FOOD CHEMISTRY
·
2020
·
IF 6.306
Xi Zhou,Huiqin Wu,Xiaolan Huang,Fang Hang,Huitai Luo
This study established a simple and rapid method for determination of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) by dispersive liquid–liquid micro-extraction coupled with high performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q-TOF/MS) in white and red wines. Affecting variables, including extraction solvent, salt concentration, ultrasound-vortex conditions and ethanol content, were evaluated. Under optimized conditions, the limit of detection (LODs) for SCCPs and MCCPs were in the range of 0.15–3.00 ng mL −1 and 0.08–2.50 ng mL −1 , respectively. The spiked recoveries of SCCPs and MCCPs from white and red wine ranged from 63.2% to 127%. The method is precise with intra- and inter-day variations within 14.0% and 17.0%, respectively. SCCPs and MCCPs in wines from china varied widely, from
研究领域:
分析化学
·
食品安全
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2019
·
IF 2.813
Xi Zhou,Huiqin Wu,Xiaolan Huang,Fang Hang,Huitai Luo
This study established a simple and rapid method for simultaneous determination of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in human serum by high performance liquid chromatography coupled with electron spray ionization quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q-TOF/MS). A simple pretreatment procedure of protein precipitation by acetonitrile coupled with liquid-liquid extraction by n-hexane was employed for extraction and purification . The purified samples were separated by a PFP chromatographic column. This method could effectively eliminate the matrix effect by lipids and other matrix substances in serum samples with less time and solvent consuming. 76 congener groups of SCCPs and MCCPs with C 10 -C 17 and Cl 5 -Cl 13 were quantified by their [M-H] − ions. Method detection limit (MDL) were 1.0–8.0 ng mL −1 for ∑SCCPs and ∑MCCPs. Recoveries were 98.4 ± 4.42%, 98.8 ± 3.96% and 90.7 ± 2.79% for SCCPs and 93.1 ± 6.67%, 108 ± 1.21% and 90.8 ± 3.78% for MCCPs at spiking concentrations of 20, 50 and 200 ng·mL −1 , respectively. The relative standard deviations (RSDs) of intra- and inter-day variations were 1.41% and 9.84% for SCCPs, and 4.23% and 6.26% for MCCPs. The suitability of the developed method was demonstrated through the application to analysis of SCCPs and MCCPs in human serum samples.
研究领域:
环境科学
·
分析化学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Materials
·
2022
·
IF 3.985
Long Biyu,Zhou Xianzi,Cao Huafeng,Chen Renjie,He Nannan,Chi Lina,Fan Penghui,Chen Xiaohong
Superior encapsulation technology is important for PSCs to prolong their lifetime and realize their commercial application. Paraffin/EVA/paraffin composite encapsulated layers were fabricated with the ambient environment under the thermal temperature of 80°C, which has advantages for simple procedures and low cost. PSCs encapsulated with paraffin/EVA/paraffin and pure EVA layers maintained 95 and 45% of the initial power conversion efficiency (PCE) aged for 1000 h at RH 75%, respectively. Paraffin/EVA/paraffin-encapsulated PSCs were immersed in water for 5 h, which remained 98% of the original PCE, which is far superior to EVA-encapsulated PSCs. High melting point paraffin at 68°C shows better encapsulation than low melting point (60 and 55°C) paraffin, indicating that the high molecular weight of paraffin helps improve the encapsulation performance of PSCs. PSCs encapsulated with paraffin/EVA/paraffin showed better stability of Voc than pure EVA layer because paraffin can inhibit defects, voids, and edges of metal electrodes that quickly expand, and decay. Therefore, paraffin/EVA/paraffin combination encapsulation is an effective strategy, which can form continuous and dense hydrophobic composite encapsulation films with a friendly metal electrode.
