JOURNAL OF MATERIALS RESEARCH
·
2014
·Vol. 29
·期 10
·1153-1161
·
IF 1.815
Lin Chen,Longfei Li,Weifeng Liu,Yongzhen Yang,Xuguang Liu
A novel thermosensitive core/shell microgel with carbon microspheres (CMSs) cores was prepared by three steps. First, oxidized-carbon microspheres were obtained by mixed-acid oxidization. Second, the silane agent of 3-(trimethoxysilyl)-propyl methacrylate was used to functionalize the oxidized-carbon microspheres so as to generate the vinyl groups on the microspheres. Thereafter, the as-synthesized particles were used as seeds in the precipitation polymerization of N-isopropylacrylamide to introduce a thermosensitive polymer microgel shell onto the surfaces of the silanized-CMSs in the presence of an initiator and a crosslinker. The morphology and thermosensitive properties of the composite microspheres were characterized by field emission scanning electron microscopy, transmission electron microscopy, Fourier transformation infrared spectroscopy, thermogravimetry, and dynamic light scattering. Results indicate that the thickness of polymer layer could be adjusted by the crosslinking agent's concentration. The composite microgels had a low critical solution temperature at about 30 °C and exhibited strong thermosensitivity. The controlled release of a drug molecule (a model drug, acetosalicylic acid) was also investigated.
研究领域:
材料科学
·
生物医药
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Guangxu Ju,Danqian Wang,Yingzi Gu,Weining He,Yiming Niu,Guoxing Sun
Good thermal insulation performance is crucial for the application of cement materials, and reducing thermal conductivity is an effective strategy to enhance thermal insulation performance. Thermosensitive poly-N-isopropylacrylamide (PNIPAM) undergoes a phase transition around its lower critical solution temperature (LCST) of approximately 32 °C, and its incorporation can significantly improve the thermal insulation properties of cement. This study investigates the effects of adding PNIPAM in concentrations ranging from 0.3 % to 1.5 % on the thermal conductivity of cement-based materials at temperatures of 25 °C, 32 °C, and 37 °C. At 37 °C, the thermal conductivity of the cement sample decreased from 1.728 W/m·K to 0.811 W/m·K, representing a substantial reduction of 53.05 %. However, increasing the PNIPAM content also affected the hydration process of the cement mortars, leading to longer initial and final setting times and a slight decrease in both compressive and flexural strength. Additionally, the viscosity of the PNIPAM solution increased the overall viscosity of the cement mortar, resulting in reduced fluidity.
研究领域:
建筑材料学
·
热物理
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
IRANIAN POLYMER JOURNAL
·
2020
·Vol. 29
·期 10
·891-900
·
IF 1.707
Yang Mingxin,Hu Jie,Meng Jin,Shan Xiaojing
A hydrogel with dual thermo and photoresponsive characteristics was developed. Using poly( N -isopropylacrylamide) (PNIPAM) as the thermosensitive unit, the hydrogel network can undergo reversible swelling/shrinking behavior under different temperatures (20 °C and 37 °C) stimulation. A supramolecular host–guest complex composed of azobenzene (Azo) and α -cyclodextrin ( α -CD) was used as the photosensitive unit. Azo and α -CD can undergo reversible recombination/dissociation behavior under the stimulation of different wavelengths of light (365 nm and 430 nm). Methylene blue (MB) was selected as the model drug to measure the controlled release behavior of the hydrogel under different temperatures and photoirradiations. The experimental results showed that the hydrogel containing the thermosensitive component (PNIPAM) and the photosensitive component ( α -CD/Azo) released 69.3% and 47.2% of MB at 20 °C and 37 °C, respectively. Under the condition of light wavelengths at 430 nm and 365 nm, 73.2% and 65.6% of MB were released, respectively. The results showed that α -CD and Azo formed a supramolecular host–guest complex, which could undergo reversible binding/dissociation under the action of light stimulation, thereby controlling MB to enter and exit CD cavity. In addition, when the ambient temperature was lower or higher than the lower critical solution temperature of PNIPAM (LCST, 32 °C), the hydrogel underwent a responsive volume change to control the loading and release of MB molecules. So, combining the dual thermo and photoresponsibility, this smart hydrogel could be applied for multiple controlled release mechanisms.
