Efficient detection of volatile aromatic hydrocarbon using linseed oil–styrene–divinylbenzene copolymer coated quartz crystal microbalance
A polymer film with high sensing ability in QCM for benzene, toluene, o-xylene and ethyl benzene vapors has been produced from the co-polymerization of styrene, divinyl benzene and linseed oil with an optimum ratio at 120 °C using benzoyl peroxide as the initiator in an argon atmosphere. The cross linked polymers are used as sensing films on the surface of a silver coated quartz crystal microbalance sensor. The films of the sensors are developed by a simple solution dip-dry method using a precursor solution followed by polymerization. The chemical composition of the polymer is optimized for the maximum sensor response of 30 μl linseed oil–40 μl styrene–30 μl divinyl benzene (w/w) for all the analytes. Linear calibration curves are obtained for all the vapors in the concentration range from 5 ppm to 250 ppm and sensitivities are found to be approximately 1.1 to 1.7 Hz per ppm. The structure and surface morphology of the copolymer are analyzed by FTIR and FESEM. Surface morphologies and surface roughness of the sensing film before and after exposure to analytes are confirmed by AFM microscopy. The sensors are reactivated by desorption of analytes from the sensor surface by continuous flow of dry nitrogen gas into the sensor chamber. The sensing ability of the polymer film is few times more than other reported materials. The film has no similar sensitivity with phenols and other polar aromatic derivatives.