研究领域:
材料科学
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
Gels
·
2023
·Vol. 9
·期 4
·317
·
IF 4.6
Linlin Xie,Xiaoxu Wu,Guichao Wang,Yury M. Shulga,Qiong Liu,Ming Li,Zhi Li
To address the leakage issue of paraffin phase-change materials in thermal management, a monolithic MTMS-based silica aerogel (MSA) is employed to encapsulate paraffin through a facile impregnation process. We find that the paraffin and MSA form a physical combination, with little interaction occurring between them. The prepared no-leakage paraffin/MSA composites have a density of 0.70 g/cm3and exhibit good mechanical properties and nice hydrophobicity, with a contact angle of 122°. Furthermore, the average latent heat of the paraffin/MSA composites is found to reach up to 209.3 J/g, about 85% of the pure paraffin’s latent heat, which is significantly larger than other paraffin/silica aerogel phase-change composite materials. The thermal conductivity of the paraffin/MSA remains almost the same as that of the pure paraffin (~250 mW/m/K), without any heat transfer interference from the MSA skeletons. All these results indicate that MSA can effectively serve as a carrier material for encapsulating paraffin, which is beneficial for expanding the applications of MSAs in thermal management and energy storage.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2013
·
IF 2.775
Keping Chen,Xuejiang Yu,Chunrong Tian,Jianhua Wang
Polyurethane phase change material (PUPCM) has been demonstrated to be effective solid–solid phase change material for thermal energy storage. However, the high cost and complex process on preparation of PUPCMs with high enthalpy and broad phase transition temperature range can prohibit industrial-scale applications. In this work, a series of novel form-stable paraffin/PUPCMs composites ( n -octadecane/PUPCM, n -eicosane/PUPCM and paraffin wax/PUPCM) with high enthalpy and broad phase transition temperature range (20–65 °C) were directly synthesized via bulk polymerization. The composites were prepared at different mass fractions of n -octadecane (10, 20, 25, 30% w/w). The results indicated that the maximum encapsulation ratio for n -octadecane/PUPCM10000 composites was around 25% w/w. The chemical structure and crystalline properties of these composites were characterized by Fourier transform infrared spectroscopy (FT-IR), polarizing optical microscopy (POM), wide-angle X-ray diffraction (WAXD). Thermal properties and thermal reliability of the composites were determined using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). From DSC analysis, the composites showed a typical dual phase change temperature. The enthalpy for the composite with 25% w/w n -eicosane was as high as 141.2 J/g. TGA analysis indicated that the composites degraded at considerably high temperatures. The process of preparation of PUPCMs and their composites was very simple, inexpensive, environmental friendly and easy to process into desired shapes, which could find the promising applications in solar energy storage and building.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 18
·9962-9967
·
IF 3.049
Yiwen Hu,Xiuduo Song,Qilong Zheng,Jiangning Wang,Jiangfei Pei
Zeolitic imidazolate framework-67 (ZIF-67), a new kind of metal–organic framework, has large surface area as well as outstanding thermal and chemical stability. In this paper, micro-sized ZIF-67 crystals were prepared and further employed as the reinforcing material to design novel paraffin-based composite phase change materials (PCMs) with a polymethyl methacrylate (PMMA) shell. The composite PCMs were fabricated by using a ZIF-67 crystal-stabilized oil-in-water (O/W) Pickering emulsion as a template. Morphologies and thermal properties of the prepared composite PCMs with different contents of ZIF-67 crystals were determined by SEM, DSC and TGA. Results showed that the ZIF-67 concentration in the emulsion system has a significant effect on the microstructure, phase change behavior and thermal stability of the resultant composite PCMs. When adding 1.5 g of ZIF-67 crystals, the resultant composite PCMs achieved a stable sphere-like structure and had about 106.06 J g−1 of latent heat. The prepared composite PCMs also exhibited a good thermal stability. Compared with pure paraffin, the thermostability of the shape-stabilized paraffin was significantly enhanced at a low content of ZIF-67 crystals.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Qingsong Lian,Yan Li,Asim A. S. Sayyed,Jue Cheng,Junying Zhang
