Synthesis of n-octadecane/poly (styrene-methyl methacrylate) (St-MMA) energy-storage microcapsules via emulsion polymerization

2017 ◽  
Vol 31 (11) ◽  
pp. 1443-1454
Author(s):  
Weili Wu ◽  
Zhe Chen
Keyword(s):  
Particle Size ◽  
Energy Storage ◽  
Methyl Methacrylate ◽  
Phase Change ◽  
Emulsion Polymerization ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Size Dispersion

Poly (methyl methacrylate) block copolymer is interesting due to its good compatibility with many polymers. In this study, a novel phase-change energy storage material, n-octadecane/poly (styrene-methyl methacrylate) (OD/P(St-MMA)) microcapsules, were designed and synthesized by emulsion polymerization, in which n-OD was used as core materials, the copolymer of St and MMA as shell materials, and sodium dodecyl benzene sulfonate (SDBS) as emulsifier. The morphology, phase-change thermal properties and thermal stability of microcapsules were investigated by particle size analyzer, transmission electron microscope, thermogravimetric (TG) analyzer, and differential scanning calorimetry (DSC). The results showed that when the ratio of the two monomers, St and MMA, was 1/5 and the dosage of SDBS was 1.5 g (3% of the total mass), the particle size dispersion of microcapsules was uniform and microcapsule particles were well wrapped. TG analysis showed that the long-term use temperature of microcapsules could not exceed 131°C. DSC showed that the phase-change enthalpy of microcapsule was 148.39 J·g−1, which indicated the microcapsules had excellent energy storage property.

SYNTHESIS AND CHARACTERIZATION OF POLY(BUTYL ACRYLATE-CO-METHYL METHACRYLATE)/CLAY NANOCOMPOSITES VIA EMULSION POLYMERIZATION

2006 ◽  
Vol 05 (02n03) ◽  
pp. 291-297 ◽  
Author(s):  
ZHIYI ZHANG ◽  
NING ZHAO ◽  
WEI WEI ◽  
DONG WU ◽  
YUHAN SUN
Keyword(s):  
Methyl Methacrylate ◽  
Emulsion Polymerization ◽  
Butyl Acrylate ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Clay Nanocomposites ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Dodecyl Benzene Sulfonate ◽  
Clay Layers

Poly(butyl acrylate-co-methyl methacrylate)/clay nanocomposites were synthesized via emulsion polymerization with an emulsifier (sodium dodecyl benzene sulfonate, SDBS), an initiator (ammonium persulate, APS), acrylic acid ester monomer and Na -montmorillonite. It was found that the addition of SDBS and water widened the gap between clay layers and facilitated monomers to penetrate into clay. Through initiator, comonomers were polymerized in the montmorillonite galleries. The structure of extracted nanocomposites was confirmed by XRD, transmission electron microscopy (TEM). Their thermal property and molecule weight were investigated by differential scanning calorimetry (DSC) and gel-penetrate chromatogram (GPC).

scholarly journals Demonstration of Phase Change Thermal Energy Storage in Zinc Oxide Microencapsulated Sodium Nitrate

2021 ◽  
Vol 11 (13) ◽  
pp. 6234
Author(s):  
Ciprian Neagoe ◽  
Ioan Albert Tudor ◽  
Cristina Florentina Ciobota ◽  
Cristian Bogdanescu ◽  
Paul Stanciu ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Thermal Properties ◽  
High Temperature ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Sodium Nitrate ◽  
Thermal Energy Storage ◽  
Metal Corrosion ◽  
Scanning Calorimetry

Microencapsulation of sodium nitrate (NaNO3) as phase change material for high temperature thermal energy storage aims to reduce costs related to metal corrosion in storage tanks. The goal of this work was to test in a prototype thermal energy storage tank (16.7 L internal volume) the thermal properties of NaNO3 microencapsulated in zinc oxide shells, and estimate the potential of NaNO3–ZnO microcapsules for thermal storage applications. A fast and scalable microencapsulation procedure was developed, a flow calorimetry method was adapted, and a template document created to perform tank thermal transfer simulation by the finite element method (FEM) was set in Microsoft Excel. Differential scanning calorimetry (DSC) and transient plane source (TPS) methods were used to measure, in small samples, the temperature dependency of melting/solidification heat, specific heat, and thermal conductivity of the NaNO3–ZnO microcapsules. Scanning electron microscopy (SEM) and chemical analysis demonstrated the stability of microcapsules over multiple tank charge–discharge cycles. The energy stored as latent heat is available for a temperature interval from 303 to 285 °C, corresponding to onset–offset for NaNO3 solidification. Charge–self-discharge experiments on the pilot tank showed that the amount of thermal energy stored in this interval largely corresponds to the NaNO3 content of the microcapsules; the high temperature energy density of microcapsules is estimated in the range from 145 to 179 MJ/m3. Comparison between real tank experiments and FEM simulations demonstrated that DSC and TPS laboratory measurements on microcapsule thermal properties may reliably be used to design applications for thermal energy storage.

