Polymers have been widely used for biomedical purposes such as medical devices, tissue engineering scaffolds, and drug carriers for drug delivery system (DDS). Using polymers for such medical devices should be entirely sensible, as polymers are generally very soft, highly cost-effective, and relatively biocompatible. In order to encourage further development in the biocompatibility of the polymers for the enhanced use of the materials, the functionalization of the polymer surfaces has been deliberately introduced. Plasma modification is one of the most efficient ways for the surface treatment of polymers, since plasma treatment could selectively modify the chemical and the physical properties of the surface of the polymers by not affecting the original bulk characteristics of the polymers. Also, plasma surface modification offers shorter treatment time as compared with other surface modification methods. When plasma was applied to the polymer surface, functional groups, graft polymerization, coatings, and molecular crosslinking formation would be introduced with or without the change in the surface roughness of the polymer. The highly functionalized polymers by the plasma modifications would be effectively used for the materials in tissue engineering or drug delivery systems. In this paper, the fabrication and the characterization of polymers by several types of plasma treatments are reviewed, followed by the introduction of their applications to the materials in drug delivery systems and tissue engineering.

Surface modification of polymers by plasma treatments for the enhancement of biocompatibility and controlled drug release

Surface modification of a biomedical polyethylene terephthalate (PET) by air plasma

Perfect metamaterial absorber (PMA) can intercept electromagnetic wave harmful for body in Wi-Fi, cell phones and home appliances that we are daily using and provide stealth function that military fighter, tank and warship can avoid radar detection. We reported new concept of water droplet-based PMA absorbing perfectly electromagnetic wave with water, an eco-friendly material which is very plentiful on the earth. If arranging water droplets with particular height and diameter on material surface through the wettability of material surface, meta-properties absorbing electromagnetic wave perfectly in GHz wide-band were shown. It was possible to control absorption ratio and absorption wavelength band of electromagnetic wave according to the shape of water droplet–height and diameter– and apply to various flexible and/or transparent substrates such as plastic, glass and paper. In addition, this research examined how electromagnetic wave can be well absorbed in water droplets with low electrical conductivity unlike metal-based metamaterials inquiring highly electrical conductivity. Those results are judged to lead broad applications to variously civilian and military products in the future by providing perfect absorber of broadband in all products including transparent and bendable materials.

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Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets.

This letter reports an experimental study of a 10ns pulsed dielectric barrier discharge in atmospheric air, excited with a train of 65ns voltage pulses at a repetition frequency of 5kHz. It is shown that these ultrashort pulses produce a homogenous discharge with very high electron density in excess of 1013cm−3 and low gas temperature, which are particularly desirable for uniform treatment of thermally sensitive polymer films. Their treatment of polypropylene films is found to introduce microscale surface patterns as well as various carbon-oxygen bonds, both useful for improving the hydrophilic properties of polymeric materials.

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10 ns pulsed atmospheric air plasma for uniform treatment of polymeric surfaces

Surface modification of polylactic acid (PLA) by air atmospheric plasma treatment

Surface modification of low density polyethylene (LDPE) film by low pressure O2 plasma treatment

Characterization of the surface changes and the aging effects of low-pressure nitrogen plasma treatment in a polyurethane film

Low pressure oxygen plasma has been used to improve the surface wettability of a polyurethane film. The modifications induced by the plasma treatment in the material were analyzed using contact angle measurements. X-ray photoelectron spectroscopy technique was used for surface characterization of the plasma-treated films. Atomic force microscopy and scanning electron microscopy were used to analyze topography changes due to the plasma-etching mechanism. The results show a much better surface wettability of the film even for short exposure times, with a considerable increase in the surface energy values. As expected, functionalization with oxygen plasma is mainly because of surface oxidation with species like (CO, CO, OH, etc). An aging process with regard to polar groups rearrangement has been observed, thus promoting a partial hydrophobic recovery. Besides functionalization, the surface wettability of the material improves as a consequence of a slight increase in surface roughness because of the etching effect of oxygen plasma. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

M.R. Sanchis

Papers

Surface modification of low density polyethylene (LDPE) film by low pressure O2 plasma treatment

Characterization of the surface changes and the aging effects of low-pressure nitrogen plasma treatment in a polyurethane film

Surface modification of a polyurethane film by low pressure glow discharge oxygen plasma treatment