The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform
Yonghui Zhou - One of the best experts on this subject based on the ideXlab platform.
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investigation of bulk and in situ mechanical properties of coupling agents treated wood plastic composites
Polymer Testing, 2017Co-Authors: Yonghui ZhouAbstract:Abstract This paper presents the interfacial optimisation and characterisation of WPC by the use of maleated and silane coupling agents (MAPE, Si69 and VTMS), and its effect on the bulk and in situ mechanical properties. The results showed the treated WPC possessed better interface by showing improved compatibility between the constituents, wettability of wood flour, and resin penetration in the SEM images. The enhanced interface led to the increase in the tensile strength and stiffness of the treated WPC, which was confirmed by their superior load bearing capacity, namely the higher storage moduli measured by DMA. The observed shift of the relaxation peak of the treated WPC indicated the constraints on the segmental mobility of the polymeric molecules resulted from the treatments. Nanoindentation investigation revealed that the in situ mechanical properties were subject to a number of phenomena including fibre weakening or softening impact, crystalline structure transformation and cell wall deformation, concluding that the bulk mechanical properties of WPC might not be governed by the local Property of Materials within the interface.
Guoqing Wang - One of the best experts on this subject based on the ideXlab platform.
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heparinized plla plcl nanofibrous scaffold for potential engineering of small diameter blood vessel tunable elasticity and anticoagulation Property
Journal of Biomedical Materials Research Part A, 2015Co-Authors: Weizhong Wang, Wei Nie, Wei Feng, Kexin Qiu, Xiaojun Zhou, Yu Gao, Guoqing WangAbstract:The success of tissue engineered vascular grafts depends greatly on the synthetic tubular scaffold, which can mimic the architecture, mechanical, and anticoagulation properties of native blood vessels. In this study, small-diameter tubular scaffolds were fabricated with different weight ratios of poly(l-lactic acid) (PLLA) and poly(l-lactide-co-ɛ-caprolactone) (PLCL) by means of thermally induced phase separation technique. To improve the anticoagulation Property of Materials, heparin was covalently linked to the tubular scaffolds by N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide coupling chemistry. The as-prepared PLLA/PLCL scaffolds retained microporous nanofibrous structure as observed in the neat PLLA scaffolds, and their structural and mechanical properties can be fine-tuned by changing the ratio of two components. The scaffold containing 60% PLCL content was found to be the most promising scaffold for engineering small-diameter blood vessel in terms of elastic properties and structural integrity. The heparinized scaffolds showed higher hydrophilicity, lower protein adsorption ability, and better in vitro anticoagulation Property than their untreated counterparts. Pig iliac endothelial cells seeded on the heparinized scaffold showed good cellular attachment, spreading, proliferation, and phenotypic maintenance. Furthermore, the heparinized scaffolds exhibited neovascularization after subcutaneous implantation into the New Zealand white rabbits for 1 and 2 months. Taken together, the heparinized PLLA/PLCL nanofibrous scaffolds have the great potential for vascular tissue engineering application. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 1784–1797, 2015.
P Paufler - One of the best experts on this subject based on the ideXlab platform.
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micro and nanoindentation techniques for mechanical characterisation of Materials
International Materials Reviews, 2006Co-Authors: N K Mukhopadhyay, P PauflerAbstract:AbstractIndentation techniques have been extensively used for mechanical characterisation of Materials. Development of instrumented indentation techniques at low and ultra low load levels has further improved their utility for understanding the mechanical responses of solids at micro and nano scales. The variation of hardness with the load/depth of indentation, known as indentation size effect, has led to difficulties in using hardness as a fundamental or characteristic mechanical Property of Materials. Detailed discussions are focused on the issue of indentation size effect in brittle and ductile solids. Various theoretical models accounting for the indentation mechanics are highlighted. The results obtained from these techniques with quasicrystals, bulk metallic glasses and nanoMaterials are reviewed. The issues related to phase transformation during indentation tests are briefly discussed. The industrial use of the indentation technique has been pointed out. Some of the current issues and directions fo...
T. Yao - One of the best experts on this subject based on the ideXlab platform.
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a probe of intrinsic valence band electronic structure hard x ray photoemission
Applied Physics Letters, 2004Co-Authors: Yoshikuni Takata, K. Tamasaku, D. Miwa, J. J. Kim, Makina Yabashi, Tekeshi Tokushima, T Ishikawa, S Shin, K Kobayashi, T. YaoAbstract:Hard x-ray valence band photoemission spectroscopy (PES) is realized using high-energy and high-brilliance synchrotron radiation. High-energy (∼6 keV) excitation results in larger probing depths of photoelectrons compared to conventional PES, and enables a study of intrinsic electronic Property of Materials in actual device structures much less influenced by surface condition. With this technique, requirements for surface preparation are greatly reduced, if not eliminated. It is a nondestructive tool to determine electronic structure from surface to genuine bulk as shown by a study on SiO2/Si(100). Electronic structure modification related to the ferromagnetism in the diluted magnetic semiconductor Ga0.96Mn0.04N is also observed.
Yalin Dong - One of the best experts on this subject based on the ideXlab platform.
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controllable hierarchical micro nano patterns on biomaterial surfaces fabricated by ultrasonic nanocrystalline surface modification
Materials & Design, 2018Co-Authors: Yuan Liang, Haifeng Qin, Nitin Mehra, Jiahua Zhu, Zhengnan Yang, Gary L Doll, Yalin DongAbstract:Abstract In this work, we have shown that Ultrasonic Nanocrystal Surface Modification (UNSM) cannot only improve the mechanical properties of Ti-based bioMaterials but also produce surface texture with hierarchical micro/nanoscale patterns due to its high controllability. After UNSM-treatment the surface texture of Ti-based biomaterial consists of a major microscale structure with widths ranging from 4 μm to 200 μm, and an embedded nanoscale structure with widths as small as 120 nm. With a customized cylinder tip, the average surface roughness (Ra) can be reduced to 0.03 μm, comparable to the superfinishing surface. The embedded nanoscale structure originates from the formation of the pile-up, which is determined by the elastic-plastic Property of Materials. Such hierarchical patterns enable new functions for the treated surface. It is demonstrated that light dispersion and the alteration of wettability can be achieved by controlling surface patterns using UNSM. The capacity of improving mechanical properties, biocompatibility, and hydrophobicity simultaneously, in conjunction with its low-cost and easy-to-operate features, makes it a promising surface engineering technique for biomaterial treatment.
