The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Selahattin Yilmaz - One of the best experts on this subject based on the ideXlab platform.
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esterification of Cetyl Alcohol with palmitic acid over wo3 zr sba 15 and zr sba 15 catalysts
Applied Catalysis A-general, 2016Co-Authors: Vahide Nuran Mutlu, Selahattin YilmazAbstract:Abstract Tungsten loaded and Zr incorporated SBA-15 catalysts (WO 3 /Zr-SBA-15 and Zr-SBA-15) were developed for esterification of Cetyl Alcohol and palmitic acid. The influence of the Zr content, tungsten loading amount, calcination temperature, feed composition and catalyst amount has been studied. Higher tungsten loading decreased the acidity due to formation of WO 3 crystals whereas calcination temperature enhanced the acidity by favoring the dispersion of WO x species. Activities of the catalyst changed depending on their amount of Bronsted sites and total number of acid sites. Zr-SBA-15 catalyst which had the highest amount of Bronsted acid sites gave maximum Cetyl palmitate yield (63.1%). This catalyst retained its activity up to 3 reuse cycles without significant loss of activity.
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Esterification of Cetyl Alcohol with palmitic acid over WO3/Zr-SBA-15 and Zr-SBA-15 catalysts
Applied Catalysis A: General, 2016Co-Authors: Vahide Nuran Mutlu, Selahattin YilmazAbstract:Abstract Tungsten loaded and Zr incorporated SBA-15 catalysts (WO 3 /Zr-SBA-15 and Zr-SBA-15) were developed for esterification of Cetyl Alcohol and palmitic acid. The influence of the Zr content, tungsten loading amount, calcination temperature, feed composition and catalyst amount has been studied. Higher tungsten loading decreased the acidity due to formation of WO 3 crystals whereas calcination temperature enhanced the acidity by favoring the dispersion of WO x species. Activities of the catalyst changed depending on their amount of Bronsted sites and total number of acid sites. Zr-SBA-15 catalyst which had the highest amount of Bronsted acid sites gave maximum Cetyl palmitate yield (63.1%). This catalyst retained its activity up to 3 reuse cycles without significant loss of activity.
A. Sreekumar - One of the best experts on this subject based on the ideXlab platform.
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cold thermal energy storage with lauryl Alcohol and Cetyl Alcohol eutectic mixture thermophysical studies and experimental investigation
Journal of energy storage, 2020Co-Authors: Nadiya Philip, Raam G Dheep, A. SreekumarAbstract:Abstract The surging demand for thermal energy storage (TES) directs considerable attention towards the development of phase change materials (PCMs). This study has the objective to develop a eutectic PCM for effective cold thermal energy storage. The work involves preparation, thermophysical property analysis and experimental studies of a novel binary eutectic mixture. The technique of Differential Scanning Calorimetry is used in determination of thermophysical properties of the prepared eutectic. Results show that the 80:20 eutectic composition of lauryl Alcohol and Cetyl Alcohol with melting temperature of 20.01 °C and latent heat of 191.63 J g−1 is fit for use in cold thermal energy storage. The material also proves to have good thermal conductivity. Thermal stability and reliability studies which are carried out using accelerated thermal cycling tests and thermo gravimetric analysis provide positive reports for the new mixture. An experimental investigation on the effectiveness of the identified PCM is carried out by using it in a cold storage chamber. Experimental studies report a solid improvement in cold energy containment of the PCM incorporated storage chamber resulting in considerable energy savings.
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preparation thermophysical studies and corrosion analysis of a stable capric acid Cetyl Alcohol binary eutectic phase change material for cold thermal energy storage
Energy technology, 2018Co-Authors: C. Veerakumar, A. SreekumarAbstract:This paper focuses on the preparation, thermo-physical properties studies and corrosion analysis of a stable capric acid/ Cetyl Alcohol as eutectic phase change material (PCM) for the application of thermal comfort of buildings. Differential scanning calorimetry is used to investigate the thermal properties of the prepared eutectic PCM and the result shows that the eutectic composition of 70% capric acid and 30% Cetyl Alcohol was suitable for low temperature thermal energy storage with melting and freezing temperature of 22.89 oC and 11.97 oC respectively. The latent heats of melting and freezing of the eutectic PCM are 144.92 J g-1 and 145.85 J g-1. The changes in melting point and latent heat of the eutectic mixtures over continuous charging/discharging cycles were presented. The accelerated thermal cycling test and Fourier transform infrared spectroscopy studies showed that the prepared eutectic PCM has good thermal stability over 1000 thermal cycles. Also, corrosion compatibility test for copper, aluminium and stainless steel 316 metal samples with the prepared eutectic PCM were also discussed and recommendations for using it in the operational environment were presented.
