COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Haibo Ding,Haopeng Zhang,Qinshan Xie,Ali Rahman,Yanjun Qiu
Wax crystals may continuously precipitate from the asphalt binder during the cooling process, which seriously damages the low-temperature cracking resistance of the pavement. At present, few researchers have developed wax inhibitors (WIs) to hinder wax crystallization of the asphalt binders. In this paper, a novel wax Inhibitor was synthesized by the hybridization of organically modified Nano-SiO 2 to the poly (methyl methacrylate) (PMMA), and the modification effect was validated by the ninhydrin chromogenic method and thermogravimetric analysis . The optimum content and composition of the organic nano-SiO 2 hybrid PMMA WIs were also determined by the rheological tests, including viscosity measurement , wax precipitation temperature (WPT), and yield stress tests. Moreover, the wax inhibition mechanism was predicted by the combination of differential scanning calorimetry (DSC) and polarized optical microscopy (POM) tests. According to the obtained results, the successful modification of nano-SiO 2 and PMMA were represented by the blue-violet precipitation and improved high temperature stability of PMMA, respectively. The optimal content and composition of nano-SiO 2 hybrid PMMA was determined as 200 ppm and mass ratio of 1:4 (nano-SiO 2 to PMMA), respectively. Compared with the co-crystallization between PMMA and wax crystals, the introduction of nano-SiO 2 provided an additional and more stable heterogeneous nucleation template, which further reduced the size, and increased the dispersion of the wax crystals. Consequently, it is promising to develop the nanocomposites as WIs in the asphalt binder.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
Nanomaterials
·
2023
·Vol. 13
·期 6
·1085
·
IF 5.3
Qingchao Zhou,Zhongyi Shang
The commercial application of colloidal semiconductor nanocrystals has been realized owing to the development of composite film technology. Here, we demonstrated the fabrication of green and red emissive CuInS2nanocrystals embedded polymer composite films of equal thickness by using a precise solution casting method. The impacts of polymer molecular weight on the dispersibility of CuInS2nanocrystals were then systematically studied through evaluating the decrease in transmittance and red shift of emission wavelength. The composite films made from PMMA of small molecular weights exhibited higher transmittance. Applications of these green and red emissive composite films as color converters in remote-type light-emitting devices were further demonstrated.Keywords:CuInS2nanocrystals;PMMA;composite films;molecule weights;white LEDs
研究领域:
材料科学
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光学工程
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Meina Xu,Qi Cheng,Ligang Lin,Jing Yang,Zitian Liu,Xu Yang,Qiying Wang,Fengling Tang,Aishan He,Chunhong Wang,Xiaolan Zhang
Films and surfaces with controlled patterns and features have attracted significant attention due to their widespread engineering applications. In this study, a new strategy based on phase separation-induced surface segregation is proposed. Different molecular chains in a polymer solution moved in different directions. During the segregation process, the molecular chains entangled with each other, hindering each other's migratory behavior, thus forming patterned structure on the surface of the film. Thin films with patterned surface topography were prepared by this method. The results indicate that the surface segregation phenomenon occurs during the film preparation. The surface structure of the films was influenced by the polymer ratio, solution concentration, thickness of the cast film and the solvent volatility. The fabricated films depict ordered topography, containing features with an average diameter of 2.23 μm when the polystyrene/poly(methyl methacrylate) ratio of 6:1, solution concentration of 10%, evaporation temperature of 30 °C, and a cast thickness of 0.1 mm were used. Therefore, based on simple blending combined with surface segregation strategy while optimizing the experimental conditions, patterned films with controlled topology were fabricated with preferred hydrophilic or hydrophobic characteristics. These observations are encouraging for the development of smart engineered surfaces with functional characteristics.
