INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
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2020
·
IF 4.947
Xiu Li,Yimin Xuan,Qiang Li
Conventional microchannels provide effective chip cooling with constant flow rate and this comes at the cost of high pumping power consumption. Considering the dynamic heat load in reality, a self-adaptive microchannel cooling is desired for regulating the flow rate to diminish the operational cost while preserving the inherent cooling effectiveness. Taking the advantages of easy synthesis, well tunable lower critical solution temperature (LCST) and remarkable mechanical strength, this paper reports the self-adaptive microchannel cooling with the thermal-sensitive nanocomposite (NC) P(MEO 2 MA- co -OEGMA) hydrogel. A novel route is developed to integrate the hydrogel with the chip using template-aided imprint molding and in situ polymerization. Circular hydrogel is elaborately designed and anchored firmly in the channel. The cooling performance is tested with a custom test vehicle under different operating conditions. The hydrogel acts as a smart valve and tailors the flow rate from 0.14 mL/s to 0.46 mL/s based on heat load variation. Compared with conventional channels, heat flux of 100 W/cm 2 can be extracted with similar temperature rise while the coefficient of performance (COP) is improved by an order of magnitude. The transient characteristics and repeatability are also validated. The self-adaptive scheme offers both effective and economical liquid cooling for modern electronic devices.
研究领域:
材料科学
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电子工程
·
热管理技术
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产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 33
·27485-27493
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IF 3.289
Yunze Wang,Haibo Lin,Zhu Xiong,Ziyang Wu,Xuemin Yu,Yi Wang,Fu Liu
An interesting PVDF membrane with unusual thermoresponsive behavior was prepared by the incorporation of P(OEGMA-co-VTMOS). The P(OEGMA-co-VTMOS) copolymer was first in situ synthesized in a PVDF/triethyl phosphate (TEP) casting solution. A P(OEGMA-co-VTMOS) network was assembled in the PVDF membrane through hydrolysis and condensation during phase inversion. PVDF/P(OEGMA-co-VTMOS) in organic solvent demonstrated a typical LCST around 35 °C, reflecting the reversible transition of the coil-to-globule conformation. Microphase separation was responsible for the appearance of turbidity of the casting solution. FTIR, XPS, TGA and SEM confirmed the surface enrichment of the copolymer, especially in the membrane bottom. The hydrophilicity and protein anti adsorption were improved despite the temperature variation. In particular, AFM in aqueous media was conducted to determine the reversible morphology and water channel variation under heating and cooling. Different from common thermoresponsive membranes, the so-modified PVDF membranes exhibit a reversible abnormal change of pure water flux and BSA rejection with temperature. The intriguing thermoresponsive behavior and mechanism of the modified PVDF membrane was thoroughly investigated from the aspects of PVDF/TEP casting solution, membrane morphology in aqueous media and water/BSA filtration performance.
