刺激响应型过氧化氢凝胶的制备与性能

Preparation and Properties of Responsive Hydrogen Peroxide Gel with Silicon Dioxide as Gelator

通过低温震荡方法制备了过氧化氢凝胶。研究了微米和纳米级颗粒状二氧化硅对过氧化氢的胶凝行为及其所形成凝胶的刺激响应性。用R/S软物质测定仪研究了某过氧化氢凝胶配方的触变性能。结果表明,二氧化硅的粒度与表面性质直接影响其胶凝能力,亲水性纳米二氧化硅比亲水性微米二氧化硅具有更好的胶凝能力,而疏水性微米和纳米二氧化硅不能胶凝过氧化氢。亲水性纳米二氧化硅的过氧化氢凝胶具有显著的温度/剪切双重刺激响应性,并随过氧化氢浓度的增加而增强。在实验的基础上,提出了凝胶形成和刺激触变的可能机理。实验发现,加入微量表面活性剂与氢氟酸,能够有效提高凝胶的稳定性。

The H2O2 gels were successfully prepared by vibrating at low temperature. The gelling behavior and stimuli-responsiveness of H2O2 gel with SiO2 micro/nano particles as gelators were studied. The thixotropic property of some H2O2 gel has been studied using the R/S soft-solid tester. The results show that both the size and the surface properties of the SiO2 particles employed affect their gelation ability significantly, and the hydrophilic SiO2 nano-particles have stronger gelling abilities than hydrophilic SiO2 micro-particles hydrophobic SiO2 micro/nano particles can not gel H2O2. The H2O2 gel with the hydrophilic SiO2 nano-particle as a gelator prepared exhibits great temperature- or shear sensitive properties. The higher the concentration of H2O2 in the gel, the greater the responsiveness of the gel to the stimuli. On the bases of the experimental studies, a model for the explanation of the gelation and the gel stimuli responsive properties was proposed. In addition, It was also found that the addition of small amount of surfactant or HF can improve the stability of the gel significantly.