scholarly journals The Effects of Using Aluminum Oxide Nanoparticles as Heat Transfer Fillers on Morphology and Thermal Performances of Form-Stable Phase Change Fibrous Membranes Based on Capric–Palmitic–Stearic Acid Ternary Eutectic/Polyacrylonitrile Composite

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1785 ◽  
Author(s):  
Huizhen Ke ◽  
Yonggui Li
Keyword(s):  
Heat Transfer ◽  
Aluminum Oxide ◽  
Stearic Acid ◽  
Phase Change ◽  
Ternary Eutectic ◽  
Stable Phase ◽  
Al2o3 Nanoparticles ◽  
Aluminum Oxide Nanoparticles ◽  
Scanning Calorimetry ◽  
Fibrous Membranes

In this paper, innovative capric–palmitic–stearic acid ternary eutectic/polyacrylonitrile/aluminum oxide (CA–PA–SA/PAN/Al2O3) form-stable phase change composite fibrous membranes (PCCFMs) with different mass ratios of Al2O3 nanoparticles were prepared for thermal energy storage. The influences of Al2O3 nanoparticles on morphology and thermal performances of the form-stable PCCFMs were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and measurement of melting and freezing times, respectively. The results showed that there was no apparent leakage trace from the SEM observation. The DSC analysis indicated that the addition of Al2O3 nanoparticles had no significant effect on phase transition temperatures and enthalpies of the CA–PA–SA/PAN/Al2O3 form-stable PCCFMs. The melting peak temperatures and melting enthalpies of form-stable PCCFMs were about 25 °C and 131–139 kJ/kg, respectively. The melting and freezing times of the CA–PA–SA/PAN/Al2O310 form-stable PCCFMs were shortened by approximately 21% and 23%, respectively, compared with those of the CA–PA–SA/PAN form-stable PCCFMs due to the addition of Al2O3 nanoparticles acting as heat transfer fillers.

Regulating phase-change temperatures of form-stable phase-change ternary composite fibrous membranes consisting of polystyrene nanofibers and fatty acid eutectics via co-electrospinning method

2020 ◽  
pp. 096739112091065
Author(s):  
Huizhen Ke ◽  
Qufu Wei
Keyword(s):  
Fatty Acid ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Phase Change ◽  
Ternary Eutectic ◽  
Stable Phase ◽  
Scanning Calorimetry ◽  
Electrospinning Method ◽  
Fibrous Membranes ◽  
Composite Fibrous Membranes

The fatty acid ternary eutectics such as capric-lauric-myristic acid, capric-lauric-palmitic acid, capric-lauric-stearic acid, capric-myristic-palmitic acid, capric-myristic-stearic acid, and capric-palmitic-stearic acid and quaternary eutectics such as capric-lauric-myristic-palmitic acid, capric-lauric-myristic-stearic acid, capric-lauric-palmitic-stearic acid, capric-myristic-palmitic-stearic acid, and lauric-myristic-palmitic-stearic acid were selected as solid-liquid phase-change materials (PCMs). And then the innovative ternary eutectic/polystyrene (PS)/ternary eutectic and ternary eutectic/PS/quaternary eutectic form-stable phase-change composite fibrous membranes (PCCFMs) were directly prepared by the co-electrospinning method under the same spinning parameters. The as-prepared form-stable PCCFMs exhibited three-dimensional fibrous network structure with the average fiber diameter of about 410–780 nm according to the scanning electron microscopy images. The adhesion among nanofiber intersections was observed occasionally. The differential scanning calorimetry results showed that fatty acid eutectics have been successfully combined into the form-stable PCCFMs, and their melting peak temperatures mostly ranged from 15°C to 21°C with a temperature interval of 1°C. Moreover, the phase-change enthalpies reached about 40–61 kJ kg−1. It is concluded that these electrospun form-stable PCCFMs with appropriate phase-change temperatures could be considered as potential PCMs to be applied in thermo-regulating fibers and textiles.

Slip velocity and temperature jump of a non-Newtonian nanofluid, aqueous solution of carboxy-methyl cellulose/aluminum oxide nanoparticles, through a microtube

2019 ◽  
Vol 29 (5) ◽  
pp. 1606-1628 ◽  
Author(s):  
Marjan Goodarzi ◽  
Saeed Javid ◽  
Ali Sajadifar ◽  
Mehdi Nojoomizadeh ◽  
Seyed Hossein Motaharipour ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Aqueous Solution ◽  
Aluminum Oxide ◽  
Temperature Jump ◽  
Methyl Cellulose ◽  
Oxide Nanoparticles ◽  
Carboxy Methyl Cellulose ◽  
Aluminum Oxide Nanoparticles ◽  
Content Type ◽  
Carboxy Methyl

Purpose With respect to two new subjects, i.e. nanofluids and microchannels, in heat transfer systems and modern techniques used for building them, this paper aims to study on effect of using aluminum oxide nanoparticles in non-Newtonian fluid of aqueous solution of carboxy-methyl cellulose in microtube and through application of different slip coefficients to achieve various qualities on surface of microtube. Design/methodology/approach Simultaneously, the effect of presence of nanoparticles and phenomenon of slip and temperature jump has been explored in non-Newtonian nanofluid in this essay. The assumption of homogeneity of nanofluid and fixed temperature of wall in microtube has been used in modeling processes. Findings The results have been presented as diagrams of velocity, temperature and Nusselt Number and the investigations have indicated that addition of nanoparticles to the base fluid and increase in microtube slip coefficient might improve rate of heat transfer in microtube. Originality/value The flow of non-Newtonian nanofluid of aqueous solution of carboxy methyl cellulose-aluminum oxide has been determined in a microtube for the first time.

scholarly journals Promoting and Inhibitory Effects of Hydrophilic/Hydrophobic Modified Aluminum Oxide Nanoparticles on Carbon Dioxide Hydrate Formation

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5380
Author(s):  
Yu Liu ◽  
Xiangrui Liao ◽  
Changrui Shi ◽  
Zheng Ling ◽  
Lanlan Jiang
Keyword(s):  
Aluminum Oxide ◽  
Induction Time ◽  
Hydrate Formation ◽  
Equilibrium Temperature ◽  
Greenhouse Gas Mitigation ◽  
Al2o3 Nanoparticles ◽  
Inhibitory Effects ◽  
Aluminum Oxide Nanoparticles ◽  
Experimental Conditions ◽  
Gas Consumption

Hydrate-based CO2 capture from large emission sources is considered a promising process for greenhouse gas mitigation. The addition of nanoparticles may promote or inhibit the formation of hydrates. In this work, CO2 hydrate formation experiments were performed in a dual-cell high-pressure reactor. Non-modified, hydrophilic modified and hydrophobic modified aluminum oxide (Al2O3) nanoparticles at different concentrations were added to assess their promoting or inhibitory effects on CO2 hydrate formation. The equilibrium temperature and pressure, induction time, and total gas consumption during CO2 hydrate formation were measured. The results show that the presence of Al2O3 nanoparticles exerts little effect on the phase equilibrium of CO2 hydrates. Under the experimental conditions, the addition of all Al2O3 nanoparticles imposes an inhibitory effect on the final gas consumption except for the 0.01 wt% addition of hydrophilic modified Al2O3 nanoparticles. The induction time required for the nucleation of CO2 hydrates mainly ranges from 70 to 90 min in the presence of Al2O3 nanoparticles. Compared to the absence of nanoparticles, the addition of non-modified and hydrophilic modified Al2O3 nanoparticle reduces the induction time. However, the hydrophobic modified Al2O3 nanoparticles extend the induction time.

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