MACROMOLECULAR MATERIALS AND ENGINEERING
·
2022
·Vol. 308
·期 5
·2200559
·
IF 4.402
Lingcheng Meng,Jinling Zhang,Shuang Zhao,Desheng Qi,Pan Xu,Shuoqi Wu,Le Wang,Xigui Yue,Zhenhua Jiang
Polyaryletherketone is a kind of special engineering plastics with excellent comprehensive properties, high strength, good stability, and almost insoluble in any common solvent except concentrated sulfuric acid at room temperature. However, its high processing temperature also hinders its application and development in the foam. Here, a series of polyetheretherketone (PEEK) and diphenyl polyetheretherketone (PEDEK) composite foams are prepared by temperature induced phase separation, using diphenyl sulfone as solvent. The microstructure, thermal and mechanical properties of PEEK and PEDEK foam are compared. Highly porous PEEK and PEDEK foams with densities ranging from 0.13 to 0.25 g cm −3 , with compressive strength ranging from 0.68 to 2.6 MPa, respectively, are produced. Meanwhile, the introduction of diphenyl structure can effectively improve the performance of PEEK foams at high temperature. It is found that PEDEK foam has a higher operating temperature than PEEK, and the compressive strength of 0.24 g cm −3 foam is still ≈1 MPa at 200 °C.
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
OPTICS EXPRESS
·
2024
·Vol. 32
·期 25
·44103-44114
·
IF 3.2
Jianxia Qi,Yuchong Ren,Kangzhe Zhao,Xinyue Li,Wanxuan Chang,Chengyun Zhang,Qingyan Han,Wei Gao,Yongkai Wang,Jun Dong
Plasmonic dimers have a very wide range of applications as a unique platform for studying the fundamental effects of plasmonics. Most dimer structures are prepared by chemical methods and direct-writing methods, such as coupling agents and lithography. These methods are often complex and expensive. Here, we prepared Au nanospheres (AuNSs) by layer-by-layer (LBL) deposition, used polymethyl methacrylate (PMMA) as a spacer layer, and then annealed the deposited AuNSs to orient the assembly and integrate them together. In this paper, suitable PMMA spin coating conditions and optimal annealing temperatures were explored, and large-scale AuNSs-PMMA-AuNSs(NSs-P-NSs) composed of vertical Au nanosphere dimers were prepared successfully. The detection limits of this substrate can reach 4 × 10−12 M/L and 4 × 10−10 M/L for Rhodamine 6 G (R6G) and Crystal Violet (CV), respectively, demonstrating excellent Raman activity. In addition, the sensitivity of detecting aspartame (APM) is 0.015625 g/L. This method is not only simple to operate but also allows the preparation of a large-scale uniform substrate with excellent detection capabilities.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2020
·Vol. 22
·期 7
·1220-1229
·
IF 3.117
Xiaoyan Zhang,Yu Tang,Yifeng Wang,Liming Shen,Arunava Gupta,Ningzhong Bao
A simple one-pot heat-up method has been developed to synthesize Cu4SnS4 nanoplates with highly exposed (002) surfaces. Temperature-dependent phase transformation from monoclinic Cu1.94S to orthorhombic Cu4SnS4, and eventually to partially triclinic Cu2SnS3 has been observed. It is revealed that the Sn4+ existing in the laminar structure of Cu1.94S nanoplates starts being incorporated into the Cu1.94S crystal structure at a temperature of around 220 °C, and form pure orthorhombic Cu4SnS4 nanoplates at 260 °C. As the orthorhombic structure of Cu4SnS4 is metastable, it undergoes a phase transformation to the more stable Cu2SnS3 phase at a higher reaction temperature of 270 °C. Furthermore, the size and thickness of Cu4SnS4 nanoplates can be well tuned by the amount of Sn content in the initial reaction mixture to form Cu1.94S nanoplates. Additionally, the formation of Cu1.94S nanoplates is essential for the formation of pure Cu4SnS4 nanocrystals at a fixed reaction temperature. UV-vis and Mott–Schottky analysis show that the as-prepared orthorhombic Cu4SnS4 nanoplates exhibit n-type semiconducting behavior with a band gap of about 1.65 eV. The valence and conduction band potentials have also been determined via theoretical calculations. We believe that our synthetic method and findings will be attractive for the synthesis of other copper-based chalcogenide nanoplates as well as their potential catalytic applications.
