نتایج جستجو برای: surface properties

تعداد نتایج: 1428668  

2015
Minmin Li Guangyan Qing Yuting Xiong Yuekun Lai Taolei Sun

Life systems have evolved to utilize weak noncovalent interactions, particularly CH-π interaction, to achieve various biofunctions, for example cellular communication, immune response, and protein folding. However, for artificial materials, it remains a great challenge to recognize such weak interaction, further transform it into tunable macroscopic properties and realize special functions. Her...

Journal: :علوم و تکنولوژی پلیمر 0
مهرزاد مرتضایی محمدحسین نویدفامیلی مهرداد کوکبی

the preparation and characterization of the vinyltriethoxysilane-modified silica nanoparticles were investigated. also the surface tension of polystyrene, native (hydrophilic) silica and silane-modified (hydrophobic) silica were determined. two kinds of polystyrene/silica (treated and non-treated) nanocomposites were prepared with different filler loadings by solution method. their viscoelastic...

Journal: :int. j. lignocellulosic products 2014
r. gorgij a. tarmian a. n. karimi

in this study, the effect of soluble chitosan, thyme oil and linseed oil on the mold resistance of wood and its surface properties was investigated. both low and medium molecular weight chitosan with concentration of 1 and 2% were used. cypress wood samples with dimensions of 20 × 20 × 70 mm and moisture content of 12% were saturated by the preservatives. the results showed that the maximum abs...

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشگاه دانشهای بنیادی (مرکز تحقیقات فیزیک نظری و - پژوهشکده علوم نانو 1392

among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی اصفهان - دانشکده شیمی 1389

in this thesis, a new optically active poly(amide-imide) (pai) was synthesized by the indirect polycondensation reaction of the l-phenylalanine based diacid chloride and 4,4?-diaminodiphenylether in the presence of triethylamine in n-methyl-2-pyrrolidone. the formation of pai was confirmed by ftir, 1h nmr and elemental analysis. in next step, the surface of titanium dioxide (tio2) nanoparticles...

Journal: :علوم و تکنولوژی پلیمر 0
محمدرضا عرب بافرانی تهران، دانشگاه تربیت مدرس، دانشکده مهندسی شیمی، بخش مهندسی پلیمر، صندوق پستی 114-14115 مهدی رزاقی کاشانی تهران، دانشگاه تربیت مدرس، دانشکده مهندسی شیمی، بخش مهندسی پلیمر، صندوق پستی 114-14115

one of the most important factors that affect tire friction is surface roughness, which determines the size of the real contact area, real pressure distribution on the contact interface, and scales of mechanical engagement between viscoelastic rubber and a rough substrate. the need to predict coefficient of friction (cof) for rubber on rough surfaces for applications such as traction of tires o...

Journal: :علوم و تکنولوژی پلیمر 0
مهدی رزاقی کاشانی رسول اسمعیلی نیسیانی

coeffcient of  friction  (cof)  for  rubber parts  is one of  the key parameters in their interaction with solid rough surfaces (micrometer to millimeter scales),  such  as  tire-road  interactions. cof  of  rubber  depends  on  viscoelastic properties of rubber, roughness characteristics of the counter-part surface, and process variables such as contact nominal pressure and sliding speed. due ...

Journal: :journal of applied and computational mechanics 2015
morteza karimi mohammad hossein shokrani ali reza shahidi

in this article, finite difference method (fdm) is used to study the size-dependent free vibration characteristics of rectangular nanoplates considering the surface stress effects. to include the surface effects in the equations, gurtin-murdoch continuum elasticity approach has been employed. the effects of surface properties including the surface elasticity, surface residual stress and surface...

Journal: :علوم و تکنولوژی پلیمر 0
الهه مسایلی صدیقه برهانی

low temperature plasma technology is well established in surface modification of polymer materials on industrial scale. this method modifies surface properties of polymers without chemicals, manual work and reducing chemicals and energy consumption. in this study, low pressure plasma treatment was used to develop hydrophilic properties of polyethylene terephthalate (pet) fabrics. it was found t...

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