Penghibridan Bahan Sol-gel dan Kitosan sebagai Matriks untuk Bahan Penderia Kimia

This study focused on the development and optimization of a hybrid materialfonnedfrom sol-gel and chitosan which could be used as a chemical sensing material. It is hoped that this new matrix can overcome certain weaknesses in solgel and chitosan materials. Dip-coating technique was used to prepare the film on microscope glass slide which functioned as a solid support. For optimization purposes, thymol blue was chosen as a pH indicator and was entrapped in the film. The film was characterized using uv-Visible Spectrophotometer. Morphology studies of the suiface of the film werecarried out using Scanning Electron Microscope (SEM). Results indicated that the most suitable sol-gel:chitosan ratio for hybridfonnation was 60:40 after considering the surface morphology of the film, leaching, response time and also the intensities of the spectrum. Besides that, the results also show that the pH indicator could be successfully entrapped inside the hybrjdfilm and would still retain its chemical behavior just as in solution. The sensing material was found to have good repeatability when reacted with buffer solution and showed RSD values of 4.24 % and 5.96 % in buffer solution at pH 2.0 and pH 11.0, respectively. The entrapped indicator also showed good photo stability with RSD of 5.35% for the duration of 8 hours. However, the reproducibility of the hybridfilm was quite low with a RSD value of 18.40 % and 31.22 % at wavelength of 500 nm and 600 nm, respectively due to leaching.