A Nano-SiO2 Form-Stable Phase Change Material for Building Thermal Energy Conservation

2012 ◽  
Vol 442 ◽  
pp. 81-86
Author(s):  
Wei Jun Lin
Keyword(s):  
Fatty Acid ◽  
Phase Change ◽  
Lauric Acid ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Stable Phase ◽  
Differential Scanning Calorimetric ◽  
Stable Form ◽  
Gravimetric Analysis ◽  
Time Service

A stable form-phase change materials (PCM), based on capric-lauric acid eutectic served as the absorption material and the support of nano-silica material to prepare by sol-gel method. The best ratio capric-lauric acid eutectic combination is determined for 60 wt. %. Capillarity because of the influence of the hydrogen bonding, fatty acid and eutectic can be fixed in the three dimensional network structure of the construction of the silicon atom bonds and O still so solid sample melting point composite heating more fatty acid eutectic. Form and chemical properties of the composite phase change the transmission electron microscope, semi and Fourier transform infrared method.- Differential scanning calorimetric hot method is used for measuring phase transition temperature and phase change of latent heat composite, value 19.57 and 71.28 J/g , respectively. At the same time, service performance and other composite material thermal stability and thermal conductivity coefficient test using thermo gravimetric analysis and transient hotline method, respectively.

scholarly journals Diffusion of Shape Stabilized PEG-SiO2 as a Driver for Producing Thermoregulating Facing Bricks

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1395
Author(s):  
Angel Serrano ◽  
Ana M. Borreguero ◽  
Isabel Iglesias ◽  
Anselmo Acosta ◽  
Juan F. Rodríguez ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Sol Gel ◽  
Effective Diffusion ◽  
Gelation Time ◽  
Stable Phase ◽  
Liquid Form ◽  
Indoor Temperature ◽  
Adsorption Capacities ◽  
Change Material

A novel form-stable phase-change material (PCM) based on facing bricks was developed by incorporating thermoregulating PEG-SiO2, synthetized by sol-gel method and based on polyethylene glycol as phase-change material and silica as stabilizer compound. The PEG-SiO2 in its liquid form (sol) is firstly adsorbed inside the porous brick and lastly stabilized (gel) by controlling its gelation time, obtaining form-stable PCMs with PEG-SiO2 contents within 15–110 wt.%. Kinetic adsorption curves of the sol into bricks having different porosities as well as maximum adsorption capacities were obtained. The effective diffusion coefficients (Deff) were estimated by means of Fick’s second law, it being possible to predict the adsorption of sol PEG-SiO2 by the brick as function of its porosity and the free diffusion coefficient. Finally, form-stable PCMs demonstrated an improvement in their thermal energy storage capacity (up to 338%), these materials being capable of buffering the indoor temperature during an entire operational day

Effect of Annealing Temperature on Phase Transition of Nanoalumina Synthesized by Auto-Combustion Route

2016 ◽  
Vol 41 ◽  
pp. 74-86 ◽  
Author(s):  
Muhammad Adil ◽  
Hasnah Mohd Zaid ◽  
Kean Chuan Lee ◽  
Noor Rasyada Ahmad Latiff
Keyword(s):  
Phase Transition ◽  
Particle Size ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Amorphous State ◽  
Specific Area ◽  
Combustion Method ◽  
Gravimetric Analysis ◽  
Crystalline Phases ◽  
Auto Combustion

Nanocrystalline Al2O3 powder has been successfully synthesized by a simple and fast sol-gel auto-combustion method. The transformation of crystalline phases of as-synthesized nano powders was investigated through X-ray diffraction in terms of their crystallinity and crystallite size. Subsequently, a detailed transmission electron microscopy (TEM) investigation, including specific area electron diffraction (SAED) analysis revealed the crystallographic alterations and morphological information even at lattice scale which co-include the XRD analysis. The results obtained allow to explain the evolution of an amorphous state into different crystalline phases with increased calcining temperature; and their relation to particle size. The particle size is found to be closely related to phase transition of Al2O3 from γ → δ → θ → κ →α. The existence of distinctive bonds and band energy were studied by employing Fourier-transform infrared spectroscopy (FTIR) and UV-visible spectroscopy, respectively. On the other hand, thermo gravimetric analysis (TGA) had also been performed to confirm the phase purity of nano powder.

Lauric acid/bentonite/flake graphite composite as form-stable phase change materials for thermal energy storage

2020 ◽  
Vol 10 (2) ◽  
pp. 214-224 ◽  
Author(s):  
Songyang Liu ◽  
Jie Han ◽  
Qingjie Gao ◽  
Wenze Kang ◽  
Ruichen Ren ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Lauric Acid ◽  
Stable Phase ◽  
Impregnation Method ◽  
Flake Graphite ◽  
Graphite Composite

The main purpose of this paper was to synthesize a novel form-stable composite phase change material (PCM). Herein, bentonite-based PCMs were synthesized by impregnating Na-bentonite clay with lauric acid (LA) through a vacuum impregnation method. Flake graphite (FG) was used to enhance the thermal conductivity of the composite PCMs. In addition, FG also helped block the leakage of the PCMs. It is worth noting that with the addition of FG, the period of melting and solidifying of composite PCMs were decreased to some extent. Meanwhile, the thermal conductivity of the PCMs has been obviously improved. Moreover, the synthesized composite PCM exhibited a favorable performance of reliability after 200 thermocycling test. Hence, this study showed that the developed composite PCM has the potential to be applied in thermal energy storage systems.