Designing novel phase change materials (PCMs) is of vital importance in achieving the sustainable development of energy. Here, we facilely prepare a series of novel multiple solid–solid PCMs (SSPCMs, EPPa-X systems) by blending paraffin, epoxy resin with crystalline side chains (D18), and poly(propylene oxide)diamine together followed by a one-pot curing process. Strong intermolecular forces between paraffin and D18 (based on their good compatibility) and a reliable three-dimensional (3-D) cross-linking network of epoxy resin form a unique encapsulation mechanism, which provides the EPPa-X SSPCMs with excellent shape-stable properties and superior thermal stability (remain stable below 180 °C) without sacrificing too much latent heat of paraffin (only 1.6% latent heat loss). Due to the combination of two melting processes at 36 and 60 °C derived from D18 and paraffin, respectively, the latent heat of the EPPa-50 system is high, up to 152.6 J/g. Besides, the supercooling extent of D18 decreased from 13.6 to 10.5 °C with the addition of paraffin due to the heterogeneous nucleation effect. The novel EPPa-X SSPCMs possess tremendous potential for a wide range of applications due to their facile preparation, low cost, high reliability, and excellent phase change properties, while the unique encapsulation mechanism may open a new door for preparing other novel types of PCMs.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Xuanyan Liu,Shuo Wang,Jiaxing Wang,Hongdi Fu,Kangcheng Xu,Xiaodong Li,Tinglu Song,Meishuai Zou
Aluminum-lithium alloys (Al-Li alloys) have gained prominence in recent years as promising alternatives to aluminum powders, attributed to their superior thermal and combustion characteristics. However, the high reactivity of Al-Li alloys poses significant challenges to their stability and compatibility with other materials. This study utilized high-energy ball milling to modify Al-Li alloys by incorporating polytetrafluoroethylene (PTFE) and paraffin wax (WAX) as functional coatings. Thermal analysis of Al-Li/PTFE composites revealed a marked reduction in the thermal oxidative exothermic peak temperature with the addition of 10 % and 15 % PTFE, accompanied by enthalpy increases of 1.49 and 2.1 times, respectively. Combustion processes captured using a high-speed camera demonstrated that increasing the PTFE content from 10 % to 30 % intensified the combustion and reduced combustion duration by 50 %. The agglomeration of combustion residues also decreased. Furthermore, incorporating WAX through ball milling facilitated high-temperature phase transformations, producing Al-Li/10PTFE/2WAX composite powders with enhanced antioxidant properties, as evidenced by a contact angle of 131.15°, and improved compatibility. The findings offer a pathway for achieving tunable combustion performance in Al-Li alloys while addressing critical issues related to the storage and processing of these powders for practical applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2023
·Vol. 30
·期 4
·1-13
·
IF 2.8
Du Qingyuan,Li Chenglin,Sun Jingyao,Zhang Hao,Zhang Xiaowen,Liu Changhao,Wu Daming,He Jianyun,Guo Zhanhu
Phase change materials (PCMs) have been widely used in passive thermal management and energy storage due to their high latent heat capacity. However, the low thermal conductivity and leakage problems of PCMs are two bottlenecks for its application in the field of heat-related applications. Although many present studies can tackle one or two of these problems by preparing phase change composites (PCCs), it is still a challenge to achieve high performance PCCs with excellent thermal, mechanical, and phase change properties simultaneously. In this work, we report a spatial confining forced network assembly (SCFNA) method to efficiently prepare the thermal conductive, flexible, leak-proof hexagonal boron nitride/paraffin wax/ polydimethylsiloxane (hBN/PW/PDMS) PCCs by constructing hBN and PW thermal conductive networks as the functional matrix of PCCs. In the hBN/PW/PDMS PCCs, PW is served as the PCM, a dense hBN network provides the high thermal conductivity, and the mechanical properties and shape stability are provided by PDMS. The hBN/PW/PDMS PCCs as thermal interface materials reduce the LED chips surface temperature and exhibit efficient and reliable thermal management performance. Our work provides an efficient and economical method for the preparation of PCCs with outstanding thermal management capability.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 42
·
IF 1.866
Yu Zhang,Jia Song,Hongling Chen