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Preparation, Thermophysical Studies, and Corrosion Analysis of a Stable Capric Acid/Cetyl Alcohol Binary Eutectic Phase Change Material for Cold Thermal Energy Storage
Energy Technology, 2018Co-Authors: C. Veerakumar, A. SreekumarAbstract:This paper focuses on the preparation, thermo-physical properties studies and corrosion analysis of a stable capric acid/ Cetyl Alcohol as eutectic phase change material (PCM) for the application of thermal comfort of buildings. Differential scanning calorimetry is used to investigate the thermal properties of the prepared eutectic PCM and the result shows that the eutectic composition of 70% capric acid and 30% Cetyl Alcohol was suitable for low temperature thermal energy storage with melting and freezing temperature of 22.89 oC and 11.97 oC respectively. The latent heats of melting and freezing of the eutectic PCM are 144.92 J g-1 and 145.85 J g-1. The changes in melting point and latent heat of the eutectic mixtures over continuous charging/discharging cycles were presented. The accelerated thermal cycling test and Fourier transform infrared spectroscopy studies showed that the prepared eutectic PCM has good thermal stability over 1000 thermal cycles. Also, corrosion compatibility test for copper, aluminium and stainless steel 316 metal samples with the prepared eutectic PCM were also discussed and recommendations for using it in the operational environment were presented.
Vahide Nuran Mutlu - One of the best experts on this subject based on the ideXlab platform.
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esterification of Cetyl Alcohol with palmitic acid over wo3 zr sba 15 and zr sba 15 catalysts
Applied Catalysis A-general, 2016Co-Authors: Vahide Nuran Mutlu, Selahattin YilmazAbstract:Abstract Tungsten loaded and Zr incorporated SBA-15 catalysts (WO 3 /Zr-SBA-15 and Zr-SBA-15) were developed for esterification of Cetyl Alcohol and palmitic acid. The influence of the Zr content, tungsten loading amount, calcination temperature, feed composition and catalyst amount has been studied. Higher tungsten loading decreased the acidity due to formation of WO 3 crystals whereas calcination temperature enhanced the acidity by favoring the dispersion of WO x species. Activities of the catalyst changed depending on their amount of Bronsted sites and total number of acid sites. Zr-SBA-15 catalyst which had the highest amount of Bronsted acid sites gave maximum Cetyl palmitate yield (63.1%). This catalyst retained its activity up to 3 reuse cycles without significant loss of activity.
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Esterification of Cetyl Alcohol with palmitic acid over WO3/Zr-SBA-15 and Zr-SBA-15 catalysts
Applied Catalysis A: General, 2016Co-Authors: Vahide Nuran Mutlu, Selahattin YilmazAbstract:Abstract Tungsten loaded and Zr incorporated SBA-15 catalysts (WO 3 /Zr-SBA-15 and Zr-SBA-15) were developed for esterification of Cetyl Alcohol and palmitic acid. The influence of the Zr content, tungsten loading amount, calcination temperature, feed composition and catalyst amount has been studied. Higher tungsten loading decreased the acidity due to formation of WO 3 crystals whereas calcination temperature enhanced the acidity by favoring the dispersion of WO x species. Activities of the catalyst changed depending on their amount of Bronsted sites and total number of acid sites. Zr-SBA-15 catalyst which had the highest amount of Bronsted acid sites gave maximum Cetyl palmitate yield (63.1%). This catalyst retained its activity up to 3 reuse cycles without significant loss of activity.
Mamoru Senna - One of the best experts on this subject based on the ideXlab platform.