研究领域:
材料科学
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表面工程
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产品关联
DOI
高影响因子
Journal of Energy Storage
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2022
·
IF 8.907
Jun Li,Haoxin Chen,Lisi Jia,Xiaoyun Zhu,Guangjun Qin,Ying Chen
Hydrated salts have been considered as a promising phase change material for usage in low-temperature thermal energy storage applications ; however, they suffer from poor thermal reliability, corrosiveness, and inefficient thermal storage. Nanoencapsulation is an effective approach used to improve the thermal energy storage performance and reliability of phase change materials. At present, limited studies have been conducted on the core–shell encapsulation-based hydrated salt core. In this work, an efficient method was developed for the encapsulation of Na 2 HPO 4 ·12H 2 O into the polymethylmethacrylate (PMMA) nanocapsules . The morphology and core–shell structure of the nanocapsules were investigated using scanning electron microscope (SEM) and transmission electron microscope (TEM). The chemical composition of the nanocapsules was confirmed by Fourier transformation infrared spectroscopy (FTIR). The phase change performance of the nanocapsules was studied using a differential scanning calorimeter (DSC). Thermal cycling was adopted to reveal the thermal reliability of the nanocapsules. The corrosiveness of the nanocapsules was also investigated. In addition, the nanocapsules were combined with copper foam to prepare a novel composite phase change material (C-PCM) for efficient thermal energy storage. Results demonstrated that the melting and solidifying latent heat of the nanocapsules were 157.3 and 140.6 kJ/kg, respectively. The encapsulation ratio of the nanocapsules was 64.1 %, and 97.7 % was maintained after 500 thermal cycles. Hydrated salt nanocapsules were virtually non-corrosive to the metal. The latent heat of the composite PCM was calculated to be approximately 72.7 kJ/kg. The thermal conductivity of the composite PCM was about 1.25 W/(m·K), 5.5 times higher than that of the nanocapsules. The heat storage test showed that the time required for the heat storage of the C-PCM was reduced by about 82.8 % compared with that of the pure nanocapsules. This novel nanocapsule has high phase change properties and thermal reliability and exhibits good low-temperature thermal energy storage prospects.
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
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2024
·Vol. 62
·期 15
·3460-3470
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IF 3.9
Yuxuan Zhu,Zhicheng Liu,Ziran Liu,Danfeng Zhou,Guoqiang Luo,Jiuxiao Sun,Peng Cao,Qiang Shen
Microcellular composites combine the advantages of composite material and microcellular material. Introducing the inclusion phase into the polymer matrix can optimize the cellular structure and improve the mechanical properties of microcellular materials. This paper focuses on rigid W particles reinforced PMMA microcellular materials, combining compression experiments and meso FE simulations to investigate the structure–property relationship of cellular structure and compressive properties for W/PMMA microcellular composites. The results indicate that W particles promote heterogeneous nucleation, reducing the cell size to 3 μm, and reinforce the PMMA matrix. W particles (10 → 60 wt%) are linearly and exponentially related to compressive modulus and compressive strength of W/PMMA microcellular composites, increased by 49.3% and 19.8%. Void porosity (71% → 48%) is quadratic related to compressive properties of W/PMMA microcellular composites, increased by 109%. Cell sizes (5 → 1 μm, especially smaller than the W particle sizes) are exponentially related to compressive properties of W/PMMA microcellular composites, increased by 38.5%. This work provides theoretical support for the regulation of cellular structure and optimization of mechanical properties of microcellular materials. Graphical
研究领域:
材料科学
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力学工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL POLYMER PROCESSING
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2024
·
IF 1.1
Huimin Xue,Chun Li,Jiayang Sui,Lifei Liu,Xiaokun Ma,Chenhong Liang,Weizhen Zhao
Wind turbine (WT) blade fabrication typically employs thermosetting resins, whose recycling challenges post-retirement have resulted in environmental pressures. Thus, there is an urgent need to develop a low-viscosity, high-performance, and recyclable material with excellent mechanical properties that is compatible with WT fabrication processes, serving as a viable alternative to traditional epoxy resins. Poly(methyl methacrylate) (PMMA) resin is considered a promising candidate for replacing epoxy resins. However, the mechanical properties of PMMA still require improvement. In this study, we investigated the effects of introducing copolymerized monomers on the comprehensive performance of PMMA resin without affecting its viscosity, examining the influence of these copolymerized monomers on the material’s thermal and mechanical properties. Meanwhile, the mechanical properties of the synthesized PMMA-based copolymers were compared with those of blade-specific epoxy resin (WD0135). The results revealed that compared to WD0135, the flexural strength and modulus of the prepared PMMA copolymers significantly increased to 96.6 and 3158.6 MPa, respectively, with a tensile strength reaching 74.2 MPa. Consequently, this series of PMMA-based resins demonstrates immense potential for large-scale material part fabrication via casting techniques.
