Simultaneous graft copolymerization of 2‐hydroxyethyl methacrylate and acrylic acid onto polydimethylsiloxane surfaces using a two‐step plasma treatment

Abstract

Acrylic acid (AAc) and 2-hydroxyethyl methacrylate (HEMA) mixtures were simultaneously grafted onto the surfaces of polydimethylsiloxane (PDMS) films using a two-step oxygen plasma treatment (TSPT). The first step of this method includes: oxygen plasma pretreatment of the PDMS films, immersion in HEMA/AAc mixtures, removal from the mixtures, and drying. The second step was carried out by plasma copolymerization of preadsorbed reactive monomers on the surfaces of dried pretreated films. The effects of pretreatment and polymerization time length, monomer concentration, and ratio on peroxide formation and graft amount were studied. The films were characterized by attenuated total reflection Furrier transformer infrared (ATR-FTIR) spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), zeta potential, surface tension, and water contact angle measurements. The ATR-FTIR spectrum of the modified film after alkaline treatment showed the two new characteristic bands of PHEMA and PAAc. Both increase the polar part of surface tension (g p ) after grafting and the evaluation of surface charge at pH 1.8, 7, and 12 confirmed the presence of polar groups on the surface of grafted films with a mixture of HEMA/AAc. Morphological studies using both AFM and SEM evaluation illustrated various amounts of grafted copolymer on the surface of PDMS films.

Plasma modified surfaces for covalent immobilization of functional biomolecules in the absence of chemical linkers: towards better biosensors and a new generation of medical implants

“…Plasma treatment has been successful, for example, in modifying the hydrophobic surface of polydimethylsiloxane (PDMS) to make it hydrophilic and suitable for conventional derivations for biomaterials (Karkhaneh et al 2007).…”

One-step surface modification of poly(dimethylsiloxane) by undecylenic acid

“…The approach by Mizadeh et al [28] was adapted where 1 mM potassium chloride was used as a background electrolyte in all experiments. 0.1 M potassium hydroxide and 0.1 M hydrochloric acid was used for pH adjustment.…”

Biomimetic modification of silicone tubes using sodium nitrite–collagen immobilization accelerates endothelialization

“…2,3 A widely used surface modification method is plasma graft polymerization of acrylic acid (AAc), which introduces functional carboxyl groups on an inert silicone surface. [4][5][6][7] Nowadays, biomimetic coatings incorporating bioactive molecules that can be bound successfully to the carboxyl groups of AAc, such as collagen and gelatin, 4,6 insulin, 8 and anticoagulants such as thrombodulin, 9 albumin, 10 and heparin 9,11,12 are extensively used. AAc-grafted materials show improved wettability, [4][5][6][7] but they negatively affect many cell types when in direct contact.…”

“…[4][5][6][7] Nowadays, biomimetic coatings incorporating bioactive molecules that can be bound successfully to the carboxyl groups of AAc, such as collagen and gelatin, 4,6 insulin, 8 and anticoagulants such as thrombodulin, 9 albumin, 10 and heparin 9,11,12 are extensively used. AAc-grafted materials show improved wettability, [4][5][6][7] but they negatively affect many cell types when in direct contact. 4,6 On the other hand, covalent immobilization of collagen onto AAc-grafted materials, through chemical bonds between amino groups of collagen and carboxyl functional groups of AAc, enhances cell adhesion, proliferation, and differentiation.…”