RESUMEN
According to the research achievements of phase change and humidity storage composite materials preparation in early stage, SiO2-based phase change and humidity storage composite materials were made by sol-gel method with SiO2 as the carrier and decanoic acid-palmitic acid as a phase change material in this paper. Synthetic materials in every stage of preparation process of decanoic acid-palmitic acid/SiO2 phase change and humidity storage composite materials were measured by Fourier transform infrared spectrumï¼such as phase change material preparation stage, SiO2 carrier material preparation stage and decanoic acid-palmitic acid/SiO2 phase change and humidity storage composite materials preparation stage. In the process of decanoic acid-palmitic acid/SiO2 phase change and humidity storage composite materials preparation, SiO2 network structure forming mechanism, decanoic acid-palmitic acid embed mode, chimeric mechanism of SiO2 and decanoic acid-palmitic acid were researched, respectively, in order to explain the mechanism of how to prepare decanoic acid-palmitic acid/SiO2 phase change and humidity storage composite materials by sol-gel method. Meanwhile, material composition and micro topography of decanoic acid-palmitic acid/SiO2 phase change and humidity storage composite materials were tested by X-ray diffracmeter and scanning electron microscope, so as to provide evidence about preparation mechanism of decanoic acid-palmitic acid/SiO2 phase change and humidity storage composite materials. The results showed that decanoic acid-palmitic acid is packed in a large number of closed pores or cages which were formed through breaking and restructuring of SiOSi groups; then, decanoic acid-palmitic acid/SiO2 phase change and humidity storage composite materials can be prepared based on those mentioned above. Decanoic acid-palmitic acid and SiO2 are only physical chimeric to each other, without any chemical reaction in the preparation process of decanoic acid-palmitic acid/SiO2 phase change and humidity storage composite materials. A large number of closed pores or cages are formed by SiO2 in acid-palmitic acid/SiO2 phase change and humidity storage composite materials, of which one part is used for coating decanoic acid-palmitic acid with phase change thermal control performance, and the other part is used for network space structure with humidity storage humidity control performance, in order to achieve the purpose of adjusting indoor temperature and humidity at the same time.
RESUMEN
SiO2-based phase change and humidity storage composite materials with phase change thermal control performance and humidity storage humidity control performance were made with SiO2 as the carrier and fatty acid as a phase change material. Phase change thermal control performance and humidity storage humidity control performance of SiO2-based phase change and humidity storage composite materials with different fatty acid content were tested with isothermal sorption method and cooling curve method. Composition structure of SiO2-based phase change and humidity storage composite materials were tested by Fourier transform infrared spectrum to analyze chimeric mechanism of SiO2 and fatty acid. Characteristic FTIR absorption peaks of SiO2-based phase change and humidity storage composite materials were considered as input layer; different fatty acid content of SiO2-based phase change and humidity storage composite materials, average values of absorption equilibrium moisture content and desorption equilibrium moisture content of SiO2-based phase change and humidity storage composite materials with relative humidity as 52.89%, and cooling time from 30 to 15 â of SiO2-based phase change and humidity storage composite materials were seen as output layer respectively; S activation function was treated as hidden layer; then, optimization performance forecast model of SiO2-based phase change and humidity storage composite materials with structural parameters and phase change and humidity storage comprehensive performance was established by back-propagation neural network. The results showed that SiO2 and fatty acid are only physical chimeric to each other, while there is no chemical reaction between them. SiO2-based phase change and humidity storage composite materials by adding in 0.079 mol fatty acid has the best phase change and humidity storage comprehensive performance, that is, absorption equilibrium moisture content is 0.132 3 g·g-1, desorption equilibrium moisture content is 0.147 5 g·g-1, average value of equilibrium moisture content is 0.139 9 g·g-1 when relative humidity is 52.89%, cooling time from 30 to 15 â is 1 305 s. Optimization performance forecast model of SiO2-based phase change and humidity storage composite materials are proved well with good accuracy, and the relative error of predicted data and experimental data are -2.07% and 2.45%, respectively; forecast model can be used for optimizing forecast phase change thermal control performance and humidity storage humidity control performance of SiO2-based phase change and humidity storage composite materials.
RESUMEN
A total of 29 novel sulfenamide compounds were synthesized, spectroscopically characterized and evaluated in vitro for antimicrobial activity against various infectious pathogens. Compounds 1b and 2c exhibited potent inhibition against clinical Methicillin-resistant Staphylococcus aureus (MRSA) strains with minimum inhibitory concentration (MIC) values of 1.56 µg/mL.
