光触媒喷涂剂抑菌性能试验研究

友田光触媒喷涂剂是廊坊市友田化工有限公司研制生产的一种新型杀抑菌材料.光触媒杀菌是通过紫外线与光触媒生成的活性氧和氢氧自由基,分解有害物质,破坏细菌细胞膜而达到杀灭细菌的效果.光触媒的作用是催化剂,参与化学反应后即还原,无残留.为了解该产品的性能,对其抑菌效果及制剂稳定性进行了研究.

纳米光触媒对棉织物理化性能的影响

将不同浓度的纳米TiO2光触媒剂采用浸轧工艺处理到棉织物上,分别用紫外线和自然光作为光源照射织物,通过测定纤维的聚合度、结晶度,以及织物的断裂强力、撕破强力、K/S值变化等,研究了纳米光触媒剂对纤维理化性能和织物颜色的影响。试验发现,经纳米TiO2处理后棉纤维的聚合度、断裂强力和撕破强力均有不同程度的下降,但结晶度和晶态结构没有显著变化。

光触媒空间型分解剂急性毒性和致突变性研究

选择SPF级ICR小鼠进行急性经口毒性试验、急性吸入毒性试验,染毒剂量与浓度分别设定为5000 mg/kg、10000 mg/m^(3)。选用家兔进行一次完整皮肤刺激试验和急性眼刺激试验,设定剂量为0.5 ml/只与0.1 ml/只家兔。皮肤变态反应试验选用48只普通级白色豚鼠,按照体质量随机分为阴性对照组、阳性对照组和实验组,雌雄各半,实验组给予诱导和激发处理,阴性对照组给予激发处理,受试物诱导和激发剂量为0.5 ml/只,阳性对照物2,4-二硝基氯苯,诱导和激发浓度分别为1%和0.1%;小鼠骨髓嗜多染红细胞微核试验选用50只SPF级ICR小鼠,雌雄各半,按体质量随机分为5000、2500和1000 mg/kg 3个剂量组,以及阴性和阳性对照组(环磷酰胺40 mg/kg)。微核试验统计分析采用双因素方差分析检验,检验水准α=0.05。结果显示,光触媒空间型分解剂小鼠急性经口半数致死量(LD50)>5000 mg/kg,急性吸入半数致死浓度(LC50)>10000 mg/m^(3),属实际无毒;对家兔皮肤和眼刺激强度属于无刺激性;对豚鼠的皮肤致敏强度未见皮肤变态反应;与阴性对照组相比,光触媒空间型分解剂各剂量组小鼠骨髓细胞微核率差异无统计学意义(P>0.05),阳性对照组细胞微核率差异有统计学意义(P<0.05)。提示光触媒空间型分解剂未见明显急性毒性和致突变性。

Experimental study and kinetic analysis of oxidant-free thermal-assisted UV digestion utilizing supported nano-TiO_2 photocatalyst for detection of total phosphorous

A novel thermal-assisted ultra-violet(UV) photocatalysis digestion method for the determination of total phosphorus(TP) in water samples was introduced in this work. The photocatalytic experiments for TP digestion were conducted using a 365 nm wavelength UV light and Ti O2 particles as the photocatalyst. Sodium tripolyphosphate and sodium glycerophosphate were used as the typical components of TP and the digested samples were then determined by spectrophotometry after phosphomolybdenum blue reaction. The effects of operational parameters such as reaction time and temperature were studied for the digestion of TP and the kinetic analysis of two typical components was performed in this paper. The pseudo-first-order rate constants k of two phosphorus compounds at different temperatures were obtained and the Arrhenius equation was employed to explain the effect of temperature on rate constant k. Compared with the conventional thermal digestion method for TP detection, it was found that the temperature was decreased from 120 °C to 60 °C with same conversion rate and time in this thermal-assisted UV digestion method, which enabled the digestion process work at normal pressure. Compared with the individual ultra-violet(UV) photocatalysis process, the digestion time was also decreased from several hours to half an hour using the thermal-assisted UV digestion method. This method will not lead to secondary pollution since no oxidant was needed in the thermal-assisted UV photocatalysis digestion process, which made it more compatible with electrochemical detection of TP.

Visible-light-promoted and photocatalyst-free trifluoromethylation of enamides

An efficient and practical method is developed for the trifluoromethylation of enamides using Umemoto's reagent as the trifluoromethylating reagent. These reactions proceeded under visible light irradiation without any photocatalyst at room temperature in good chemical yields.