研究领域:
材料科学
·
化学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Advanced Science
·
2018
·Vol. 5
·期 6
·1800080
·
IF 12.441
Peng Ge,Hongshuai Hou,Xiaoyu Cao,Sijie Li,Ganggang Zhao,Tianxiao Guo,Chao Wang,Xiaobo Ji
Different dimensions of carbon materials with various features have captured numerous interests due to their applications on the tremendous fields. Restricted by the raw materials and devices, the controlling of their morphology is a major challenge. Utilizing the catalytic features of the intermediates from the low-cost salts and polymerization of 0D carbon quantum dots (CQDs), 0D CQDs are expected to self-assemble into 1/2/3D carbon structures with the assistance of temperature-induced intermediates (e.g., ZnO, Ni, and Cu) from the salts (ZnCl 2 , NiCl 2 , and CuCl). The formation mechanisms are illustrated as follows: 1) the “orient induction” to evoke “vine style” growth mechanism of ZnO; 2) the “dissolution–precipitation” of Ni; and 3) the “surface adsorption self-limited” of Cu. Subsequently, the degree of graphitization, interlayer distance, and special surface area are investigated in detail. 1D structure from 700 °C as anode displays a high Na-storage capacity of 301.2 mAh g −1 at 0.1 A g −1 after 200 cycles and 107 mAh g −1 at 5.0 A g −1 after 5000 cycles. Quantitative kinetics analysis confirms the fundamentals of the enhanced rate capacity and the potential region of Na-insertion/extraction. This elaborate work opens up an avenue toward the design of carbon with multidimensions and in-depth understanding of their sodium-storage features.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Turong Shi,Jiachun Feng,Beibei Tang
Amphiphilic block copolymers are widely used as additives in ultrafiltration membranes preparation by nonsolvent-induced phase separation. During membrane-forming process, an increase in coagulation bath temperature (CBT) will accelerate the kinetics of phase inversion and also promote the micellization of amphiphilic block copolymers. Herein, polyethylene oxide-polypropylene oxide-polyethylene oxide, marketed as Pluronic, is utilized as an additive for preparing asymmetric ultrafiltration membranes. Influence of temperature-induced micelle transition behavior of Pluronic on membrane formation and performance is investigated in detail. It is found that when the CBT increases, temperature-induced micelle transition of Pluronic will lead to a dual effect: (1) The decrease in Pluronic diffusion rate results in a reduced diffusion of the solvent interacting with it, thereby slowing down the precipitation kinetics during phase inversion. (2) The decrease in particle size of Pluronic micelles brings about a reduction in the region left by Pluronic micelles extracted from the casting solution, thus decreasing the membrane pore size. The intrinsic characters of Pluronic, including molecular weight, hydrophilic and hydrophobic block ratio and concentration, determine the dual effect of micelle transition. This work provides an in-depth understanding and practical guidance for the preparation of asymmetric membranes with amphiphilic block copolymers as additive systems.
研究领域:
材料科学
·
膜技术
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 13
·4918
·
IF 4.6
Kaixuan Yang,Naimeng Chen,Xiaomiao Guo,Ruoqi Zhang,Xiaoyu Sheng,Hui Ge,Zhiguo Zhu,Hengquan Yang,Hongying Lü
The search for non-noble metal catalysts for chemical transformations is of paramount importance. In this study, an efficient non-noble metal catalyst for hydrogenation, hexagonal close-packed cobalt (HCP-Co), was synthesized through a simple one-step reduction of β-Co(OH)2nanosheets via a temperature-induced phase transition. The obtained HCP-Co exhibited several-times-higher catalytic efficiency than its face-centered cubic cobalt (FCC-Co) counterpart in the hydrogenation of the C=C/C=O group, especially for the 5-hydroxymethylfurfural (HMF) hydrogenation (8.5-fold enhancement). Density functional theory calculations demonstrated that HMF molecules were adsorbed more firmly on the (112_0) facet of HCP-Co than that on the (111) facet of FCC-Co, favoring the activation of the C=O group in the HMF molecule. The stronger adsorption on the (112_0) facet of HCP-Co also led to lower activation energy than that on the (111) facet of FCC-Co, thereby resulting in high activity and selectivity. Moreover, HCP-Co exhibited outstanding catalytic stability during the hydrogenation of HMF. These results highlight the possibility of fabricating hydrogenation catalysts with satisfactory catalytic properties by precisely tuning their active crystal phase.Keywords:phase-controlled;temperature-induced phase transition;HCP-Co;FCC-Co;hydrogenation
