scholarly journals Nanoencapsulated PCM slurries for the development of thermoregulating gypsums

2021 ◽  
Vol 2116 (1) ◽  
pp. 012104
Author(s):  
D López-Pedrajas ◽  
M Jiménez-Vázquez ◽  
A M Borreguero ◽  
F J Ramos ◽  
I Garrido ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Mechanical Characteristics ◽  
Weight Ratio ◽  
Good Alternative ◽  
Mechanical And Thermal Properties ◽  
Polystyrene Nanoparticles ◽  
European Regulation ◽  
Energy Storage Technology ◽  
Encapsulated Phase Change Material ◽  
Change Material

Abstract Gypsums with improved thermal properties have been obtained using a thermoregulatory nanocapsulated slurry (NPCS) as additive. In order to determine the effects of the slurries in the gypsum, physical, mechanical and thermal properties of the different composite materials (gypsum – polystyrene nanoparticles (PS) or nanocapsules (NPCM)) have been studied. Concentrated slurries from polystyrene nanoparticles without (PSS) and with encapsulated phase change material (NPCS) have been synthesized. Firstly, gypsum blocks made of nanoparticles/hemihydrate with mass ratios ranging from 0.0 to 0.42 have been produced from PSS, in order to determine the optimal weight ratio with the best mechanical/physical characteristics. Then, the thermal gypsum block from NPCM/hemihydrate has been prepared at the selected weight ratio. Although PS and NPCM addition reduces the mechanical properties, all the developed materials satisfied the mechanical European regulation EN 13279-2 which limits the mechanical characteristics of gypsums composites. The gypsum composites with PS nanoparticles presented a reduction of the thermal conductivity, so these materials can be used as insulating material. The gypsum composite with NPCM/Hem = 0.3 had an improvement in the thermal storage capacity of 88.76 % and seems to be a good alternative for applying the thermal energy storage technology in buildings.

Synthesis and Thermal Properties of Magnesium Sulfate Heptahydrate/Urea Resin as Thermal Energy Storage Micro-Encapsulated Phase Change Material

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Chenzhen Liu ◽  
Ling Ma ◽  
Zhonghao Rao ◽  
Yimin Li
Keyword(s):  
Particle Size ◽  
Thermal Properties ◽  
Phase Change ◽  
Magnesium Sulfate ◽  
Phase Change Material ◽  
Core Material ◽  
Scanning Calorimetry ◽  
Sulfate Heptahydrate ◽  
Encapsulated Phase Change Material ◽  
Change Material

In this study, micro-encapsulated phase change material (microPCM) was successfully synthesized by emulsion polymerization method, using magnesium sulfate heptahydrate (MSH) as core material and urea resin (UR) as shell material. The surface morphologies and particle size distributions of the microPCM were tested by scanning electron microscopy (SEM) and laser particle size analyzer. The chemical structure of microPCM was analyzed by Fourier-transform infrared spectroscopy (FTIR). The thermal properties were investigated by differential scanning calorimetry (DSC) and thermal conductivity coefficient instrument, respectively.

A Novel Packing Hollow Dodecahedron Model to Study the Mechanical and Thermal Properties of Stocastic Metallic Foams

2021 ◽  
Author(s):  
Rui Dai ◽  
Beomjin Kwon ◽  
Qiong Nian
Keyword(s):  
Thermal Properties ◽  
Physical Properties ◽  
Three Dimensional ◽  
Weight Ratio ◽  
High Strength ◽  
Specific Area ◽  
Deposition Process ◽  
Metallic Foam ◽  
Thermal Testing ◽  
Mechanical And Thermal Properties

