Materials
·
2018
·Vol. 11
·期 5
·705
·
IF 2.467
Bing Yu,Tingting Xue,Long Pang,Xiulan Zhang,Youqing Shen,Hailin Cong
Monodisperse cross-linked porous poly (methyl methacrylate) (PMMA) microspheres (~2.5 μm in diameter) were prepared by using an improved two-step seed swelling polymerization method with monodisperse micron-grade PMMA microspheres seeds. The porous PMMA microspheres with diverse surface morphology and pore structure were obtained by tuning porogen systems. The monodisperse porous PMMA microspheres, which were prepared using toluene:dibutylphthalate (DBP) = 1:1 (v/v) as a porogen system, had the smallest pore size and the largest specific surface area. Then, the monodisperse porous PMMA microspheres were subjected to high-performance liquid chromatography. The liquid chromatographic column filler successfully realized complete separation of arginine, glycine and glutamic acid, and the separation effect was good. The porous PMMA microspheres provide a new material for the separation of amino acids by liquid chromatography.Keywords:poly (methyl methacrylate), seed swelling polymerization;porous microspheres;high-performance liquid chromatography
研究领域:
材料科学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
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
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2017
·
IF 1.174
Ting Zhang,Minmin Chen,Yu Zhang,Yi Wang
Aiming to identify the validity of fabricating microencapsulated phase change material (PCM) with polymethylmethacrylate (PMMA) by ultraviolet curing emulsion polymerization method using iron (III) chloride as photoinitiator, SA/PMMA microcapsules were prepared and various techniques were employed to determine the ignition mechanism, structural characteristics and thermal properties of the composite. The results shown that the microcapsules containing SA with maximum percentage of 52.20 wt% formed by radical mechanism and only physical interactions existed in the components both in the prepared process and subsequent use. The phase change temperatures and latent heats of the microencapsulated SA were measured as 55.3 °C and 102.1 J·g − 1 for melting, and 48.8 °C and 102.8 J·g − 1 for freezing, respectively. Thermal gravimetric analysis revealed that SA/PMMA has good thermal durability in working temperature range. The results of accelerated thermal cycling test are all shown that the SA/PMMA have excellent thermal reliability and chemical stability although they were subjected 1000 melting/freezing cycles. In summary, the comparable thermal storage ability and good thermal reliability facilitated SA/PMMA to be considered as a viable candidate for thermal energy storage. The successful fabrication of SA/PMMA capsules indicates that ferric chloride is a prominent candidate for synthesizing PMMA containing PCM composite.
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
·
2015
·Vol. 5
·期 32
·25450-25456
·
IF 3.84
Wenqiong Ye,Ling Zhang,Chunzhong Li
SiO2@poly(methyl methacrylate)–reduced graphene oxide (SiO2@PMMA–rGO) composites with outstanding thermal stability, robust mechanical performance and excellent conductivity have been prepared by dispersion polymerization and electrostatic assembly based colloidal blending. The simultaneous construction of well-segregated silica structures and interconnected graphene networks, not only efficiently avoids agglomeration of the incorporated nanofillers, but also ensures enhanced interfacial adhesion between the fillers and the PMMA matrix, endowing the resultant composite with high performance. Specifically, compared to the host polymer, the composite with collaborative structure exhibits high thermal stability, i.e. the decomposition temperature increases by 80 °C and shows robust mechanical properties with a 108% increase in modulus and a 125% improvement in hardness. Besides, an ultra-low percolation threshold of 0.23 vol% is also achieved and the electrical conductivity reached 15.1 S m−1 with only 2.7 vol% graphene loading, which is ∼8 orders of magnitude higher than that for SiO2–PMMA–rGO (where SiO2, PMMA and rGO were simply compounded without forming synergetic structures) with the same rGO loading. These results demonstrate that the SiO2@PMMA–rGO composite has great potential to be applied as mechanical, thermal, and electrical materials.
研究领域:
材料科学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 36
·28633-28642
·
IF 3.84
Huaizhong Shen,Yuxin Wu,Liping Fang,Shunsheng Ye,Zhaoyi Wang,Wendong Liu,Zhongkai Cheng,Junhu Zhang,Zhanhua Wang,Bai Yang
A rapid and cost effective method has been developed to fabricate 3 dimensional (3D) ordered structures by photo-generating silver networks inside a 1D layered heterogeneous laminate composed of poly(vinyl alcohol) (PVA) and poly(methyl methacrylate) (PMMA). By designing the photo-mask meticulously, the silver nanoparticles (NPs) produced by UV light aggregate to form frameworks in different forms, which perform as the anisotropic component, i.e. the building blocks, thus converting the 1D structure into 3D. Formation of silver NPs increases the refractive index (RI) of the PVA layers, thus bringing optical change to the 1D laminar structure, which allows us to trace the silver formation process by measuring the change of RI value and reflectance spectra. The 1D layered structure is a good building matrix for 3D construction because the total number of layers and the layer thickness can be finely tuned flexibly which allow us to further study the various properties caused by the structural modulation. By utilizing photo-reactive silver ions, an innovative strategy of fabricating 3D structures through in situ photo-generating silver building blocks inside the laminar matrix is established, which makes it possible to fabricate 3D micro/nano composite materials with potential applications in fields such as sensors and photonic meta-materials.