研究领域:
材料科学
·
药学
✓ 已验证
DOI
高影响因子
Polymers
·
2019
·Vol. 11
·期 2
·302
·
IF 3.164
Boxiang Wang,Song Zhang,Yifan Wang,Bo Si,Dehong Cheng,Li Liu,Yanhua Lu
At present,Antheraea pernyisilk fibroin (ASF) has attracted research efforts to investigate it as a raw material for fabrication of biomedical devices because of its superior cytocompatibility. Nevertheless, native ASF is not easily processed into a hydrogel without any crosslinking agent, and a single hydrogel shows poor mechanical properties. In this paper, a series of ASF/poly (N-isopropylacrylamide) (PNIPAAm) composite hydrogels with different ASF contents were manufactured by a simple in situ polymerization method without any crosslinking agent. Meanwhile, the structures, morphologies and thermal properties of composite hydrogels were investigated by XRD, FTIR, SEM, DSC and TGA, respectively. The results indicate that the secondary structure of silk in the composite hydrogel can be controlled by changing the ASF content and the thermal stability of composite hydrogels is enhanced with an increase in crystalline structure. The composite hydrogels showed similar lower critical solution temperatures (LCST) at about 32 °C, which matched well with the LCST of PNIPAAm. Finally, the obtained thermosensitive composite hydrogels exhibited enhanced mechanical properties, which can be tuned by varying the content of ASF. This strategy to prepare an ASF-based responsive composite hydrogel with enhanced mechanical properties represents a valuable route for developing the fields of ASF, and, furthermore, their attractive applications can meet the needs of different biomaterial fields.Keywords:Antheraea pernyi;silk fibroin;hydrogel;thermosensitive;mechanical properties
研究领域:
生物材料学
·
高分子化学
·
组织工程学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 87
·70758-70765
·
IF 3.84
Leli Wang,Ying Wu,Yongjun Men,Jianan Shen,Zhengping Liu
Single electron transfer living radical polymerization (SET-LRP) was employed to prepare thermal-sensitive starch graft poly(N-isopropylacrylamide) (Starch-g-PNIPAM) with soluble Starch-Br as macro-initiator at molecular level. And Starch-g-PNIAPM with improved graft ratio and controlled length of graft chains were obtained. The effects of molar ratio of monomer to initiator and temperature on polymerization were investigated. The thermal responsibilities investigated by 1H NMR and UV showed that the LCST ranged from 31.5 °C to 23 °C with the increase of the length of PNIPAM chains and the concentrations of copolymers. Starch-g-PNIPAM hydrogels were gained when adding N,N′-methylenebisacrylamide as crosslinking agent and the swelling and deswelling behaviors were also investigated. The obtained hydrogels possess a high equilibrium swelling ratio as high as 1826%, and an extremely rapid shrinking rate as fast as losing more than 85% of water in 5 min.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Food Science & Technology
·
2021
·
IF 0
Shanshan Wang,Songbai Liu
In this study, formulation of soy protein- and gluten-based gel materials for 3D printing in a model study has been successfully developed employing thermosensitive cocoa butter to investigate its feasibility for preparing meat analogues. The influence of protein, starch, and sodium alginate on extrusion formability and printing accuracy was investigated. The extrusion formability of doughs of soy protein isolate was notably better than that of pea protein. Addition of appropriate amounts of cocoa butter, Tween-80, and sodium alginate was essential to achieve superior 3D printing performance. Thermosensitive cocoa butter provided fluidity to the doughs during 3D printing above room temperature and retained the shape upon solidification at room temperature. SEM-EDS, FT-IR, and solid-state NMR investigations revealed that the hydrogen bonding interaction of the soy protein and gluten network generated the fundamental continuous fibrous architecture of the gels. The developed strategy in this study would be valuable for formulating materials for 3D printing.