Abstract Stochastic foam with hierarchy order pore structure possesses distinguished physical properties such as high strength to weight ratio, super lightweight, and extremely large specific area. These exceptional properties make stochastic foam as a competitive material for versatile applications e.g., heat exchangers, battery electrodes, automotive components, magnetic shielding, catalyst devices and etc. Recently, the more advanced hollow cellular (shellular) architectures with well-developed structure connections are studied and expected to surpass the solid micro/nanolattices. However, in terms of theoretical predicting and studying of the cellular foam architecture, currently no systematic model can be utilized to accurately capture both of its mechanical and thermal properties especially with hollow struts due to complexity induced by its stochastic and highly reticulate nature. Herein, for the first time, a novel packing three-dimensional (3D) hollow dodecahedron (HPD) model is proposed to simulate the cellular architecture. An electrochemical deposition process is utilized to manufacture the metallic foam with hollow struts. Mechanical and thermal testing of the as-manufactured foams are carried out to compare with the HPD model. HPD model is proved to accurately capture both the topology and the physical properties of stochastic foam at the similar relative density. Particularly, the proposed model makes it possible to readily access and track the physical behavior of stochastic foam architecture. Accordingly, this work will also offer inspiration for designing an efficient foam for specific applications.

scholarly journals Study the Effect of Different Percentages of Natural (Orange Peels and Date Seeds) and Industrial Materials (Carbon and Silica) on the Mechanical and Thermal Properties of Polymeric Reinforced Composites

2018 ◽  
Vol 14 (4) ◽  
pp. 16-23
Author(s):  
Haydar Abed Dahad ◽  
Sameh Fareed Hasan ◽  
Ali Hussein Alwan
Keyword(s):  
Thermal Conductivity ◽  
Composite Material ◽  
Thermal Properties ◽  
Young’S Modulus ◽  
Weight Ratio ◽  
Mechanical And Thermal Properties ◽  
Orange Peels ◽  
Industrial Materials ◽  
Flexural Tests ◽  
Natural Composite

Mechanical and thermal properties of composites, consisted of unsaturated polyester resin, reinforced by different kinds of natural materials (Orange peels and Date seeds) and industrial materials (carbon and silica) with particle size 98 µm were studied. Various weight ratios, 5, 10, and 15 wt. % of natural and industrial materials have been infused into polyester. Tensile, three-point bending and thermal conductivity tests were conducted for the unfilled polyester, natural and industrial composite to identify the weight ratio effect on the properties of materials. The results indicated that when the weight ratio for polyester with date seeds increased from 10% to 15%, the maximum Young’s modulus decreased by 54%. When the weight ratio was 5%, the maximum Young’s modulus, yield stress and ultimate tensile stress occurred in the polyester with date seeds. The results of tensile and flexural tests showed that the natural composite material has a higher strength than the industrial material. While the results of flexural tests manifested that the maximum improvement in the flexural strength is obtained for orange peels at 5 wt. %, where the maximum increasing percentage is 153.4% than pure polyester. The thermal conductivity of orange peels decreased to the half value when the weight ratio increased from 10% to 15%. The thermal conductivity for polyester with orange peels was greater than the thermal conductivity of polyester with date seeds with maximum percentage occurred at weight ratio 10% is 14.4%, but the thermal conductivity of the industrial composite material was higher than the natural composite material. Finally, the date seeds composite was a good insulator and it had a reduced heat transfer rate in comparison to the rest of the samples, also the maximum variation of temperature with time occurred in date seeds composite.

scholarly journals Development of novel biodegradable nanocomposites for bone repair applications

2021 ◽  
Author(s):  
Samin Eftekhari
Keyword(s):  
Thermal Properties ◽  
Mass Loss ◽  
Young’S Modulus ◽  
Bone Repair ◽  
Young's Modulus ◽  
Weight Ratio ◽  
Weight Fraction ◽  
Influential Factor ◽  
Mechanical And Thermal Properties ◽  
Biodegradable Nanocomposites

