide low-friction performance. Sample silicon rubber was treated with benzophenone and hydroxyethyl methacrylate monomer solution in turn. The as-prepared coating was characterized by infrared spectroscopy, X-ray photoelectron spectroscopy, white light interference, and MFT-5000 wear test. The results indicated that the PHEMA coating had excellent hydrophilic properties (with a low contact angle of 9.39°) compared to uncoated silicon rubber. As the concentration of glycerol in the monomer solution was increased, the thickness and surface roughness of the as-prepared coating gradually decreased. The coating was firmly adsorbed on the substrate, and it had a zero-class bonding strength. In addition, the as-prepared coating demonstrated good friction-reduced properties, with the coefficient of friction being reduced by 98.0% compared with the uncoated silicon rubber in simulated blood. In summary, a hydrophilic and low-friction coating was successfully prepared using a simple method, and the results reported herein provide valuable insight into the surface design of similar soft materials.

Fabrication and Characterization of Polyelectrolyte Coatings by Polymerization and Co-Deposition of Acrylic Acid Using the Dopamine in Weak Acid Solution

“…The main chain of the PDMS structure is alternately connected by silicon and oxygen, and the side chain is composed of methyl groups. 38 The peaks at 800, 1260 � , and 2960 cm −1 are attributed to Si−CH 3 stretching vibration absorption, Si−CH 3 twisting deformation vibration absorption, and CH 3 asymmetric stretching vibration absorption, respectively, and the peak at 1020 and 1074 cm −1 attributed to the asymmetric stretching of Si−O−Si (Figure 1A). 43 The stretch vibration absorption peaks of −OH and −NH appear on the PDA coating and PDA/PAA coating surface at 3380 and 1620 cm −1 (Figure 1B), and they are not found on the PDMS surface.…”

“…Figure A,B shows the infrared spectrum of the surface of original PDMS, PDA coating, and PDA/PAA coating. The main chain of the PDMS structure is alternately connected by silicon and oxygen, and the side chain is composed of methyl groups . The peaks at 800, 1260  , and 2960 cm –1 are attributed to Si–CH 3 stretching vibration absorption, Si–CH 3 twisting deformation vibration absorption, and CH 3 asymmetric stretching vibration absorption, respectively, and the peak at 1020 and 1074 cm –1 attributed to the asymmetric stretching of Si–O–Si (Figure A) .…”

“…Coating roughness and thickness were characterized using the white light interferometer (MFP-D, Rtec, USA). The coating thickness was obtained by measuring the height difference between the coating and the substrate using the step method . The surface wettability of the coatings was measured by means of the JC2000CS contact angle meter (Powereach, China).…”

“…The coating thickness was obtained by measuring the height difference between the coating and the substrate using the step method. 38 The surface wettability of the coatings was measured by means of the JC2000CS contact angle meter (Powereach, China). The droplet volume was 2 μL each time, and three points were randomly tested on each sample to obtain the average value.…”

Bioinspired Phosphorylcholine Coating for Surface Functionalization of Interventional Biomedical Implants with Bacterial Resistance and Anti-Encrustation Properties

“…Several surface modification methods of polymeric materials have been employed to enhance lubrication between implanted biomedical devices and soft tissues. − Among different modification strategies, the application of a lubrication coating on the surface can efficiently reduce the friction associated with biomedical devices. For example, Peng et al reported the development of a multifunctional zwitterionic coating made by sulfobetaine/active ester block copolymers via controlled reversible addition–fragmentation chain transfer polymerization, which could be covalently grafted on the surface of silicone rubber and lead to improved lubrication.…”