Study on Optical Fiber Oxygen Sensing of Fluorinated Dry Gel Sensitive Materials

In order to accurately measure the Dissolved Oxygen (DO) concentration, and enhance the sensitivity and stability of sensor head, two fluorinated dry gel oxygen sensitive materials 3, 3, 3-Trifluoropropyltrimethoxy/Tetraethyl Orthosilicate (TFP-TriMOS/TEOS) and 3, 3, 3-Trifluoropropyltrimethoxy/1, 2-Bis (triethoxysilyl) Ethane (TFP-TriMOS/BTESE) fluorinated hybrid dry gel dope with Ruthenium (Ru) complex were developed by improved sol-gel technology. Oxygen sensing head was made by dip coating plastic optical fiber into the above prepared sol-gel. Its oxygen sensing performance was studied under different precursor ratios. Experimental results show that all the fabricated DO sensing heads have good oxygen sensing performance, and the detection limits are 0.135 and 0.118 mg/L, respectively. Compared with the fiber optic oxygen sensing head coated with a single precursor (TEOS, BTESE and TFP-TriMOS), the fiber optic oxygen sensing head based on fluorinated dry gel shows higher linearity and lower detection lower limit. The stability of the fluorinated DO sensing head and the influence of pH the intensity of fluorescence signal was studied. The results show that the two kinds of fiber optic dissolved oxygen sensing head have good stability and anti-interference ability