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Yutong Wang,Sha Jiang,Jialiang Xie,Linlin Xie,Chuanliang Feng,Yongjie Wang,Guotao Xiang,Li Li,Yanhao Huang,Xianju Zhou,Feng Wang
Ratiometric luminescent thermometry is favored for its unique advantages and significant potential applications, particularly in the biomedical field. That has driven growing interest in the development of novel luminescent materials with ultra-high sensitivity in the physiological temperature range. Our study focuses on materials that exhibit temperature-induced phase transition within the physiological temperature range, thus facilitating the development of highly sensitive luminescent thermometers. Through a series of experimental explorations, we have discovered that LiYO 2 :1%Sm 3+ undergoes a phase transition from a monoclinic structure to a tetragonal structure within the temperature range of 320–330 K. Subsequently, a luminescent thermometer based on LiYO 2 :Sm 3+ phosphor was designed, capitalizing on the contrasting thermal response of the emissions associated with monoclinic and tetragonal structures, achieving ultra-high sensitivity of 17.51% K −1 at 322 K, making it suitable for the application in the biomedical field. Especially, the optimal temperature range for LiYO 2 : Sm 3+ thermometer aligns well with mitochondrial temperature, presenting potential applications in cancer diagnosis and photothermal therapy.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2015
·Vol. 33
·期 12
·1338-1346
·
IF 1.578
Yupeng Wu,Yangchun Tao,Kuan Cai,Siwei Liu,Yi Zhang,Zhenguo Chi,Jiarui Xu,Yen Wei
Two triblock polymers, tetraaniline- block -poly( N -isopropyl acrylamide)- block -poly(hydroxyethyl acrylate) (TA- b -PNIPAM- b -PHEA) and TA- b -PHEA- b -PNIPAM, were synthesized with unambiguous structure by a two step method. The difference of these two diblock polymers is the connection order of carboxyl group to block, e.g ., carboxyl group to PNIPAM block for PNIPAM- b -PHEA and to PHEA block for PHEA- b -PNIPAM. Secondly, block tetraaniline was linked to the diblock polymer through amidation to yield the corresponding triblock copolymer. Both of them have almost the identical chemical compositions. The only difference is the connection order of each block in the triblock polymers. When they were self-assembled at 45°C in a suitable solution, both of their aggregates have spherical shape with slight defects on their surface with the average diameter of about 400 nm. However, when their aggregate dispersion was cooled down to 20°C, only TA- b -PHEA- b -PNIPAM's morphology changed, forming worm-like aggregates with the diameter of about 100–200 nm transformed from spherical aggregates. Both amphiphilic property and position of each block in this triblock copolymer are very essential for this morphology transformation. Since the worm-like aggregates presented here by our group have hollow structure inside, its controlled release properties for doxorubicin were evaluated. Drug release experiment indicated that along with the temperature changes, the rearrangement of the intermediate layer structure caused morphology change in aggregate, thus accelerating the speed of drug release.
研究领域:
材料科学
·
生物医学工程
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2017
·Vol. 10
·期 5
·1166-1172
·
IF 4.803
Lan-Lan Lou,Huaxin Qu,Wenjun Yu,Bei Wang,Lezi Ouyang,Shuangxi Liu,Wuzong Zhou
Graphical Thermoresponsive lipase catalyst : A UCST-type thermoresponsive polymer–lipase conjugate was exploited and applied as an asymmetric biocatalyst in the kinetic resolution of racemic α-methylbenzyl butyrate, exhibiting high catalytic performance, easy recovery, and good durability. A thermoresponsive lipase catalyst with an upper critical solution temperature (UCST) of about 26 °C was exploited by covalent immobilization of an enzyme, Pseudomonas cepacia lipase (PSL), onto poly(acrylamide- co -acrylonitrile) by glutaraldehyde coupling. The experimental conditions for the PSL immobilization were optimized. The immobilized PSL was much more stable for wide ranges of temperature and pH than free PSL. The material was also evaluated as an asymmetric catalyst in the kinetic resolution of racemic α-methylbenzyl butyrate at 55 °C in an aqueous medium and exhibited high catalytic performance and stability. Up to 50 % conversion and 99.5 % product enantiomeric excess were achieved, thus providing highly pure enantiomers. This biocatalyst could be easily recovered by simple decantation for reuse based on temperature-induced precipitation. It showed good reusability and retained 80.5 % of its original activity with a well reserved enantioselectivity in the 6th cycle. This work would shed light on the future development of new UCST-type enzyme catalysts.