研究领域:
食品科学
·
材料科学
✓ 已验证
产品关联
DOI
JOURNAL OF POLYMER RESEARCH
·
2024
·Vol. 31
·期 9
·1-18
·
IF 2.6
Xu Wan,Zhang Huijuan,Huo Ting,Xiang Yongsheng,Ou Xiaojian,Sun Yuan,Sun Yuanjun,Chen Zhenbin
The excellent physical and chemical properties of palladium(Pd) have made its application and demand increase gradually. Therefore, it is important to develop a new material to efficiently separate and purify palladium from secondary sources to ensure its supply. In this work, a thermosensitive palladium smart imprinted polymer(Pd-T-SIP) was synthesized, which could achieve the efficient separation and purification of Pd. The microstructure and morphology of Pd-T-SIP were characterized. The experimental results showed that the Pd-T-SIP showed the maximum adsorption amount( Q ) of 0.1022 mmol/g for Pd(IV), the desorption rate( D ) was 83.09%, and it had good reusability. Theoretical studies showed that the adsorption process of Pd-T-SIP was suitable to be described by quasi-first-order model and Langmuir model, which indicated that the adsorption of Pd-T-SIP was monolayer adsorption. Finally, Pd-T-SIP was applied to the platinum group catalyst leach solution, and it could be found that its adsorption/desorption effect was more excellent, with its adsorption amount reaching 0.1558 mmol/L, desorption rate reaching 77.14%, and the palladium purity after one adsorption/desorption cycle increased from 13.75% to 30.62%, and the purity of platinum group metals increased from 40.29% to 73.56% after one adsorption/desorption cycle.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2019
·Vol. 92
·期 3
·618-627
·
IF 1.986
Zhu Hongyu,Zhu Meng,Shuai Shirong,Zhao Cong,Liu Yu,Liu Yuan,Li Xiaohong,Rao Zikun,Li Yang,Hao Jianyuan
The delicacy of nature prompted scientists to create functional or responsive biomaterials using existing natural components. Here we reported novel thermo-gelling hydrogels based on methyl poly (ethylene glycol)-poly (L-valine) (mPEG-L-PV) diblock copolymer solutions, which exhibited well-defined sol–gel transition at a temperature range from 10 °C to 40 °C. The β-sheet was the dominant secondary structure for poly(L-PV) block when the molecular weight of the polypeptide ranged from 277 Da to 1138 Da. The formation of mPEG–L-PV clear sol solutions was related to the stable nanostructures that were aggregated clusters of poly(L-PV) β-sheet filaments and stabilized by the hydrophilic PEG segments. The block length of poly(L-PV) significantly affected the secondary structures of polypeptide and the morphology of assembled filaments, which resulted in different thermo-gelling behavior of the copolymer solutions. The occurrence of sol–gel transition with temperature was primarily due to the dehydration effect of PEG block, whereas in the case of the copolymer with a lower molecular weight of poly(L-PV) block, the change of polypeptide secondary structures also contributed to the formation of the gel. This paper provides fundamental information about the strong dependence of polypeptide block length on the nano-assembly morphology as well as thermosensitive behavior of polypeptide-based hydrogels.
The block length of poly(L-PV) significantly affected the secondary structures of polypeptide and the morphology of assembled filaments, which resulted in different thermo-gelling behavior of the copolymer solutions.
研究领域:
生物材料
·
高分子化学
·
生物物理学
✓ 已验证
DOI
高影响因子
Science of Advanced Materials
·
2015
·Vol. 7
·期 5
·855-860
·
IF 2.598
Yu Huijuan,Xi Chenbin,Hu Jianhua,Du Ming,Yang Dong
An amphiphilic copolymer, PEG-b-PLA-b-(PAA-co-PNIPAM), was synthesized via atom transfer radical polymerization of tert-butyl acrylate and N-isopropyl acryamide using PEG-b-PLA-Br as a macroinitiator and CuBr/Me6 TREN as a catalytic
system, followed by selectively hydrolyzing tert-butyl groups to carboxyl groups. Then, doxorubicin (DOX) was loaded to the hydrophobic core, and the PAA segments were cross-linked by cystamine to get disulfide cross-linked and DOX loaded micelles. The transmission electron microscopy
images showed that the cross-linked DOX loaded micelles were spherical nanoparticles, with a mean diameter of 100 nm. The drug release behavior of the cross-linked DOX loaded micelles was redox responsive. The cumulative release amount of DOX was 33.1% with the presence of 10 mM of glutathione
(GSH) at 37 °C, much higher than that without the presence of GSH, which was only 4.3%. Furthermore, the cumulative release amount of DOX was 50.9% at 25 °C, higher than that at 37 °C, indicating that the cross-linked DOX loaded micelles were also thermo-sensitive.