研究领域:
材料科学
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可再生能源工程
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 7
·1570
·
IF 3.1
Luchao Yan,Yang Wang,Shijian Lu,Zhipeng Zhu,Lingling Xu
With the fast development of the cold chain transportation industry, the traditional refrigeration method results in significant energy consumption. To address the national call for energy saving and emission reduction, the search for a new type of energy storage material has already become a future development trend. According to the national standard GB/T28577 for the classification and basic requirements of cold chain logistics, the temperature in frozen logistics is typically below −18 °C. In this study, n-undecane with a phase change temperature of −26 °C is chosen as the core material of microcapsules. Poly(methyl methacrylate) is applied as the shell material, with n-undecane microcapsules being prepared through suspension polymerization for phase change cold storage materials (MEPCM). Using characterization techniques including SEM, DSC, FTIR, and laser particle size analysis, the effects of three types of emulsifiers (SMA, Tween-80, Tween-80/span-80 (70/30)), SMA emulsifier dosage, core–shell ratio, and emulsification rate on the thermal performance and micro-surface morphology of n-undecane/PMMA microcapsules were studied. The results indicate that when comparing SMA, Tween-80, and Tween-80/span-80 (70/30) as emulsifiers, the dodecane/PMMA microcapsules prepared with SMA emulsifier exhibit superior thermal performance and micro-surface morphology, possessing a complete core–shell structure. The optimal microstructure and the highest enthalpy of phase change, measuring 120.3 kJ/kg, are achieved when SMA is used as the emulsifier with a quantity of 7%, a core-to-wall ratio of 2.5:1, and an emulsification speed of 2000 rpm. After 200 hot and cold cycles, the enthalpy of phase change decreased by only 18.6 kJ/kg, indicating the MEPCM thermal performance and cycle life. In addition, these optimized microcapsules exhibit favorable microstructure, uniform particle size, and efficient energy storage, making them an excellent choice for the refrigeration and freezing sectors.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Biosensors-Basel
·
2021
·Vol. 11
·期 5
·162
·
IF 5.519
Mathias Busek,Steffen Nøvik,Aleksandra Aizenshtadt,Mikel Amirola-Martinez,Thomas Combriat,Stefan Grünzner,Stefan Krauss
Polydimethylsiloxane (PDMS) has been used in microfluidic systems for years, as it can be easily structured and its flexibility makes it easy to integrate actuators including pneumatic pumps. In addition, the good optical properties of the material are well suited for analytical systems. In addition to its positive aspects, PDMS is well known to adsorb small molecules, which limits its usability when it comes to drug testing, e.g., in organ-on-a-chip (OoC) systems. Therefore, alternatives to PDMS are in high demand. In this study, we use thermoplastic elastomer (TPE) films thermally bonded to laser-cut poly(methyl methacrylate) (PMMA) sheets to build up multilayered microfluidic devices with integrated pneumatic micro-pumps. We present a low-cost manufacturing technology based on a conventional CO2laser cutter for structuring, a spin-coating process for TPE film fabrication, and a thermal bonding process using a pneumatic hot-press. UV treatment with an Excimer lamp prior to bonding drastically improves the bonding process. Optimized bonding parameters were characterized by measuring the burst load upon applying pressure and via profilometer-based measurement of channel deformation. Next, flow and long-term stability of the chip layout were measured using microparticle Image Velocimetry (uPIV). Finally, human endothelial cells were seeded in the microchannels to check biocompatibility and flow-directed cell alignment. The presented device is compatible with a real-time live-cell analysis system.Keywords:organ-on-a-chip;micro-pneumatics;PDMS-free;thermoplastic elastomers;layer-by-layer manufacturing
研究领域:
生物医学工程
·
细胞生物学
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DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2014
·Vol. 131
·期 15
·
IF 1.64
Minyu Rao,Qiangwei Su,Zhenzhen Liu,Peiqing Liang,Nan Wu,Changyun Quan,Qing Jiang
The purpose of this study was to study the mechanical properties of poly(methyl methacrylate) (PMMA)-based bone cement incorporated with hydroxyapatite (HA) nanoparticles after surface modification by poly(methyl methacrylate- co -γ-methacryloxypropyl timethoxysilane) [P(MMA- co -MPS)]. PMMA and P(MMA- co -MPS) were synthesized via free-radical polymerization. P(MMA- co -MPS)-modified hydroxyapatite (m-HA) was prepared via a dehydration process between silane and HA; the bone cement was then prepared via the in situ free-radical polymerization of methyl methacrylate in the presence of PMMA and P(MMA- co -MPS)–m-HA. Fourier transform infrared (FTIR) spectroscopy, 1 H-NMR, and gel permeation chromatography were used to characterize the P(MMA- co -MPS). Thermogravimetric analysis and FTIR were used as quantitative analysis methods to measure the content of P(MMA- co -MPS) on the surface of HA. The effect of the proportion of m-HA in the PMMA-based bone cement on the mechanical properties was studied with a universal material testing machine. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was also carried out to determine the cytotoxicity of the composite bone cement. The results showed that the surface modification of HA greatly improved the interaction between the inorganic and organic interfaces; this enhanced the mechanical properties of bone cement for potential clinical applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40587.
