We examine the potential of organic phase change material (PCM) gel and organic PCM gel-in-water emulsion as heat storage materials. The organic PCM gel was retained even after the phase change of organic PCM from solid to liquid phase above melting point of organic PCM. The fluidity of organic PCM gel-in-water emulsion remained unchanged even after the phase change of organic PCM from liquid to solid phase below melting point of organic PCM. Furthermore, the heat storage capability of organic PCM gel and organic PCM gel-in-water emulsion were higher than that of organic PCM alone.
We developed an educational material with which the crystal form and color property of hybrid sulfate double salt crystal growing from solution can be selected by chemical composition of precursor material of the hybrid sulfate double salt crystal. A pale pink color (L*＝83.64, a*＝0.26, b*＝－0.57) radial crystal grows from precursor ([K2Mg(SO4)2-6H2O]:[K2Mn(SO4)2-4H2O]＝50:50) and a pale red color (L*＝76.54, a*＝13.38, b*＝0.39) radial crystal grows from precursor ([K2Mn(SO4)2-4H2O]:[K2Co(SO4)2-6H2O] ＝75:25). Then a pale red color (L*＝76.54, a*＝13.38, b*＝0.39) block crystal, a pale green color (L*＝87.34, a*＝－0.64, b*＝－1.00) block crystal, and a pale blue color (L*＝86.21, a*＝－0.27, b*＝－0.95) block crystal grow from precursor ([K2Mg(SO4)2- 6H2O]:[K2Co(SO4)2-6H2O]＝99:1), ([K2Mg(SO4)2-6H2O]:[K2Ni(SO4)2-6H2O]＝99:1), and ([K2Mg(SO4)2-6H2O]:[K2Cu(SO4)2-6H2O] ＝99:1) respectively.
The Femtoreactor is a smart technology that can control chemical processes in an ultra-small droplet of several micrometers (volume of femto-liter level) prepared by electrospray. This makes the precise control of chemical processes possible based on the obvious increase in the speed of mixing of two solutions and separation of products. This is applicable to the synthesis of metal nanoparticles of single nano size with a narrow distribution. The application of the Femtoreactor with electrospray in a liquid medium gave an insight into the control of various chemical processes.
Large reduction in solar power generation cost is essential to utilize sunlight as one of the basic energy resources for social activities. In this light, there is a growing attention to organic photovoltaics and hybrid solar cells developed with novel materials and new structures. Colloidal quantum dots(CQDs) are promising absorbers for the solar cells because the absorption band can be tuned to cover a wider range of solar spectrum. In this paper, current situation of in QDC-based solar cells is reviewed. Recent our results on PbS CQD solar cells with ZnO nanowire arrays are also reported.
Preparation of nano-structured silica materials using molecular assemblies formed by surfactants as “structure directing agents (SDA)” is described. First, preparation of mesoporous silica particles with controlled pore size and structure using aqueous mixtures of anionic and cationic surfactants as SDA is introduced. Next, silica hollow particles with size around 30 nm and highly dispersible in water are prepared using vesicles formed by cationic surfactant mixtures as SDA and applied for anti-reflection films. Furthermore, silica nanotubes are successfully prepared using myelin figures formed by Pluronic type surfactants as SDA. Finally, the mechanism of morphological changes in SDAs accompanying the sol/gel reaction of silica precursors is discussed based on the obtained results.