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.

scholarly journals The Evaluation of Meloxicam Nanocrystals by Oral Administration with Different Particle Sizes

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 421
Author(s):  
Yao Yu ◽  
Yang Tian ◽  
Hui Zhang ◽  
Qingxian Jia ◽  
Xuejun Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Water Solubility ◽  
Cell Model ◽  
Particle Sizes ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Laser Scattering ◽  
Transport Studies ◽  
Transmission Electron ◽  
Transmission And Absorption

Meloxicam (MLX) is a non-steroidal anti-inflammatory drug used to treat rheumatoid arthritis and osteoarthritis. However, its poor water solubility limits the dissolution process and influences absorption. In order to solve this problem and improve its bioavailability, we prepared it in nanocrystals with three different particle sizes to improve solubility and compare the differences between various particle sizes. The nanocrystal particle sizes were studied through dynamic light scattering (DLS) and laser scattering (LS). Transmission electron microscopy (TEM) was used to characterize the morphology of nanocrystals. The sizes of meloxicam-nanocrystals-A (MLX-NCs-A), meloxicam-nanocrystals-B (MLX-NCs-B), and meloxicam-nanocrystals-C (MLX-NCs-C) were 3.262 ± 0.016 μm, 460.2 ± 9.5 nm, and 204.9 ± 2.8 nm, respectively. Molecular simulation was used to explore the distribution and interaction energy of MLX molecules and stabilizer molecules in water. The results of differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD) proved that the crystalline state did not change in the preparation process. Transport studies of the Caco-2 cell model indicated that the cumulative degree of transport would increase as the particle size decreased. Additionally, plasma concentration–time curves showed that the AUC0–∞ of MLX-NCs-C were 3.58- and 2.92-fold greater than those of MLX-NCs-A and MLX-NCs-B, respectively. These results indicate that preparing MLX in nanocrystals can effectively improve the bioavailability, and the particle size of nanocrystals is an important factor in transmission and absorption.

scholarly journals Thermal Storage of Nitrate Salts as Phase Change Materials (PCMs)

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7223
Author(s):  
Marco A. Orozco ◽  
Karen Acurio ◽  
Francis Vásquez-Aza ◽  
Javier Martínez-Gómez ◽  
Andres Chico-Proano
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Sodium Nitrite ◽  
Phase Change Materials ◽  
Storage Capacity ◽  
Thermal Storage ◽  
Potassium Nitrate ◽  
Ternary Mixtures ◽  
Scanning Calorimetry ◽  
Nitrate Salts

This study presents the energy storage potential of nitrate salts for specific applications in energy systems that use renewable resources. For this, the thermal, chemical, and morphological characterization of 11 samples of nitrate salts as phase change materials (PCM) was conducted. Specifically, sodium nitrate (NaNO3), sodium nitrite (NaNO2), and potassium nitrate (KNO3) were considered as base materials; and various binary and ternary mixtures were evaluated. For the evaluation of the materials, differential Fourier transform infrared spectroscopy (FTIR), scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) to identify the temperature and enthalpy of phase change, thermal stability, microstructure, and the identification of functional groups were applied. Among the relevant results, sodium nitrite presented the highest phase change enthalpy of 220.7 J/g, and the mixture of 50% NaNO3 and 50% NaNO2 presented an enthalpy of 185.6 J/g with a phase change start and end temperature of 228.4 and 238.6 °C, respectively. This result indicates that sodium nitrite mixtures allow the thermal storage capacity of PCMs to increase. In conclusion, these materials are suitable for medium and high-temperature thermal energy storage systems due to their thermal and chemical stability, and high thermal storage capacity.