研究领域:
材料科学
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生物医学工程
✓ 已验证
DOI
高影响因子
ACS Omega
·
2020
·
IF 2.87
Yongxin Wang,Tongtong Duo,Xingmin Xu,Zhihong Xiao,Airong Xu,Rukuan Liu,Chaobo Jiang,Junning Lu
Poly(methyl methacrylate) (PMMA) is a thermoplastic polyester with excellent properties such as lightweight, low price, biocompatibility, and so on. However, its extensive utilization is restricted by the deficiencies of brittleness and poor mechanical properties. In this study, high-performance PMMA films enhanced by methylcellulose (MC) were fabricated by a simple procedure at ambient temperatures. The effects of PMMA/MC mass ratio and thermal compression treatment on mechanical properties (tensile strength and elongation) were systematically investigated. The PMMA/MC films showed remarkably enhanced mechanical properties compared with neat PMMA. The tensile strengths of the PMMA/MC (3:97) and PMMA/MC (1:1) films are higher than that of the PMMA/MC (9:1) film by about 471 and 83%, respectively. The mechanical properties were also improved after thermal compression treatment. Importantly, the PMMA/MC films could be recovered and reused. In addition, the morphologies, crystalline state, and chemical structures of the films were investigated by scanning electron microscopy, X-ray diffraction, and 13C NMR spectroscopy. The films are expected to be used as sustainable and potential alternatives to petroleum-based polymer film products because of their simple preparation procedure, high-performance mechanical properties, excellent recycling, eco-friendly features, and scale manufacture.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SOLAR ENERGY
·
2015
·
IF 3.469
Wei Zhou,Moo-Chin Wang,Xiujian Zhao
Poly(methyl methacrylate) (PMMA) doped with various amounts of the organic-dye 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) for luminescent solar concentrator (LSC) applications have been studied. The maximum wavelength of the emission peaks increases from 555 to 561 nm as the doped amount of organic-dye DCJTB increases from 2.08 (sample L3) to 8.33 mg (sample L5), which reveals a slight red-shift effect. The difference between the maximum wavelengths of the absorption and emission spectra ( λ s ) decreases from 58 to 47 nm as the doped amount of organic-dye DCJTB increases from 2.08 to 8.33 mg, which shows the Stokes shift. The short circuit photocurrent ( I sc ) increases from 11.68 to 14.11 mA/cm 2 as the doped amount of organic-dye DCJTB increases from 0 (undoped, sample L0) to 8.33 mg. The optical efficiency ( η opt ) also increases from 41.67% to 60.00% as the doped amount of organic-dye DCJTB increases. The maximum value of the incident photon-to-current conversion efficiency (IPCE) was about 9.0% at 526 nm when doped with 8.33 mg of organic-dye DCJTB (sample L5). The results of the present paper show through a well-conducted study on the optical properties of PMMA doped with organic-dye DCJTB that it can be suitable for LSC applications.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
CHINESE CHEMICAL LETTERS
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2010
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IF 0.643
Li Ping Wang,Li Min Zhao,Wen Zhi Li,Rui Qing Chu,Long Tan,Xiu Xiu Zhao,Gang Wang
The triple-shelled hollow spheres with optical properties were prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization. After removal the core templates of the poly (styrene), the hollow silica spheres were obtained. The coating process of poly (methyl methacrylate) (PMMA) on the hollow silica spheres surface via surface RAFT polymerization was performed subsequently. The polymers coated on the hollow spheres surfaces were end-functionalized by trithiocarbonate , and they were used as RAFT agent to proceed the chain extension polymerization using Tb complex as monomer . The samples were characterized by FT-IR, SEM and luminescence spectroscopy respectively. The results indicated that the triple-shelled hollow spheres had been prepared successfully and the average diameter of the hollow core was about 1 μm.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）