PBST/TiO_(2)/MgO复合薄膜的制备及性能

采用硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)对TiO_(2)/MgO NPs改性,采用溶液共混法制备了聚丁二酸-共-对苯二甲酸丁二醇酯(PBST)/TiO_(2)/MgO NPs纳米复合薄膜,并探讨了其在食品包装方面的应用。研究了改性TiO_(2)/MgO NPs对PBST基体机械、阻隔、抗菌和保鲜性能的影响。结果表明:复合膜的抗拉强度和水蒸汽透过率分别为29.39MPa和2.43×10^(-11) g·m/(m^(2)·s·Pa),相较PBST基体抗拉强度提高了24.32%,水蒸汽透过率降低了32.37%,且对金黄色葡萄球菌(S.aures)和大肠杆菌(E.coli)抑菌效果显著,分别达到98.7%和97.2%,并对圣女果有良好的保鲜性能,当改性后的TiO_(2)/MgO NPs质量含量为5%时,复合薄膜的性能最佳。

Evaluation of Particle Properties of MgO/TiO2 Material by Monte Carlo Simulation Method

The simulation by the Monte Carlo method executed by the software PyPENELOPE proved effective to specify the particle propagation characteristics by calculating the absorption fractions, backscattering and transmission of electrons and secondary photons under the incidence of 0.5 to 20 KeV range of primary electrons. More than 99.9% of the primary electrons were transmitted in the 125 nm thick MgO/TiO2 material at 20 KeV. This occurred because several interactions took place in the transmitted primary irradiation such as characteristic, fluorescence, and bremsstrahlung produced when of the occupation of the KL3, KL2, KM3, and KM2 shell and sub-shell of titanium and magnesium which are the elements with a high atomic number in the material. The transmission particle characteristic of this material is therefore an indicator capable of improving the electrical performance and properties of the sensor.

TiO2/MgO共掺对99氧化铝瓷结构和微波介电性能的影响

采用无压烧结,在1550℃制备了TiO2/MgO共掺99氧化铝瓷。研究了不同比例的TiO2/MgO共掺对99氧化铝瓷的致密化、微观结构和微波介电性能的影响。研究发现:在共掺总量为1wt%的条件下,不同TiO2/MgO掺杂所得的99氧化铝瓷均为单一刚玉相;TiO2/MgO比例的提高有利于促进99氧化铝瓷的致密化、晶粒长大、介电常数εr的提高和介电损耗tanδ的降低;当TiO2/MgO为0.8 wt%/0.2 wt%时,99氧化铝瓷的密度可达3.88 g/cm^3,介电常数εr可达9.90,tanδ约为0.0003。