Papers by Keyword: Plasma Polymerisation

Abstract: Bacterial contamination of biomedical devices is an ongoing problem. One method to alleviate such contamination is the introduction of surface compounds onto devices which can kill bacteria on contact. Polymers containing quaternary ammonium groups are known for their antimicrobial properties. Here we report a substrate-independent two-step method for the immobilisation of quaternary ammonium groups onto any type of surface. To achieve this glycidlytrimethylammonium chloride was covalently bound to plasma polymerised allylmine interlayer. Changes in the membrane permeability of Escherichia coli were observed by BacLight LIVE\DEAD staining. 30% of E. coli grown on the treated surfaces showed high levels of membrane permeability within 4 hours. Importantly, there was no observable cytotoxic effect on human dermal fibroblasts.

Abstract: This paper compares proton diffusion through plasma-polymerised proton-exchange membranes (PEMs) produced using traditional wet-chemical methods (Nafion®) and those produced using plasma-polymerisation. Using quasielastic neutron scattering and a simple model of proton motion we find the measured diffusion-rate of protons in the plasma-polymerised material and Nafion® is the same (within 1 standard error) even though the plasma-polymerised membrane has 80 % less water than the Nafion®. We attribute this result to the highly cross-linked structure of the plasma-polymerised membrane.

Abstract: Terpinen-4-ol is the main constituent of Melaleuca alternifolia essential oil known for its biocidal and anti-inflammatory properties. The possibility of fabricating polymer thin films from terpinen-4-ol using radio frequency (RF) plasma polymerisation for the prevention of the growth of Pseudomonas aeruginosa was investigated, and the properties of the resultant films compared against their biologically active precursor. Films fabricated at 10 W prevented bacterial attachment and EPS secretion, whilst polyterpenol films deposited at 25 W demonstrated no biocidal activity against the pathogen.

Abstract: In the present work, technique of plasma polymerization was used to generate amido (- NH2) and carboxyl (-COOH) on titanium surface for immobilizing bovine serum albumin (BSA). After plasma polymerization of allylamine and crylic acid, the contact angle with respect to double distilled water significantly increased. Surface components were detected by X-ray photoelectron spectroscopy and Fourier transform infrared reflection-absorption spectroscopy. The results showed that BSA was successfully immobilized on the titanium surface and the amounts of BSA on specimens were relied on the properties of thin film deposited through plasma polymerization, which was corresponding to the ultraviolet spectrophotometer result.

Abstract: Deposition of thin plasma polymer films as final layer on organic coatings can provide one promising solution to tailor the surface properties offering third functionality and increased mechanical properties. The present work is dedicated to the study of the barrier properties of polyurethane coil coatings modified by different plasma polymerization processes. Microwave (MW) and radio frequency (RF) plasmas were used to deposit thin films with different composition from various precursor mixtures. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) were used to reveal the evolution of the plasma treated coil coatings during weathering tests. Electrochemical impedance spectroscopy (EIS) was employed to study the barrier properties of the coatings. The results show a degradation effect of the plasma treatment on the barrier properties of the coil coatings especially in the case of the oxygen-containing plasmas. However addition of a fluorinecontaining component to the precursor mixture leads to the elimination of the negative effect of the plasma treatment on the barrier properties of the coil coatings. The fluorine-containing films exhibit higher weathering stability in comparison with the fluorine-free ones.