纳米颗粒的超临界干燥法制备及用于醋酸乙烯蒸气的催化发光检测

Determination of Vinyl Acetate Vapor Utilizing Cataluminescence on Nanoparticles Prepared by Supercritical Fluid Drying

利用乙醇超临界流体干燥技术(SCFD)(280℃×7.0MPa×30min)制备了纳米MgO及Y2O3颗粒,发现其对一些有害气体的催化发光强度远高于普通干燥技术制备的纳米MgO及Y2O3。设计了一种以SCFD技术合成的纳米MgO为敏感材料,催化发光检测醋酸乙烯蒸气的传感器。此传感器具有很高的灵敏度及优异的选择性,在温度279℃、波长425nm、空气流速为160mL/min的最佳条件下,催化发光强度与醋酸乙烯蒸气浓度在1.8～1800mg/m3内呈良好的线性关系,检出限为0.7mg/m3。当浓度相同的丙酮、乙醛、乙酸乙酯、乙酸、甲醛、氨水、乙醇、苯和甲醇蒸气通过此传感器时,除乙醇引起3.56%的干扰外,其它气体基本不干扰醋酸乙烯的测定。应用本方法可快速测定车间空气中的醋酸乙烯。

MgO and Y2O3 nanoparticles were prepared by supercritical fluid drying （SCFD） method （280 ℃×7.0 MPa×30 min）. It was found that the cataluminescence （CTL） intensities of some harmful gases on MgO-SCFD and Y2O3-SCFD nanoparticles were much higher than those on nanoparticles prepared by common drying （CD） method. A CTL sensor using MgO-SCFD as the sensing material was developed for the detection of vinyl acetate vapor. The proposed sensor showed high sensitivity and selectivity to vinyl acetate under the optimal conditions of temperature of 279 ℃, wavelength of 425 nm and flow rate of 160 mL/min. The linear range of CTL intensity versus concentration of vinyl acetate vapor was 1.8-1800 mg/m3, with detection limit of 0.7 mg/m3. Under the optimized conditions, None or only very low levels of significant interference were observed while the foreign substances such as acetone, acetaldehyde, ethyl acetate, acetic acid, formaldehyde, ammonia, ethanol, benzene and methanol were passing through the sensor. This method allows rapid determination of vinyl acetate in air at workshop.