Microplasma copolymerization of amine and Si containing precursors

We report a technique of microplasma copolymerization for depositing a stable amino functional film on the inner walls of a glass microcapillary. The monomers ethylenediamine (EDA), 3 aminopropyltriethoxysilane (APTS) and hexamethyldisiloxane (HMDSO) were used as organic precursors for copolymerization. The ratio of the monomer mixture in the plasma was precisely fed using an original technique of liquid injection and helical mixing. The coatings obtained from EDA-HMDSO were found to be more stable than those produced using EDA and APTS. The films were characterized using X-ray photoelectron, Fourier transform infrared and UV-vis spectroscopy, atomic force microscopy and growth rate measurements. The hydrophobic and hydrophilic characteristics of the films were analyzed through water contact angle and surface free energy measurements. The stability of the coatings formed using this method in aqueous media indicated that they could be utilized for biological and microfluidic applications.