Preparation and properties of shape-stabilized phase change material cellulose benzoate-g-polyoxyethylene (2) hexadecyl ether with potential for thermal energy storage

2018 ◽  
Vol 89 (8) ◽  
pp. 1512-1521
Author(s):  
Na Han ◽  
Wenxin Zhang ◽  
Xiufang Wang ◽  
Xingxiang Zhang ◽  
Wei Li ◽  
...  
Keyword(s):  
Phase Transition ◽  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solid Phase ◽  
Resonance Spectroscopy ◽  
Thermal Reliability ◽  
Scanning Calorimetry ◽  
Chemical Structures

It is a worldwide challenge to efficiently use renewable resources to solve the current energy shortage. The existing cellulose-based material is incapable of proper power storage. In this study, a series of cellulose benzoate-g-polyoxyethylene (2) hexadecyl ether (CB-g-E2C16) solid–solid phase change materials were synthesized with cellulose as the skeleton and polyoxyethylene (2) hexadecyl ether (E2C16) as a functional side chain. The skeleton cellulose and benzoyl chloride restrict the free movement of the molecular chains of E2C16 above the phase transition temperature, leading to a solid–solid phase change. Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy were performed to investigate the chemical structures. The thermal energy-storage properties, thermal reliability and thermal stability of the CB-g-E2C16 were investigated by differential scanning calorimetry and thermogravimetry (TG) methods. The analysis results indicated that the E2C16 chains were successfully grafted onto the cellulose benzoate (CB) backbone and the copolymers exhibited typical solid–solid phase transition behavior. The enthalpy and degree of substitution of graft copolymers CB-g-E2C16 could be adjusted by changing the feeding ratio of the raw materials, reaction temperature and post-processing methods of CB. TG analysis results showed that the CB-g-E2C16 copolymers possessed good thermostability and they keep their stability up to 278℃. Compared with pure cellulose, CB-g-E2C16 copolymers could be dissolved in dimethyl sulfoxide and most of them could be dissolved in N, N-dimethylformamide.

Preparation and characterization of phase-change energy storage nonwoven fabric

2021 ◽  
pp. 152808372110417
Author(s):  
Zhou Zhao ◽  
Ningning Tong ◽  
Hong Song ◽  
Yan Guo ◽  
Jinmei Wang
Keyword(s):  
Phase Transition ◽  
Thermal Stability ◽  
Energy Storage ◽  
Phase Change ◽  
Nonwoven Fabric ◽  
Scanning Calorimetry ◽  
Change Material ◽  
Stretching Process ◽  
Thermal Stability Of

In this work, a phase-change energy storage nonwoven fabric was made of polyurethane phase-change material (PUPCM) by a non-woven melt-blown machine. Polyethylene glycol 2000 was used as the phase transition unit and diphenyl-methane-diisocyanate as the hard segment to prepare PUPCM. Thermal stability of the PUPCM was evaluated through thermal stability analysis. The performance of pristine PUPCM was determined by Fourier transform infrared spectroscopy and differential scanning calorimetry to analyze the spinning technology of spinning temperature and the stretching process. Phase-change energy storage nonwoven fabric (413.22 g/m2) was prepared, and the morphology, solid–solid exothermic phase transition, mechanical properties, and the structures were characterized. The enthalpy of solid–solid exothermic phase transition reached 60.17 mJ/mg (peaked at 23.14°C). The enthalpy of solid–solid endothermic phase transition reached 67.09 mJ/mg (peaked at 34.34°C). The strength and elongation of phase-change energy storage nonwoven fabric were found suitable for garments and tent fabrics.

scholarly journals A Comparative Study of the Effect of Different Stabilizers on the Critical Quality Attributes of Self-Assembling Nano Co-Crystals

Pharmaceutics ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 182 ◽  
Author(s):  
Bwalya A. Witika ◽  
Vincent J. Smith ◽  
Roderick B. Walker
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Antiviral Agents ◽  
Sodium Dodecyl ◽  
Quality Attributes ◽  
Polydispersity Index ◽  
Scanning Calorimetry ◽  
Critical Quality Attributes ◽  
X Ray ◽  
Self Assembling

Lamivudine (3TC) and zidovudine (AZT) are antiviral agents used orally to manage HIV/AIDS infection. A pseudo one-solvent bottom-up approach was used to develop and produce nano co-crystals of 3TC and AZT. Equimolar amounts of 3TC dissolved in de-ionized water and AZT in methanol were rapidly injected into a pre-cooled vessel and sonicated at 4 °C. The resultant suspensions were characterized using a Zetasizer. The particle size, polydispersity index and Zeta potential were elucidated. Further characterization was undertaken using powder X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and energy dispersive X-ray spectroscopy scanning electron microscopy. Different surfactants were assessed for their ability to stabilize the nano co-crystals and for their ability to produce nano co-crystals with specific and desirable critical quality attributes (CQA) including particle size (PS) < 1000 nm, polydispersity index (PDI) < 0.500 and Zeta potential (ZP) < −30 mV. All surfactants produced co-crystals in the nanometer range. The PDI and PS are concentration-dependent for all nano co-crystals manufactured while only ZP was within specification when sodium dodecyl sulfate was used in the process.

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