Effect of Preparation Ways on Structure and Properties of Steraric Acid/Na+-Montmorillonite Phase-Change Composite Materials

2012 ◽  
Vol 501 ◽  
pp. 589-592
Author(s):  
Hui Xia Feng ◽  
Han Zheng ◽  
Yi Wang
Keyword(s):  
Phase Change ◽  
The Other ◽  
Fusion Process ◽  
Structure And Properties ◽  
Release Experiment ◽  
Ft Ir ◽  
The Stability ◽  
Change Material ◽  
Scanning Electron ◽  
Better Than

Two different methods, heat fusion process and solution infusion process had been used to synthesize a kind of phase change material (PCM) for latent heat thermal energy storage (LHTES). The composite was composed by steraric acid (SA) and montmorillonite (MMT). The morphology of the SA/MMT was characterized by scanning electron microscope (SEM) and FT-IR. The thermal performance and stability of the composite was characterized by differential thermal scanners (DSC) and heating store/release experiment. The FT-IR results demonstrated the PCMs and MMT combined by only physical bonds, SEM results showed that SA was intercalated in to MMT, and heat fusion process was contribute to the combination better than the other. The heating store/release experiment indicated that the stability of M-SA/MMT is better than S-SA/MMT.

Comparison of Stratification in a Water Tank and a PCM-Water Tank

2007 ◽  
Author(s):  
A. Castell ◽  
C. Sole´ ◽  
M. Medrano ◽  
M. Nogue´s ◽  
L. F. Cabeza
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Temperature Change ◽  
High Energy ◽  
Hot Water ◽  
The Other ◽  
High Energy Density ◽  
Water Tank ◽  
Charging And Discharging Processes ◽  
Change Material

Most of the storage systems available on the market use water as storage medium. Enhancing the storage performance is necessary to increase the performance of most systems. The stratification phenomenon is employed to improve the efficiency of storage tanks. Heat at an intermediate temperature, not high enough to heat up the top layer, can still be used to heat the lower, colder layers. There are a lot of parameters to study the stratification in a water tank such as the Mix Number and the Richardson Number among others. The idea studied here was to use these stratification parameters to compare two tanks with the same dimensions during charging and discharging processes. One of them is a traditional water tank and the other is a PCM-water (a water tank with a Phase Change Material). A PCM is good because it has high energy density if there is a small temperature change, since then the latent heat is much larger than the sensible heat. On the other hand, the temperature change in the top layer of a hot water store with stratification is usually small as it is held as close as possible at or above the temperature for usage. In the system studied the Phase Change Material is placed at the top of the tank, therefore the advantages of the stratification still remain. The aim of this work is to demonstrate that the use of PCM in the upper part of a water tank holds or improves the benefit of the stratification phenomenon.

Developing a thermo-regulative system for nonwoven textiles using microencapsulated organic coconut oil

2020 ◽  
pp. 152808372092149
Author(s):  
Saraç E Gözde ◽  
Öner Erhan ◽  
Kahraman M Vezir
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Coconut Oil ◽  
Nonwoven Fabric ◽  
Scanning Calorimetry ◽  
Microencapsulated Phase Change Material ◽  
Nonwoven Textiles ◽  
Composite Fabrics ◽  
Change Material ◽  
Scanning Electron

Organic coconut oil was investigated as a bio-based phase change material in core, and melamine formaldehyde was used as shell material to fabricate microencapsulated phase change material for thermo-regulation in nonwoven textiles. The microcapsules were synthesized using in situ polymerization method. The produced microcapsules (microencapsulated phase change material) were applied by knife coating in different ratios (1:5 and 1.5:5; MPCM: coating paste by wt.) to 100% polypropylene nonwoven, porous, and hydrophilic layer of a laminated, spunbond, and double-layer fabric. The coated layer was confined within two layers of the fabric to develop a thermo-regulative system on the nonwoven fabric to regulate the body temperature in surgeries. The two layers were composed by applying heat (140°C) and pressure (12 kg/cm2). Organic coconut oil, the fabricated microcapsule, and the composite fabrics were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. Scanning electron microscopy results revealed that spherical and uniform microcapsules were obtained with an approximate particle size of 2–6 µm. Differential scanning calorimetry results indicated that microencapsulated phase change material and the composite fabrics possessed significant melting enthalpies of 72.9 and 8.4–11.4 J/g, respectively, at peak melting temperatures between 21.6 and 22.8°C within human comfort temperature range. The utilization of coconut oil as a phase change material and the composite integration of this phase change material to a nonwoven fabric bring forward a novelty for future applications.

