Polyamide (PA) synthetic textiles are among the most used fibers in the biomedical textile field . Wounds often provide a favorable environment for the colonization of microorganisms. In order to improve the opportunity for wound healing, it is important to create conditions that are unfavorable to microorganisms and favorable for the host repair mechanisms, and topical antimicrobial agents are believed to facilitate this process. Low-temperature plasma (plasma) is generated when a gas at low pressure and near ambient temperature is exposed to an electric field and contains radicals, ions, electrons, photons and other excited species. These species can interact either physically or chemically with the substrate surface to a depth of a few tenths of nanometers, due to their high reactivity. The advantages of plasma technology for making suitable implants or medical devices are both technological and administrative. The techniques are easy to implement, reproducible, clean and can be set up in any type of clean room. The techniques are nonpollutant, there are no organic residuals. Plasma treatment can be used to create a functionalised surface through attachment of new chemical groups. Both hydrophobic and hydrophilic surfaces can be obtained[3-7] In the present paper, we have investigated the possibility of obtaining antibacterial fabric with views on their application on dressings by using a single process, Nitrogen plasmas. Also the other modification investigated consisted of an Oxygen glow discharge pre-functionalization, followed by a two-step wet-treatment in sodium hydroxide and Nano-Titanium solutions. The surface was first activated by O2 plasma to produce more hydrophilic groups so that titanium could be coated more effectively on the surface. Different natural (wool and cotton) and synthetic (polyamide) fabrics have been treated; their surface properties have been studied by different techniques, and correlated to their antibacterial action. FTIR analysis and contact angle measurements were used to investigate the chemical nature and surface wettability of the samples following each step of the modification. FTIR analysis proved that the O2 plasma pre-functionalization of Samples reproducibly increased the amount of functional groups, including ether/alcohol, esters and carboxyl groups. Also for N2 plasma treated samples, amount of N-H groups on the samples increased. The surface morphology of samples was investigated using Scanning Electron Microscopy (SEM). The antibacterial properties were evaluated utilizing the method of plate-counting and inhibition zone of Staphylococcus aureus (gram positive) and Escherichia coli (gram negative). Our experimental results show that the N2 plasma-modified and Ti coated samples exhibits good antibacterial properties while the favorable bulk properties of samples are retained.
Journal: TechConnect Briefs
Volume: 3, Nanotechnology 2009: Biofuels, Renewable Energy, Coatings, Fluidics and Compact Modeling
Published: May 3, 2009
Pages: 210 - 214
Industry sector: Advanced Materials & Manufacturing
Topics: Coatings, Surfaces & Membranes