Form-stable phase change material based on fatty acid/wood flour composite and PVC used for thermal energy storage

2020 ◽  
Vol 209 ◽  
pp. 109663 ◽  
Author(s):  
Xing Jingchen ◽  
Yang Keyan ◽  
Zhou Yucheng ◽  
Yu Yuxiang ◽  
Chang Jianmin ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Wood Flour ◽  
Stable Phase ◽  
Change Material

scholarly journals Irradiation of a Nanocomposite of Pseudoboehmite-Nylon 6,12

2010 ◽  
Vol 71 ◽  
pp. 28-33 ◽  
Author(s):  
Antônio Hortêncio Munhoz Jr. ◽  
Renato Meneghetti Peres ◽  
L.H. Silveira ◽  
Leonardo Gondim Andrade e Silva ◽  
L.F. de Miranda
Keyword(s):  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Mechanical Tests ◽  
Polymeric Matrix ◽  
Nano Particles ◽  
Gravimetric Analysis ◽  
Polymeric Nanocomposites ◽  
X Ray Diffraction ◽  
Inorganic Substances ◽  
Sol Gel Process

Nanocomposites are nanometrical material particles embedded in a specific matrix. The degree of organization of the nanostructures and their properties depend on the nature of the organic and inorganic components of the structure that can generate synergic interactions. Polymeric nanocomposites are related to a class of hybrid materials where inorganic substances of nanometric dimensions are dispersed in a polymeric matrix. In the present work, nanocomposites of nylon 6,12 with different concentrations of pseudoboehmite obtained by sol-gel process were prepared with and without the presence of octadecylamine. After preparation, the samples were irradiated with a 200 kGy radiation dose in an electron accelerator. The pseudoboehmite nano particles were characterized by X-ray diffraction, scanning electron microscopy, differential thermal analysis and thermo gravimetric analysis. The nanocomposites were characterized by thermal and mechanical tests. The addition of pseudoboehmite promoted a reduction of the melting flow during the production of the composites evidencing the interaction of pseudoboehmite with the polymeric matrix, probably modifying its crystalline structure.

Lauric acid/intercalated kaolinite as form-stable phase change material for thermal energy storage

Energy ◽  
2014 ◽  
Vol 76 ◽  
pp. 385-389 ◽  
Author(s):  
Shaokun Song ◽  
Lijie Dong ◽  
Yang Zhang ◽  
Shun Chen ◽  
Qi Li ◽  
...  
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Lauric Acid ◽  
Stable Phase ◽  
Change Material

Structural, Thermal and Optical Properties of PVP Capped ZnO Films

2013 ◽  
Vol 678 ◽  
pp. 253-257 ◽  
Author(s):  
Thangaraj Pandiyarajan ◽  
B. Karthikeyan
Keyword(s):  
Optical Properties ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
Emission Spectra ◽  
Hexagonal Wurtzite Structure ◽  
Zno Films ◽  
Band Edge Emission ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Absorption Measurements

In the present work we report, synthesis, structural, thermal and optical properties of ZnO incorporated PVP films. To prepare Polyvinylpyrolidone (PVP) capped ZnO films, simple room temperature sol gel method was adopted. Prepared PVP capped ZnO films were annealed at 800 C for 15 min and 30 min. X ray diffraction pattern shows prepared particles are in hexagonal wurtzite structure. Optical absorption measurements show an exciton absorption peak around ~ 370 nm. Emission spectra shows strong peaks around 329 and 333 nm are attributed to the band edge emission and broad peak found at 432 nm is attributed to the defect related emission. Thermal properties of the prepared films were studied by thermo gravimetric analysis. Interaction between the ZnO nanoparticles and PVP were investigated by Fourier Transform Infrared Spectroscopy (FTIR), it shows band at 441 cm-1 is attributed to Zn-O bond.

Doping of Palladium in Silica Nanofibers via Electrospinning and Sol-Gel Synthesize as Hydrogen Storage Material

2011 ◽  
Vol 471-472 ◽  
pp. 1040-1045 ◽  
Author(s):  
Samaneh Shahgaldi ◽  
Zahira Yaakob ◽  
Dariush Jafar Khadem ◽  
Wan Ramli Wan Daud ◽  
Edy Herianto Majlan
Keyword(s):  
Hydrogen Storage ◽  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
Thermo Gravimetric Analysis ◽  
High Surface Area ◽  
Chemical Vapour ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Silica Nanofibers

In recent years, one dimensional nanostructure, nanowires, nanofibers with unique properties have been a subject of intense research due to reduction of devise dimension, potential properties from the re-arrangement at the molecular level and high surface area. There are many methods for synthesize such as laser ablation, chemical vapour deposition, solution method micro pulling down method but all these method faced to the major disadvantages of being complicated with long wasting time and relatively high expense . The electrospinning recently used for producing ceramic, metal, and carbon nanofibers. In this report, we incorporate palladium into silica nanofibers for the first time, and the effect of doping of palladium into the silica nanofibers is investigated. The different ratio of palladium to silica and comparing with silica nanofibers is also reported. The composition, morphology, structure and surface area of silica, and silica palladium nanofibers were investigated by thermo gravimetric analysis (TGA), x-ray diffraction (XRD), scanning electron microscopy (SEM),Fourier transform infrared spectroscopy (FT-IR), and Micromeriics. To the best of our knowledge, investigation on characteristic on Silica palladium nanofibers has not been reported up to now. The result reveal that the silica nanofibers compare to silica doped with palladium have lower diameter, and also by increasing the temperature above 600 °C, the reduction in length of nanofibers happened. High surface area of silica palladium nanofibers can be one of the promising materials for hydrogen storage.

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