The Experimental Research on the Thermal Properties of Shape-Stabilized Phase Change Materials

2013 ◽  
Vol 291-294 ◽  
pp. 1159-1163
Author(s):  
Quan Ying Yan ◽  
Li Hang Yue ◽  
Li Li Jin ◽  
Ran Huo ◽  
Lin Zhang
Keyword(s):  
Thermal Stability ◽  
Fatty Acid ◽  
Phase Change ◽  
Phase Change Materials ◽  
Liquid Paraffin ◽  
Capric Acid ◽  
Good Thermal Stability ◽  
Change Material ◽  
Thermal Stability Of ◽  
Better Than

This paper investigated the thermal performance of shape stabilized phase change paraffin and shape-stabilized phase change fatty acid. And the PCMs are mixtures of 60% 46# paraffin and 40% liquid paraffin, 65 % 48# paraffin and 35% liquid paraffin,30%capric acid and 70% lauric acid, 30%capric acid and 70% myristic acid. Support material is high-density polyethylene. The results in this paper show that: Thermal stability of both of the two types of phase change materials are good, thermal stability of shape stabilized phase change fatty acid is better than that of paraffin. Results in this paper can provide references and basis for the application of phase change material walls in the practice building.

Studies on the synthesis, characterization and application of a novel copolymer macromonomer for polymeric solidsolid phase change materials

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Peng Xi ◽  
Xiao-hua Gu ◽  
Bowen Cheng
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Phase Change Materials ◽  
Solid Phase ◽  
The Novel ◽  
Structure And Properties ◽  
Crystal Properties ◽  
Polymeric Solid ◽  
Vinyl Group ◽  
Change Material

AbstractA novel copolymer as a macromonomer with a polyethylene glycol (PEG) unit as the phase change element and a vinyl group was synthesized for the preparation of polymeric solid-solid phase change materials. The IR, 1HNMR, DSC and WAXD and POM were employed to determine the structure and properties of the novel monomer. The results show that the novel monomer possess steady molecular structure, excellent crystal properties, higher phase change enthalpy and reactivity. Furthermore, the novel polymeric solid-solid phase change material was also prepared via the copolymerization of the novel copolymer macromonomer and styrene. The phase change properties of the polymeric solid-solid phase change material were characterized.

The Preparation and Assessment of the Rigid Aerogel Insulation Composites

2012 ◽  
Vol 512-515 ◽  
pp. 301-305
Author(s):  
Rui Xiang Liu ◽  
Tang Yin Cui ◽  
Chang Ling Zhou ◽  
Chong Hai Wang ◽  
Yan Yan Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Tensile Strength ◽  
Constant Pressure ◽  
Composite Ceramic ◽  
The Other ◽  
Ft Ir ◽  
Coefficient Of Heat Conductivity ◽  
Scanning Electron

The hydrophobic aerogel heating-insulating composite ceramic was fabricated in the way of constant pressure. The properties of the ceramic were attributed through FT-IR and energy spectrum. The microstructure and phase transformation of the insulation composites ceramic was characterized by scanning electron microscopy. The results show that after compositing with aerogel the coefficient of heat conductivity of the heat-insulating ceramic decreases forty-sixty percent and the compressive strength increases a hundred percent. There is little change to the tensile-strength. The holes of the ceramic are full of aero gel particles whose grain size is ten-twenty μm and the distribution of pore size is ten-seventy nm. After heating at 400°C for 12 minutes by quartz lamp on the surface of the ceramic which the thick of it is 8mm, the temperature of the other side increases 10°C .When the thick of the ceramic is 16mm, the temperature of the other side remains unchanged. The ceramic has excellent heating-insulting property.

Properties of a Solid–Solid Phase Change Material PAN/SA-LA/ZMS

2014 ◽  
Vol 703 ◽  
pp. 3-8 ◽  
Author(s):  
Jing Guo ◽  
Xiang Kang You ◽  
Li Zhang ◽  
Heng Xue Xiang ◽  
Sen Zhang ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Solid Phase ◽  
The Novel ◽  
Structure And Properties ◽  
Scanning Calorimetry ◽  
Solution Blending ◽  
Blending Process ◽  
Change Material ◽  
Insulating Properties

In this study, novel solid–solid phase change materials (PCM) composed of polyacrylonitrile, binary of fatty acids ((blending of stearic acid (SA) and lauric acid (LA)) and zeolite molecular sieve (ZMS) were prepared by solution blending process. The structure and properties of the PCM were characterized using flourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), polarized optical microscopy (POM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TG), respectively. DSC analysis indicated that the crystallization latent heat of the PCM was 125.22 J/g and its phase transition temperature was about 17 °C. The temperature curve for step cooling of the PCM showed that it’s holding time achieved 1 480 s, which explains that the PCM had excellent heat-insulating properties. Based on all results it can be concluded that the novel PCM can be considered as potential PCM for thermal energy storage.

