今天是:
CCMS
搜索:
新闻动态
 
 
 
友情连接
华中科技大学 电子科学与技术系
白云黄鹤 启明学院
通知公告
FERROMAGNETIC MICROWIRES ENABLED MULTIFUNCTIONAL POLYMER COMPOSITES
发布日期:2011-1-11 0:00:00     作者:admin

FERROMAGNETIC MICROWIRES ENABLED MULTIFUNCTIONAL POLYMER COMPOSITES

Faxiang Qin
Advanced Composite Center for Innovation and Science, Department of Aerospace Engineering, University of Bristol, University Walk, Bristol, BS8 1TR, UK

Multi-functional composite essentially refers to a composite material that, beyond the primary structural function, possesses other functionalities as well achieved by constituent materials in an optimized structure [1,2]. Therefore, two aspects are highlighted in this definition: (i) the composite must have multiple functions, and (ii) the additional functions are enabled by the constitutive elements in the material. Such a concept has led us to target the efforts into exploring ideal functional fillers that could meet the criteria: (i) a likely omnipotent functional filler that will ensure the achievement of multi-functionalities and a relatively simple composite architecture, and (ii) preferred fine geometry and large susceptibility to external fields to warrant a low and effective loading of fillers that enables a homogeneous material in favor of structural integrity and implementation. In this context, microwires embedded in a polymeric matrix can meet the above criteria.
Soft ferromagnetic amorphous glass-coated microwires (AGCMs) with singular giant magneto-impedance (GMI) and/or giant stress-impedance (GSI) effect are excellent candidate materials for making highly sensitive magnetic and stress sensors [3].Since AGCMs possess their small dimension (1-30 μm in diameter), reasonable electrical conductivity (~6×103 S/cm), high magnetic permeability (~104), and high mechanical strength (~103 MPa), they can be incorporated into polymer-based composites to produce a variety of indiscriminate functionalities but minimum physical perturbations to the matrix.
In this talk, we report a thorough study of the properties of the composites containing soft ferromagnetic amorphous glass-coated microwires embedded in a polymer matrix. We show that the mechanical properties retain in the resultant wire composites. Optimized GMI/GSI effect is occasioned by the composite architecture such as wire amounts, composite layer and annealing treatments. Negative effective permittivity is extracted from measured S-parameters in free-space and can be well tuned by the applied field in terms of its magnitude and sign. Exceptional EMI shielding effectiveness of 18dB is shown at 1-2GHz. All these functionalities are achieved with a very low filler loading of ~10-4, thereby making the microwire polymer composite a truly multifunctional composite material for a variety of technological applications.

References
[1] S. Torquato, S. Hyun, and A. Donev, Physical Review Letters, 89(2002): 266601.
[2] J.P. Thomas and M.A. Qidwai, Acta Materialia, 52(2004): 2155-2164.
[3] M.H. Phan, H.X. Peng, 53(2008): 323--420.

Brief Biography:

Dr. Faxiang Qin is a post-doctoral researcher in Advanced Composite Centre for Innovation and Science at the University of Bristol. He received the Master of Science in materials processing from the South China University of Technology in 2007 and Ph.D in composites materials from the University of Bristol in 2010. He was a recipient of the Overseas Research Students Awards Scheme (ORSAS) and the University of Bristol Postgraduate Student Scholarship. He was nominated for the Exceptional Thesis Prize and selected as one of the two candidates at Bristol for UK Royal Academy Engineering Fellowship. His research interest lies in nano films, multifunctional composites, smart materials and applied physics. 

秦发祥博士简历

返回首页  |   关于我们  |   联系我们  |   免责声明
华中科技大学CCMS中心
地址:湖北武汉华中科技大学启明学院A座8楼     联系电话:027-87544472     鄂ICP015745822号    
版权归华中科技大学CCMS中心,信息未经允许不得转载     技术支持:金昌利科技