研究领域:
生物化学
·
酶工程
·
材料科学
✓ 已验证
DOI
高影响因子
Soft Matter
·
2015
·Vol. 11
·期 26
·5253-5264
·
IF 4.029
Ge Wang,Peiyi Wu
The temperature-induced phase transition behaviors of a thermoresponsive ionic liquid (tributylhexylphosphonium 3-sulfopropylmethacrylate, [P4,4,4,6][MC3S]) and its polymer (poly-tributylhexylphosphonium 3-sulfopropylmethacrylate, P[P4,4,4,6][MC3S]) have been investigated using DSC, optical microscopy, temperature-variable 1H NMR, and FT-IR in combination with two-dimensional analysis methods, including perturbation correlation moving window (PCMW) and two-dimensional correlation spectroscopy (2Dcos). We found that there exists a distribution gradient of water molecules in P[P4,4,4,6][MC3S] ranging from hydrophobic backbones to hydrophilic sulfonates. Linked together by covalent bonds, P[P4,4,4,6][MC3S] would form an “urchin-like” structure, which can improve its stability and strengthen the gradient distribution of water. Finally, 2Dcos was employed to elucidate the sequential order of chemical group motions during heating. It is concluded that both [P4,4,4,6][MC3S] and P[P4,4,4,6][MC3S] experience the anionic dominated phase transition process. Moreover, the driving force for the phase transitions is shown to be the dehydration of hydrophobic ester carbonyls.
研究领域:
物理化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2017
·Vol. 19
·期 9
·6626-6635
·
IF 4.123
Yuanyuan Zhou,Hui Tang,Peiyi Wu
Temperature-induced phase transition together with the liquid–liquid phase separation (LLPS) phenomenon of poly(oligo(2-isopropyl-2-oxazoline)methacrylate) with the comb-shaped architecture (comb-PiPOx) in aqueous solution has been discussed at the molecular level. Differing from linear poly(2-isopropyl-2-oxazoline) (linear-PiPOx), polymer-rich liquid droplets appear at higher temperature compared with the phase transition determined by differential scanning calorimetry (DSC) in comb-PiPOx solution. As investigated using variable-temperature Fourier transform infrared (FTIR) spectra analysis, the densely grafted architecture gives rise to an intra-molecular interaction (hydrophobic interaction of alkyl groups and H-bond of carbonyl groups) dominating the dehydration process of comb-PiPOx. With temperature increment, most of the water within hydrated polymers is expelled to the outer water phase through intra-molecular association, corresponding to the transition temperature. Afterwards, the dehydration of methyl groups on side chain ends reflects the massive aggregation of polymer chains through inter-molecular association, accompanied by hysteretic LLPS.
研究领域:
高分子化学
·
物理化学
✓ 已验证
DOI
PubMed
高影响因子
MACROMOLECULES
·
2017
·
IF 5.835
Xiao Wang,Jiamin Zhou,Xiaoqing Lv,Baohua Zhang,Zesheng An
Aqueous dispersion polymerization of diacetone acrylamide (DAAM) by chain extension from a hydrophilic poly(N,N-dimethylacrylamide) (PDMA30) macromolecular chain transfer agent (macro-CTA) to produce PDMA30–PDAAMx block copolymer nano-objects was investigated in detail by systematically varying solids content and degree of polymerization of the core-forming PDAAM, leading to the formation of pure lamellae, mixed lamellae/vesicles, and pure vesicles as revealed by dynamic light scattering (DLS), transmission electron microscopy (TEM), atomic force microscopy (AFM), and scanning electron microscopy (SEM). PDMA30–PDAAMx lamellae were found to span an unprecedented wide space in the morphology phase diagram. Moreover, in situ cross-linking of lamellae via statistical copolymerization of DAAM with an asymmetric cross-linker allyl acrylamide and the effect of cross-linking density on the colloidal and morphological stabilities were studied, representing the first report on in situ cross-linking of lamellae during polymerization-induced self-assembly (PISA). Finally, reversible, temperature-induced morphological transitions from lamellae to worms/spheres on cooling were investigated by DLS, TEM, 1H NMR spectroscopy, and rheology. The kinetics of the temperature-dependent morphological transitions and the rheological properties could be tuned by the cross-linking density.
研究领域:
高分子化学
·
材料科学
·
胶体与界面化学
✓ 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）