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an electron spin resonance study on the phase transition of the molecular assembly comprising Cetyltrimethylammonium chloride Cetyl Alcohol water
Langmuir, 2000Co-Authors: And Yoshifumi Yamagata, Mamoru SennaAbstract:The phase transition process of a molecular assembly comprising Cetyltrimethylammonium chloride (C16CA), Cetyl Alcohol (C16OH), and water was elucidated on the basis of electron spin resonance (ESR) spin probe method. ESR spectra for the ternary assembly incorporated with 5- and 16-doxylstearic acids (5-NS, 16-NS) showed definite anisotropic patterns, indicating restricted molecular motions in the bilayers. The order parameter, S33, and the hyperfine splitting constant AN‘ were higher in the 5-NS system than in the 16-NS. These findings suggest more marked restriction of molecular motions near the hydrophilic group in the bilayers and relatively free molecular motions toward the alkyl terminal. S33 and AN‘ for the 16-NS system were constant on aging, indicating invariance of the molecular motion and the degree of polarity near the terminal of alkyl group. A slight change of S33 for the 5-NS system was observed after aging for a few days. An empirical P parameter, a ratio of a fluid-like bilayer component ...
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An Electron Spin Resonance Study on the Phase Transition of the Molecular Assembly Comprising Cetyltrimethylammonium Chloride/Cetyl Alcohol/Water
Langmuir, 2000Co-Authors: And Yoshifumi Yamagata, Mamoru SennaAbstract:The phase transition process of a molecular assembly comprising Cetyltrimethylammonium chloride (C16CA), Cetyl Alcohol (C16OH), and water was elucidated on the basis of electron spin resonance (ESR) spin probe method. ESR spectra for the ternary assembly incorporated with 5- and 16-doxylstearic acids (5-NS, 16-NS) showed definite anisotropic patterns, indicating restricted molecular motions in the bilayers. The order parameter, S33, and the hyperfine splitting constant AN‘ were higher in the 5-NS system than in the 16-NS. These findings suggest more marked restriction of molecular motions near the hydrophilic group in the bilayers and relatively free molecular motions toward the alkyl terminal. S33 and AN‘ for the 16-NS system were constant on aging, indicating invariance of the molecular motion and the degree of polarity near the terminal of alkyl group. A slight change of S33 for the 5-NS system was observed after aging for a few days. An empirical P parameter, a ratio of a fluid-like bilayer component ...
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effects of temperature on the development of the internal structure of the Cetyltrimethylammonium chloride Cetyl Alcohol water system
Langmuir, 1999Co-Authors: Yoshifumi Yamagata, Mamoru SennaAbstract:Cetyltrimethylammonium chloride (C16CA) is added to a saturated solution containing an excess of aggregated spherical white solid globules of Cetyl Alcohol (C16OH) to give a semitranslucent gel (STG) spontaneously without stirring. Its internal structure was compared by morphology and thermal properties with a ternary mixture system (TMS) of the same composition but prepared by mixing and stirring at 75 °C. While dispersed particles in the TMS are multilamellar vesicles, the STG consists of anisotropic lamellae. The melting point is lower for lamellae than for vesicles because of the higher water content between lamellae. The interlamellar water content plays a critical role in the structural difference between the two assemblies.
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change in viscoelastic behaviors due to phase transition of the assembly comprising Cetyltrimethylammonium chloride Cetyl Alcohol water
Langmuir, 1999Co-Authors: Yoshifumi Yamagata, Mamoru SennaAbstract:The phase transition process of molecular assembly comprising Cetyltrimethylammonium chloride (C16CA), Cetyl Alcohol (C16OH), and water was analyzed on the basis of dynamic viscoelasticity, mainly by using Cole−Cole plots. The assembly prepared at 75 °C showed onionlike multilamellar vesicles (0.2−5 μm in diameter) immediately after preparation but transformed on aging into a rosary network of vesicles and finally fused into lamellae via polyhedra. The dynamic modulus (G‘) of the assembly monotonically increased with frequency, while the loss modulus (G‘ ‘) showed 2 peaks. The change in the angle parameters (αL, αS) calculated from Cole−Cole plots indicate the long and short time relaxation mechanisms, corresponding to the network of coagulated vesicles and lamellae, respectively.
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Change in Viscoelastic Behaviors Due to Phase Transition of the Assembly Comprising Cetyltrimethylammonium Chloride/Cetyl Alcohol/Water
Langmuir, 1999Co-Authors: Yoshifumi Yamagata, Mamoru SennaAbstract:The phase transition process of molecular assembly comprising Cetyltrimethylammonium chloride (C16CA), Cetyl Alcohol (C16OH), and water was analyzed on the basis of dynamic viscoelasticity, mainly by using Cole−Cole plots. The assembly prepared at 75 °C showed onionlike multilamellar vesicles (0.2−5 μm in diameter) immediately after preparation but transformed on aging into a rosary network of vesicles and finally fused into lamellae via polyhedra. The dynamic modulus (G‘) of the assembly monotonically increased with frequency, while the loss modulus (G‘ ‘) showed 2 peaks. The change in the angle parameters (αL, αS) calculated from Cole−Cole plots indicate the long and short time relaxation mechanisms, corresponding to the network of coagulated vesicles and lamellae, respectively.