研究领域:
材料科学
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膜技术
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高分子化学
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DOI
高影响因子
Polymers
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2020
·Vol. 12
·期 11
·2482
·
IF 3.426
Fei Song,Zhidan Wang,Wenli Gao,Yu Fu,Qingrong Wu,Shouxin Liu
Novel temperature/reduction dual stimulus-responsive triblock copolymers, poly [2-(2-methoxyethoxy) ethyl methacrylate-co-oligo (ethylene glycol) methacrylate]-b-(L-polylactic acid)-SS-b-(L-polylactic acid)-b-poly[2-(2-methoxyethoxy) ethyl methacrylate-co-oligo(ethylene glycol)methacrylate] [P(MEO2MA-co-OEGMA)-b-PLLA-SS-PLLA-b-P(MEO2MA-co-OEGMA)] (SPMO), were synthesized by ring opening polymerization (ROP) of L-lactide and 2,2’-dithio diethanol (SS-DOH), and random copolymerization of MEO2MA and OEGMA monomers via atom transfer radical polymerization (ATRP) technology. The chemical structures and compositions of the novel copolymers were demonstrated by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR). The molecular weights of the novel copolymers were measured by size exclusive chromatography (SEC) and proved to have a relatively narrow molecular weight distribution coefficient (ÐM ≤ 1.50). The water solubility and transmittance of the novel copolymers were tested via visual observation and UV–Vis spectroscopy, which proved the SPMO had a good hydrophilicity and suitable low critical solution temperature (LCST). The critical micelle concentration (CMC) of the novel polymeric micelles were determined using surface tension method and fluorescent probe technology. The particle size and morphology of the novel polymeric micelles were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The sol–gel transition behavior of the novel copolymers was studied via vial flip experiments. Finally, the hydrophobic anticancer drug doxorubicin (DOX) was used to study the in vitro release behavior of the novel drug-loaded micelles. The results show that the novel polymeric micelles are expected to become a favorable drug carrier. In addition, they exhibit reductive responsiveness to the small molecule reducing agent dithiothreitol (DTT) and temperature responsiveness with temperature changes.Keywords:temperature/reductive dual-stimulus responsiveness;block copolymers;amphiphilic;ring-opening polymerization;atom transfer radical polymerization
研究领域:
高分子化学
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药物递送系统
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材料科学
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产品关联
DOI
PubMed
高影响因子
COLLOID AND POLYMER SCIENCE
·
2016
·Vol. 295
·期 2
·327-340
·
IF 1.89
Guo Yi,Dong Xiuyan,Ruan Wenjing,Shang Yazhuo,Liu Honglai
The interactions between poly(2-(2-methoxyethoxy)ethyl methacrylate 90 -co-oligo(ethylene glycol) methacrylate 10 ) (P(MEO 2 MA 90 -co-OEGMA 10 )) and sodium dodecyl sulfate (SDS) or dodecyltrimethyl ammonium bromide (DTAB) in aqueous solutions with and without salt are explored. The influence rule of surfactant on thermo-sensitive behavior of polymer and the corresponding mechanism is revealed. The results have suggested that both surfactants have moderate interactions with P(MEO 2 MA 90 -co-OEGMA 10 ), which result in the formation of P(MEO 2 MA 90 -co-OEGMA 10 )/surfactant complexes. Meanwhile, the self-aggregation of polymer chains is hindered causing the lower critical solution temperatures (LCSTs) increase due to the electrostatic repulsion and “locking water” effect caused by surfactant head groups. Tetra-n-butylammonium bromide (Bu 4 NBr) and tetra-n-propylammonium bromide (Pr 4 NBr) can associate with SDS and form mixed micelles. Interestingly, the formed mixed micelles apt to attach on the polymer chain and the polymer-bound necklace-like structure forms in the ternary polymer/salt/surfactant system. The structure of the complexes formed in the ternary system is confirmed by 2D NOESY NMR and the interaction mode is proposed. The relations between LCST of different systems and surfactant concentrations are also established quantitatively.
研究领域:
高分子化学
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物理化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Acta Biomaterialia
·
2013
·
IF 5.093
Y. Deng,X. Zhang,X. Zhao,Q. Li,Z. Ye,Z. Li,Y. Liu,Y. Zhou,H. Ma,G. Pan,D. Pei,J. Fang,S. Wei
Realization of the full potential of human induced pluripotent stem cells (hiPSC) in clinical applications requires the development of well-defined culture conditions for their long-term growth and directed differentiation. This paper describes a novel fully defined synthetic peptide-decorated substrate that supports self-renewal of hiPSC in commercially available xeno-free, chemically defined medium. The Au surface was deposited by a poly(OEGMA- co -HEMA) film, using the surface-initiated polymerization method (SIP) with the further step of carboxylation . The hiPSC generated from umbilical cord mesenchymal cells were successfully cultured for 10 passages on the peptide-tethered poly(OEGMA- co -HEMA) brushes for the first time. Cells maintained their characteristic morphology, proliferation and expressed high levels of markers of pluripotency, similar to the cells cultured on Matrigel™. Moreover, the cell adhesion could be tuned by the pattern and peptide concentration on the substrate. This well-defined, xeno-free and safe substrate, which supports long-term proliferation and self-renewal of hiPSC, will not only help to accelerate the translational perspectives of hiPSC, but also provide a platform to elucidate the underlying molecular mechanisms that regulate stem cell proliferation and differentiation via SIP technology.