Redoping Effects on Structure and Properties of Coaxial Polyaniline/Carbon Nanotube Nanocomposites

2014 ◽  
Vol 692 ◽  
pp. 352-355
Author(s):  
Yi Zhou ◽  
Wen Yi Li ◽  
Qing Wu Tian ◽  
Da Jun Zhang
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Hydrochloric Acid ◽  
Oxidative Polymerization ◽  
Structure And Properties ◽  
Chemical Oxidative Polymerization ◽  
Multiwalled Carbon ◽  
Ultrasonic Assisted ◽  
Scanning Electron ◽  
Better Than

Coaxial polyaniline/multiwalled carbon nanotubes (MWCNTs) nanocomposites were prepared by ultrasonic–assisted chemical oxidative polymerization of aniline monomers in hydrochloric acid solution, in which MWCNTs with minimal defects was used as a template. Redoping of hydrochloric acid was achieved after the as-prepared nanocomposites were treated by ammonia. The nanocomposites were characterized by field emission scanning electron microscopy, fourier transform infrared spectroscopy, thermogravimetric analysis and cyclic voltammetry, respectively. The results indicated that HCl doped nanocomposites were better than HCl redoped nanocomposites on the thermal stability and electrochemical properties.

Structure and Properties of Cotton Grafted Using Trifluoroethyl Methacrylate via ATRP Method

2013 ◽  
Vol 796 ◽  
pp. 364-369
Author(s):  
Shi Wei Li ◽  
Tie Ling Xing ◽  
Zhan Xiong Li ◽  
Guo Qiang Chen
Keyword(s):  
Cotton Fabric ◽  
Breaking Strength ◽  
Water Repellency ◽  
Structure And Properties ◽  
Elongation At Break ◽  
Significant Difference ◽  
Surface Contact Angle ◽  
Ft Ir ◽  
Water Repellence ◽  
Better Than

In this work, cotton was grafted with trifluoroethyl methacrylate (TFEMA) via atom transfer radical polymerization (ATRP) in water aqueous. The appearance of the cotton fabric was characterized with SEM, and SEM of the grafted cotton displayed significant difference from the ungrafted cotton. FT-IR indicated that TFEMA was successfully grafted onto surface of cotton fibers. Surface contact angle test and water repellency rating test showed that the water repellence of the modified cotton fabric were better than the ungrafted cotton fabric. Compared with the ungrafted cotton fabric, the whiteness, air permeability, breaking strength and elongation at break of the grafted cotton fabric decreased slightly. Grafted treatment led to efficient implantation of fluorine atoms on the surface of cotton fabric, this resulted in water repellence without altering the bulk properties of the cotton fabric.

Mangnese Dioxide Nano-Crystal as Catalyst to Remove Formaldehyde

2011 ◽  
Vol 298 ◽  
pp. 147-152 ◽  
Author(s):  
Wei Shao ◽  
Xiu Juan Chu ◽  
Kai Gao ◽  
Hua Zhang
Keyword(s):  
Hot Spot ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Formaldehyde Oxidation ◽  
Nano Crystal ◽  
Liquid Precipitation ◽  
Scanning Electron ◽  
Better Than

The purification technology and material of indoor formaldehyde is a hot spot in the field of material at present. In this paper, MnSO4, KMnO4, NaOH and H2O2 etc. are used to make manganese dioxide nanocrystal with the method of liquid precipitation. X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and properties. The results show that the products are nano-crystals of γ- MnO2 and δ-MnO2. The catalyze oxidation of formaldehyde using bothγ- MnO2 and δ-MnO2 as catalysts was investigated; and acetyl acetone method was used to characterize formaldehyde chroma. The catalytic ability ofγ-MnO2 nanocrystal to catalyze formaldehyde oxidation is better than that ofδ-MnO2.

Review on Phase Change Material Slurries

2013 ◽  
Vol 860-863 ◽  
pp. 946-951
Author(s):  
Jie Chen ◽  
Feng Jiao Liu ◽  
Yi Fei Zheng
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Apparent Specific Heat ◽  
Heat Transfer Capacity ◽  
Change Material ◽  
Better Than

Phase change materials (PCM) have recently received considerable attention in the field of thermal energy storage, due to their intrinsic properties. Phase change material slurry is a novel medium of heat storage and transfer, its apparent specific heat and heat transfer capacity is better than water.PCM slurries are being investigated for active thermal energy storage or as alternatives to conventional single phase fluids because they are pumpable and have advanced heat transport performance with phase change. This review mainly presents the information on PCM emulsions and microencapsulated PCM slurries (mPCM slurries).

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