The purpose of the present work was to develop a fragrance encapsulation system using polyacrylate/paraffin microcapsules. The Polyacrylate/paraffin microcapsules were fabricated by the method of suspension polymerization in Pickering emulsion. Morphology, size distribution, and thermal resistance of polyacrylate/paraffin microcapsules were investigated by scanning electron microscopy, light scattering particle size analyzer, and thermogravimetric analyzer. Results indicated that the crosslinked PMMA/paraffin microcapsules and P(MMA-co-BMA)/paraffin microcapsules prepared under optimal conditions presented regular spherical shape and similar size distribution. The crosslinked P(MMA-co-BMA)/paraffin microcapsules exhibited better thermal stability, with a thermal resistance temperature up to 184 °C. Fragrance microcapsules were prepared by encapsulating fragrance into crosslinked P(MMA-co-BMA)/paraffin microcapsules. The prolonged release performance of fragrance microcapsules was measured by ultraviolet-visible near-infrared spectrophotometer. 63.9% fragrance was retained after exposing fragrance microcapsules in air for 3 months, and the fragrance continued to release over 96 h in surfactant solution (sodium lauryl sulfonate, 20 wt %). © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 44136.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2025
·
IF 2.8
Jianjun Zhou,Xing Liu,Jianqing Zhao
The preparation of phase change materials (PCMs) with excellent heat storage capacity, shape stability, and working durability is of vital importance for their popularization and application. In this work, a series of form-stable PCMs was prepared via blending diglycidyl ether of bisphenol A (DGEBA), aliphatic anhydride with octadecyl side chains (MNAO), and paraffin together followed by thermal curing. Thanks to the plasticizing effect and self-assembly of paraffin, the crystalline behavior of paraffin and MNAO was hardly limited by the epoxy network, and the latent heat of EP/Pa-50 with 50 wt% paraffin content was high, up to 92.3 J/g. Meanwhile, EP/Pa-50 had a low supercooling extent of 11.0°C. Instead of the significant reduction in other properties of most PCMs after being blended with paraffin, the overall performance of EP/Pa-50 remained good due to the strong intermolecular interactions between paraffin and MNAO (based on their good compatibility) and the reliable epoxy network, and EP/Pa-50 exhibited excellent shape stability without the leakage problem, high thermal stability (remain stable below 170°C) and good mechanical properties (tensile strength up to 10.5 MPa). This work provides a facile strategy to prepare form-stable PCMs, which have promising application prospects in the field of thermal regulation.
研究领域:
材料科学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
PETROLEUM CHEMISTRY
·
2024
·Vol. 64
·期 2
·297-308
·
IF 1.3
Han Yating,Xia Xia,Peng Zexuan,Xiao Yang
Abstract To address the limitations of the existing catalytic hydrogenation and sulfuric acid sulfonation intended to remove aromatic hydrocarbons from liquid paraffin oils, the adsorption method was chosen for the adsorptive separation of phenanthrene, a typical aromatic hydrocarbon, from liquid paraffin oils. A zeolite imidazolate framework-8 (ZIF-8) precursor was firstly prepared, and then ZIF-8-derived porous carbon (ZDPC) adsorbents were obtained using different temperatures of carbonization of the precursor under nitrogen atmosphere; these adsorbents were then used for the adsorption and separation of phenanthrene from liquid paraffin oils. The experiment showed that the maximum specific surface area of a ZDPC adsorbent could reach 1458 m 2 /g at 900°C. However, the total pore volume and adsorption capacity of ZDPC porous carbon were maximal at the carbonization temperature of 800°C (1.59 cm 3 /g and 931 mg/g, respectively). The obtained results showed that an increase in the specific surface area of the adsorbent did not necessarily enhance the adsorption performance. However, compared with the specific surface area of the adsorbent, its adsorption performance is improved in the case of larger pore structures. Therefore, the pore structure of the adsorbent has a very important influence on the adsorption performance. The results of kinetic and thermodynamic studies showed that the pseudo-second-order model could better explain the adsorption process of ZDPC on phenanthrene, while the intra-particle diffusion model revealed that the adsorption mechanism represented a continuous three-stage process.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）