研究领域:
干细胞研究
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生物材料
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再生医学
·
聚合物化学
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DOI
PubMed
高影响因子
MACROMOLECULAR RESEARCH
·
2013
·Vol. 21
·期 12
·1338-1348
·
IF 1.639
Xu Yiting,Xie Jianjie,Chen Lingnan,Yuan Conghui,Pan Yinyin,Cheng Ling,Luo Weiang,Zeng Birong,Dai Lizong
A novel organic/inorganic hybrid amphiphilic random copolymer poly(methacrylate isobutyl POSS- co -N-isopropylacrylamide- co -oligo(ethylene glycol) methyl ether methacrylate- co -2-vinylpyridine), poly(MAPOSS- co -NIPAM- co -OEGMA- co -2VP), was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The self-assembly behavior of random copolymers in aqueous solution was investigated by dynamic light scattering (DLS) as well as transmission electron microscopy (TEM). The results indicate the novel random copolymer in water could self-assemble into spherical aggregates and the self-aggregate size displays a remarkable dependence on pH. The stimuli-responsive characteristics of these assembles were tested by means of UV-vis spectra, DLS and TEM. There is a critic Zn 2+ concentration over which the aggregates can be coordinated into well-define spherical aggregate clusters. The critic Zn 2+ concentration can be tuned finely through adjusting solution concentration or 2VP amount. Results from UV-vis and DLS reveal that the copolymer solutions exhibit a sharp and intensive lower critical solution temperature (LCST). Some factors such as the solution concentration, molecular weight, pH and copolymer generation, which could affect the cloud point, were studied systematically. The essentially predetermined LCST can be achieved by altering the content of 2VP or pH. In addition, these novel hybrid aggregates can undergo an association/disassociation cycle with the heating and cooling of solution and the degree of reversibility shows a strong concentration dependence. As a novel organic-inorganic hybrid material which can respond to multiple external stimuli including temperature, pH, metal ions with sharp stimuli-responsive behaviors, it is potentially used for biomedicine, catalysis, diagnostics, bioseparations, biosensors and for fundamental investigation.
研究领域:
材料科学
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高分子化学
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生物医药
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2018
·Vol. 10
·期 2
·228-234
·
IF 4.927
Chao Chen,Xiaofeng Guo,Jinhong Du,Bonnie Choi,Houliang Tang,Anchao Feng,San H. Thang
Miktoarm star (MAS) polymers are polymers with a number of distinct arms connected to a central core. Owing to their exclusive structure, MAS polymers have been extensively studied in recent years. To exploit their biomedical applications the combination of nucleic acids, peptides and saccharides are desired. In this study, RAFT polymerization of three monomers with markedly different properties, N,N-dimethylaminoethyl methacrylate (DMAEMA, cationic), n-butyl methacrylate (BMA, hydrophobic) and oligo(ethylene glycol) methyl ether methacrylate (OEGMA, hydrophilic) was conducted using an RGD peptide based RAFT agent as a chain transfer agent (RGD-CTA). With a disulphide dimethacrylate (DSDMA) redox-cleavable cross-linker, the above linear polymers were combined via an “arm-first” technique to access MAS polymers containing peptide arms. These MAS polymers showed excellent biocompatibility, cell staining performance and rapid redox responsiveness. The novel MAS polymers have potential as a prospective platform for intracellular drug/gene delivery for cancer therapy.