研究领域:
材料科学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2015
·Vol. 22
·期 4
·1-6
·
IF 1.92
Wang Guo-Xiang,Lu Mang,Hou Zhao-Hui,Yang Chang-An,Liang En-Xiang,Liu Li-chao,Wu Hu,Li Xiang-Lei,Xu Yi-Xue
The photo-induced atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was successfully carried out in ionic liquid at ambient temperature with ethyl 2-bromoisobutyrate as initiator and CuBr 2 /N,N,N′,N′,N″-pentamethyldiethylenetriamine as the complex catalyst system. In this system, TiO 2 was used as photocatalyst. The well-controlled poly(methyl methacrylate) (PMMA) was obtained, as evidenced by the controlled molecular weights of the obtained. The prepared PMMA had narrow molecular weight distributions. The polymerizations were manipulated by turning on/off the light. The chemical structure of the obtained PMMA was characterized by 1 H NMR. Chain extension experiment with bromine-atom-ended PMMA as macroinitiator was carried out successfully to verify the living nature of photo-induced ATRP of MMA.
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
Polymer Chemistry
·
2018
·Vol. 9
·期 45
·5470-5475
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IF 4.927
Shanshan Chen,Liman Hou,Qiliao Wang,Dewen Dong,Ning Zhang
We demonstrate the first application of Lewis pair-mediated polymerization (LPP) in the efficient synthesis of cylindrical molecular brushes bearing poly(methyl methacrylate) and polylactone side chains. Poly(N-heterocyclic olefin) (poly(NHO)) as a macroinitiator precursor was firstly prepared by the reversible addition–fragmentation chain transfer (RAFT) polymerization of N-vinylimidazolium iodide and successive deprotonation in the presence of a strong base. Poly(NHO) together with Al(C6F5)3 can jointly promote the polymerization of methyl methacrylate and δ-valerolactone, leading to the formation of PMMA and polylactone side chains along the backbone via the grafting-from approach. NMR, GPC, AFM characterization and polymerization dynamic investigation indicate the successful formation of side chains and the resulting stretched conformation of the polymer backbone. DSC characterization reveals that molecular brushes have a higher glass transition temperature than their linear counterpart because of the branched architecture of molecular brushes. The current strategy represents a new avenue for the application of LPP and provides potential in the synthesis of polymers with well-defined topological structures.
研究领域:
高分子化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2024
·Vol. 81
·期 13
·12027-12043
·
IF 3.1
Wu Weilong,Feng Shihao,Ouyang Qin,Yang Zengzhuan,He Liu,Huang Qing
Polymethyl methacrylate (PMMA) is an important thermoplastic polymer and a versatile lithographic resist. However, the low heat resistance and low dry-etch resistance seriously restricts the application of PMMA in high-end devices and advanced nanolithography. Herein, methyl methacrylate (MMA) was copolymerized with two comonomers 1-adamantyl methacrylate (AdMA) and 1-acryloyloxy-3-hydroxyadamantane (HAdMA), and a series of copolymers P(AdMA-co-MMA) and P(HAdMA-co-MMA) with different contents of HAdMA were prepared. The UV–Vis, ellipsometer, DSC, TG, and TG–MS techniques were employed to investigate the effects of adamantyl and hydroxyadamantyl substituents on the optical and thermal properties of PMMA. The introduced hydroxyadamantyl not only significantly enhanced the refractive index, but also maintained the high transparency and low dispersion of PMMA. The glass transition temperature and thermal stability of PMMA were also greatly improved by the hydroxyadamantyl. The initial decomposition temperature of PMMA increased from 160 to about 260 ℃ after introducing 5% HAdMA. HAdMA was more effective than AdMA in improving the optical and thermal properties of PMMA. The novel P(HAdMA-co-MMA) copolymer has overcome the shortcomings of traditional PMMA and is anticipated to significantly broaden its range of applications.