研究领域:
药剂学
·
生物材料
·
肿瘤学
✓ 已验证
DOI
高影响因子
MACROMOLECULES
·
2012
·
IF 5.167
Chuanzhuang Zhao,Guangcui Yuan,Charles C. Han
Poly(N-isopropylacrylamide) (PNIPAM) microgels are adsorbable to the surface of polystyrene (PS) microspheres in the experimental temperature range (25–40 °C) and can induce aggregation of microspheres through the bridging mechanism. The bridging mechanism proceeds in two elementary steps: the first is an adsorption (negligible desorption relatively) of free microgel to one microsphere surface, and the next is a reversible connection of the adsorbed microgel to another microsphere surface. The surface coverage is found as an important factor in triggering the stabilization, aggregation, and gelation of the mixtures. And most importantly, the nonnegligible dynamic disconnection of a bridge is the essential prerequisite for structure or state transition. For mixtures with the same concentration of microsphere, depending on the concentration of microgel, various transitions can be induced by changing temperature, including the transition from a weaker gel to a stronger gel, from a fluid to a bridging gel and from a depletion gel to a bridging gel.
研究领域:
材料科学
·
胶体化学
✓ 已验证
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2022
·Vol. 9
·期 8
·1802-1811
·
IF 7.779
Zhi-Han Zuo,Song-Lin Jiang,Zhi-Hao Zhang,Jinhui Liang,Junhao Li,Zhao-Qing Liu,Yibo Chen
How electron traps in a host matrix impact the fluorescence intensity ratio (FIR) thermometry performance in inorganic phosphors is still unclear. In this work, relationships between temperature-dependent photoluminescence, fluorescence intensity ratio-based optical thermometry performance, and concentration of the electron traps have been thoroughly investigated in a Mn-doped ZnGa2O4 spinel system. The results reveal that the sample with a higher concentration of electron traps shows a thermometry sensitivity (Sr) of 3.47% K−1 read from the FIR of the green channel (Mn2+) and the red channel (Mn4+), which is over twice higher than that of the sample with a lower concentration of electron traps. Detailed photoluminescence, thermoluminescence, and first-principles calculations demonstrate that the performance enhancement is dominantly caused by a selective thermally induced emission compensation through the antisite defects in the ZnGa2O4 host. The defects act as electron traps and compensate for the intensity decline of the green channel by releasing electrons at high temperatures while leaving the red channel unaffected, thus increasing the FIR value and the sensitivity. This work shows a significant enhancement effect of the electron traps on the FIR thermometry performance in ZnGa2O4:Mn and provides a novel strategy for thermometry performance enhancement through the manipulation of traps.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2023
·
IF 3.4
Hejun Zhan,Yongzhi Chen,Long Huang,Chao Yang,Yalan Zhong,Lihua Wang,Xulin Jiang
Novel water-soluble methylated chitins (MCHs) were synthesized homogeneously in aqueous alkaline solution. The relatively mild reaction conditions resulted in the MCH with high degree of acetylation (DA >0.76). The chemical structure of the obtained MCHs was analyzed and the degree of methylation substitution (DS) and DA were determined by proton NMR in both D 2 O and 20% DCl/D 2 O. The MCH aqueous solutions (DS = 0.46 ~ 0.71) showed a reversible thermosensitive sol–gel–sol transition upon heating and cooling. The gel transition temperature of these MCHs (in the range of 15–85 °C) increased with increasing DS and decreasing polymer concentration. Thermal runaway has been an important safety issue impeding the development of high-energy-density zinc-ion batteries. A smart thermosensitive reversible electrolyte was prepared based on this MCH for the aqueous zinc-ion battery to prevent thermal runaway. When the temperature of zinc-ion battery rises or even gets out of control, the thermosensitive electrolyte can quickly gel and inhibit the migration of zinc ions, resulting in increase of the internal resistance and realizing intelligent and efficient thermal self-protection. Thus the novel thermosensitive methylated chitin shows promise for safe aqueous zinc-ion batteries. Graphical
研究领域:
材料科学
·
能源存储
·
化学工程
✓ 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）