Guiyin Fang - One of the best experts on this subject based on the ideXlab platform.
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microstructure and thermal properties of Cetyl Alcohol high density polyethylene composite phase change materials with carbon fiber as shape stabilized thermal storage materials
Applied Energy, 2017Co-Authors: Xiang Huang, Guruprasad Alva, Guiyin FangAbstract:This work presents an experiment on thermal properties of organic Cetyl Alcohol phase change materials (PCMs) incorporated with high density polyethylene (HDPE). Mass proportions of PCMs ranged from 70wt% to 90 wt%. Cetyl Alcohol (CtA) was chosen as the solid–liquid PCM and HDPE worked as the supporting material. While CtA performed as thermal energy storage medium, at the same time the leakage of the PCM was resolved by HDPE. The novel shape-stabilized composite phase change materials (CPCMs) were fabricated via impregnation of CtA into HDPE. In addition, the thermal conductivity of CPCMs was enhanced by carbon fiber (CF). The microstructure, crystalline phase and chemical structure were determined by scanning electronic microscope (SEM), X-ray diffractometer (XRD) and Fourier transformation infrared spectroscope (FT–IR). The results demonstrated that CtA was well impregnated into the HDPE. Differential scanning calorimeter (DSC) was utilized to analyze thermal properties of the composite phase change materials (CPCMs), the outcome indicated that the CPCMs nearly melted at around 50°C with a latent heat of 149.02–212.42kJ kg−1. Thermal gravimetric analyzer (TGA) confirmed that the CPCMs have an improved thermal reliability and the addition of CF contributed to a significant decrease in the leakage of CtA. The thermal conductivity meter (TCM) determined that the thermal conductivity of CPCM with 5wt% CF was 0.33W/(m K) and 0.47W/(m K) in liquid and solid state respectively, which was 1.25 and 1.22 times higher than that of original CPCM without CF. The experimental results indicate that the prepared CPCMs have prospects in thermal energy storage field.
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Microstructure and thermal properties of Cetyl Alcohol/high density polyethylene composite phase change materials with carbon fiber as shape-stabilized thermal storage materials
Applied Energy, 2017Co-Authors: Xiang Huang, Guruprasad Alva, Lingkun Liu, Guiyin FangAbstract:Abstract This work presents an experiment on thermal properties of organic Cetyl Alcohol phase change materials (PCMs) incorporated with high density polyethylene (HDPE). Mass proportions of PCMs ranged from 70 wt% to 90 wt%. Cetyl Alcohol (CtA) was chosen as the solid–liquid PCM and HDPE worked as the supporting material. While CtA performed as thermal energy storage medium, at the same time the leakage of the PCM was resolved by HDPE. The novel shape-stabilized composite phase change materials (CPCMs) were fabricated via impregnation of CtA into HDPE. In addition, the thermal conductivity of CPCMs was enhanced by carbon fiber (CF). The microstructure, crystalline phase and chemical structure were determined by scanning electronic microscope (SEM), X-ray diffractometer (XRD) and Fourier transformation infrared spectroscope (FT–IR). The results demonstrated that CtA was well impregnated into the HDPE. Differential scanning calorimeter (DSC) was utilized to analyze thermal properties of the composite phase change materials (CPCMs), the outcome indicated that the CPCMs nearly melted at around 50 °C with a latent heat of 149.02–212.42 kJ kg−1. Thermal gravimetric analyzer (TGA) confirmed that the CPCMs have an improved thermal reliability and the addition of CF contributed to a significant decrease in the leakage of CtA. The thermal conductivity meter (TCM) determined that the thermal conductivity of CPCM with 5 wt% CF was 0.33 W/(m K) and 0.47 W/(m K) in liquid and solid state respectively, which was 1.25 and 1.22 times higher than that of original CPCM without CF. The experimental results indicate that the prepared CPCMs have prospects in thermal energy storage field.