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
COLLOID AND POLYMER SCIENCE
·
2020
·Vol. 298
·期 4
·385-393
·
IF 1.536
Tang Yunlu,Xiao Chao,Ding Jiwan,Hu Kun,Zheng Kang,Tian Xingyou
High thermal conductivity polymer composites have increased application in modern electronics. To achieve high thermal conductivity at relatively low filler content, two critical approach are used: surface modification of the filler and construction of thermal conductive network in polymer composites. This article provided a new simple and feasible method to modify h-BN consisting of physical absorption of polyvinylpyrrolidone (PVP) and hydrolysis of tetraethyl orthosilicate (TEOS). Then, SiO 2 @BN/PMMA composites were fabricated via solution-mixing and hot compression. The surface modification of BN enhanced the interface interaction between adjacent BN, which led to reduced thermal resistance and phonon scattering. The solution-mixing and hot compression process ensured the formation of thermal conductive pathway at the same time. The highest thermal conductivity of 40 vol% SiO 2 @BN/PMMA composite reached 5.583W /m K, which exhibited 3292% and 200% enhancement compared with the pure PMMA and melt-mixing BN/PMMA composites, respectively.
研究领域:
材料科学
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热传导工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2018
·
IF 3.909
Manli Yang,Liang Wang,Yanzhi Xia
The graft copolymerization of methyl methacrylate (MMA) onto alginate was carried out in aqueous media by initiators of ammonium persulphate under a nitrogen gas atmosphere. Then, the grafting of PMMA chains onto the alginate backbone was confirmed through the study of Fourier transform infrared, X-ray diffraction, scanning electron microscopy and 1 H nuclear magnetic resonance spectroscopy . At last, a thin and transparent polymethyl methacrylate grafted alginate film with high strength was obtained by the casting method. The effect of MMA/SA ratio or percentage of graft (G%) on mechanical properties, thermal stability (thermogravimetric analysis/differential thermogravimetry analyses), color, opacity and water resistance of composite films were characterized. Results showed the homogeneous transparent films could be obtained while G% was lower than 8.64%. After being grafted by PMMA, the tensile strength of the films was distinctly improved by 205.3%, as well the elongation at break (E%) by 41.7% while the MMA/SA (g/g) is 0.3. On the other hand, water resistance, thermal stability and crystallinity of the films were improved, however, the transparency was slightly decreased.
研究领域:
材料科学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2022
·
IF 4.432
Xinyue Zhang,Haimo Zhang,Min Zuo,Jun Zhong,Xuanyu Shi,Shihao Sun,Li Yang,Yihu Song,Qiang Zheng
The effect of selective distribution and migration behavior of two kinds of poly (methyl methacrylate)-grafted nanoclays (PMMA- g -clay) on the phase behavior of PMMA/poly (styrene- co -acrylonitrile) (SAN) blends is investigated. The grafting ratios of our two modified nanoclays are similar, but their grafting density and grafted chain lengths are different, resulting in their different initial locations and subsequent migration behaviors in the blend matrix. The PMMA- g -clay(d) nanosheets (NSs) with relatively dense and short chains are always distributed at the interfacial region and further form the percolation networks to block the concentration fluctuation and retard the domain coarsening of blend matrix more remarkably, while the PMMA- g -clay(s) NSs with relatively sparse and long chains are distributed at first in the SAN-rich domains and subsequently move slowly to the interfacial region, resulting in their inhibition of the phase separation for PMMA/SAN blend from retarding SAN chains’ viscous diffusion to their gradual interfacial aggregation for stabilizing the morphology. The variation of storage modulus for three systems in low frequency and long-time regimes are also affected by different selective distributions of two grafted clay NSs in PMMA/SAN blend matrix.
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
Materials Today Sustainability
·
2022
·
IF 7.244
X. Huang,Y. Tuersun,M. Huang,W. Lin,W. Qiu,S. Chu
Efficient thermal management materials are important for the proper operation of integrated circuits. In this work, the high-yield preparation of hydroxylated boron nitride nanosheets (BNNSs) was achieved by high-temperature ablation followed by ultrasonic exfoliation without the use of highly toxic solvents. The small-sized BNNSs have similar phonon vibration properties as the large-sized MXene , and they self-assemble by electrostatic adsorption on PMMA particles to form hybrid spheres. The appearance of thermal percolation threshold indicates the successful construction of thermal conductivity pathway. The exclusion effect is more pronounced for PMMA microspheres with a larger radius, and the best thermal conductivity of 4.13 W/m·K was achieved for the composite with 20 wt% nanosheet filling. The composite exhibited good thermal performance both in the finite element model and when used as an LED heat sink. Furthermore, the incorporation of fillers can also effectively improve the thermal stability and mechanical properties of the composite. Our study provides a facile and environmental exfoliation approach of h-BN and a new strategy for the preparation of high thermal conductivity electronic packaging materials.
研究领域:
材料科学
·
热管理技术
✓ 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）