The main goal of this research is to introduce novel series of biodegradable nanocomposites that closely mimic the characteristics of real bone such as mechanical and thermal properties. These nanocomposites are composed of cotton-sourced cellulose microcrystals (MCC), hydroxyapatite nanoparticles (HA) and Poly L-Lactic Acid (PLLA). A novel fabrication route is used to manufacture MA and MH series of nanocomposites. MA series was developed to find an optimum range for weight fraction of each constituent required for design of the MH series. Evaluation of the thermal properties of MA series showed that increasing of weight ratio of MCC and HA from 0 to 21 Wt% increased the crystallinity up to 38%. Compression test results of them revealed that increasing the weight fraction of MCC or HA from 0 to 21Wt% enhanced the compressive yield stress from 0.127 to 2.2 MPa and the Young’s modulus from 6.6 to 38 MPa. The cytotoxicity assay results showed there was no sign of toxic material affecting on viability of cells. The MH series was designed and fabricated by selecting a narrower range of weight fraction of the constituents. A design of experiments was used to alter the composition of the constituents to assess their contributions and their effect onto the mechanical properties and biodegradation behaviour of the MH series of the nanocomposites. The weight ratio of MCC to HA, the concentration of PLLA, and the porogen content were chosen as varying factors. A model that accurately predicts the optimum parameter setting was created. Analysis of variance statistical analysis showed that the ratio of MCC to HA was the most influential factor affecting the compressive yield and the mass loss, while the porogen content was the most detrimental factor affecting the Young’s modulus of MH series of nanocomposites had no significant effect on their rate of the mass loss. The nanocomposites with highest weight ratio 4 of MCC to HA, showed maximum mechanical strength and the lowest water absorption and the lowest mass loss. It was found two series of nanocomposites was comparable to trabecular bone from a compositional, structural, thermal, mechanical point of view.

scholarly journals Hydrophilic Films Based on Carboxymethylated Derivatives of Starch and Cellulose

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2447
Author(s):  
Katarzyna Wilpiszewska ◽  
Adrian Krzysztof Antosik ◽  
Beata Schmidt ◽  
Jolanta Janik ◽  
Joanna Rokicka
Keyword(s):  
Surface Roughness ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Physicochemical Properties ◽  
Moisture Absorption ◽  
Weight Ratio ◽  
Mechanical And Thermal Properties ◽  
Film Preparation ◽  
Polysaccharide Derivatives ◽  
Derivatives Of

The carboxymethylated derivatives of starch (CMS) and cellulose (CMC) were used for film preparation. The infrared spectroscopy revealed that crosslinking via ester bridges with citric acid occurred between the two polysaccharide derivatives. The effect of polysaccharide derivatives ratio on physicochemical properties of prepared films was evaluated. Generally, the values of tested parameters (moisture absorption, surface roughness, and mechanical and thermal properties) were between the values noted for neat CMS or CMC-based films. However, the physicochemical properties of the system with equal CMS/CMC weight ratio diverged from this trend, i.e., the highest tensile strength, the highest Young’s modulus (ca. 3.4 MPa and ca. 4.9 MPa, respectively), with simultaneously the lowest moisture absorption (18.5% after 72 h) have been noted. Such systems could potentially find application in agriculture or pharmacy.

scholarly journals Preparation Adhesive Material Reinforced of Graphite Particles and Study Electrical and Mechanical and Thermal Properties

2007 ◽  
Vol 4 (3) ◽  
pp. 407-415
Author(s):  
Baghdad Science Journal
Keyword(s):  
Electrical Conductivity ◽  
Thermal Properties ◽  
Adhesion Force ◽  
Weight Ratio ◽  
Graphite Powder ◽  
Mechanical And Thermal Properties ◽  
Adhesive Material ◽  
Weight Percentage ◽  
Graphite Particles ◽  
Lap Shear

The physical, mechanical, electrical and thermal properties containing (Viscosity, curing, adhesion force, Tensile strength, Lap shear strength, Resistively, Electrical conductivity and flammability) of adhesive material that prepared from Nitrocellulose reinforced with graphite particles and aluminum streat. A comparison is made between the properties of adhesive material with varying percentage of graphite powder (0%, 25%, 30%, 35%, 40%) to find out the effect of reinforcement on the adhesive material. The ability of property an electrical was studied through the measurement of conductivity a function of temperature varying. The results of comparison have clearly shown that the increasing of content of the filler material (graphite weight) after limit ratio determined (32%) in material prepare lead to yielding the (CN) material to concept of granular agglomeration. The mechanical properties decrease when graphite weight ratio increases. Electrical conductivity and flammability increases with graphite weight percentage increases, while the electrical conductivity decreases with increases of temperature. The adherent topography of some physically tested Specimens was studied using optical microscopy.

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