研究领域:
高分子化学
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材料科学
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生物医学工程
·
药学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2022
·
IF 9.417
Lingling Pan,Dawei Jiang,Luqi Pan,Zhizhen Meng,Yangyang Zhuang,Yueyue Huang,Fanrong Ye,Changcan Shi,Jie Chen,Jingye Pan
Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection and causes high ratios of morbidity and mortality worldwide. Although many potential therapeutic targets have been reported, the therapeutic effect needs to be further improved. Herein, we report a strategy to specifically target inflammation site via anti-ICAM-1 antibody bonded antibacterial peptides polymeric nanoparticle. Antibacterial peptide (KR-12) grafted amphipathic PCL- b -P(OEGMA- co -AMA)- g -Cys-KR-12 block copolymer and PCL- b -P(OEGMA- co -AMA)- g -biotin block copolymer were synthesized by ring-opening polymerization and click chemistry. Then, antibacterial peptides polymeric nanoparticles (AMPNP) were prepared by co-assembly of amphipathic PCL- b -P(OEGMA- co -AMA)- g -Cys-KR-12 and PCL- b -P(OEGMA- co -AMA)- g -biotin in aqueous solution. Intercellular adhesion molecule-1 (ICAM-1) is highly expressed on the surface of inflammatory endothelial cells, and the anti-ICAM-1 antibody can specifically bind to it. To obtain the anti-ICAM-1-AMPNP nanoparticles, biotinylated anti-ICAM-1 antibodies were bonded on the surface of AMPNP nanoparticles through the biotin-avidin system. The anti-ICAM-1-AMPNP nanoparticles had low systemic toxicity and exhibited ideal antibacterial property against drug-resistant bacteria, Gram-negative bacteria and Gram-positive bacteria. The anti-ICAM-1-AMPNP nanoparticles exhibited favorable targeting capabilities to inflammation endothelial cells in vitro and significantly reduced the inflammatory response of CLP mice in vivo . The present investigation might provide a specific strategy for targeting combating sepsis with anti-ICAM-1-AMPNP nanoparticles.
研究领域:
药学
·
纳米技术
·
感染病学
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免疫学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Gels
·
2022
·Vol. 8
·期 9
·570
·
IF 4.432
Qingrong Wu,Yu Fu,Wanying Yang,Shouxin Liu
Hydrogel is a good drug carrier, widely used in the sustained-release aspect of tumor drugs, which can achieve the continuous release of drugs to the tumor sites. In this study, diethylene glycol monomethyl ether methacrylate (MEO2MA) and poly (ethylene glycol) methyl ether methacrylate (OEGMA) are temperature-sensitive monomers. N-Methacryloyl-L-Histidine (Mist) is pH sensitive monomer and ligand for metal coordination bond. The temperature-sensitive monomers and pH sensitive monomer with stereocomplex of modified polylactic acid (HEMA-PLLA30/PDLA30) were mixed, under 2,2’-azobis (2-methylpropionitrile) (AIBN) as radical initiator, polymer was formed by free-radical polymerization. The polymer was then immersed in ZnSO4solution, the imidazole group of Mist monomer forms a tridentate metal coordination bond with Zn2+, temperature/pH double-responsive and physical double-crosslinked hydrogel was finally obtained. Comparing the hydrogen bond hydrogel, hydrogen bond and metal coordination bond double crosslinking hydrogel, metal coordination bond hydrogel, testing thermal stability, viscoelasticity, swelling, and morphology of three hydrogels. In addition, using UV-Visible spectroscopy (UV-Vis) to test the sustained release of the hydrophobic drug doxorubicin hydrochloride (DOX-HCl) in the human tumor environment (37 °C, pH = 5). We found that the temperature/pH double-responsive and physical double-crosslinked hydrogel had the most potential for the sustained drug release.
研究领域:
材料科学
·
药学
·
生物医学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）