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امروز : چهارشنبه, ۳۰ بهمن , ۱۳۹۸  .::.  اخبار منتشر شده : 3 خبر

In polymer electrolyte fuel cells (PEFCs), protons from the anode are transferred to the cathode through the ionomer membrane. By impregnating the ionomer into the electrodes, proton pathways are extended and high proton transfer efficiency can be achieved. Because the impregnated ionomer mechanically binds the catalysts within the electrode, the ionomer is also called a binder. To yield good electrochemical performance, the binder should be homogeneously dispersed in the electrode and maintain stable interfaces with other catalyst components and the membrane. However, conventional binder materials do not have good dispersion properties. In this study, a facile approach based on using a supercritical fluid is introduced to prepare a homogeneous nanoscale ...

The applicability and service time of polymer details working in various media are limited by the degradation of their physical and mechanical properties. From the structural point of view the weakest places strongly affected by ageing are the surface and boundary regions of the crystallites. If a material is subjected to high-strain deformation, it deforms permanently (plastic deformation) and ultimately fails. For sufficiently low stresses and strains, the polymeric material behaves as a linear elastic solid. The point where the behaviour starts to be non-linear is called the proportional limit. The local maximum in the stress-strain curve is called the yield point and indicates the permanent deformation. The corresponding stress and elongation are called ...

Over the last few years, the chances of creating new conducting polymers with the help of machine learning have caught the attention of many researchers in the field of chemistry. Now, a team of researchers has discovered a new kind of polymer which contains high thermal conductivity and can be beneficial to the 5G mobile communication technologies. Researcher Ryo Yoshida said that many aspects remain to be explored, such as “training” computational systems to work with limited data by adding more suitable descriptors. He added, “ML for polymer or soft material design is a challenging but promising field as these materials have properties that differ from metals and ceramics, and are not yet fully predicted by the existing theories.” This ...

A high-spin ground-state donor-acceptor conjugated polymer
26 مه 2019

PolymPart: Interest in high-spin organic materials is driven by opportunities to enable far-reaching fundamental science and develop technologies that integrate light element spin, magnetic, and quantum functionalities. Although extensively studied, the intrinsic instability of these materials complicates synthesis and precludes an understanding of how fundamental properties associated with the nature of the chemical bond and […]

Creating 3D Printed Polymer Antennas for Synthetic Aperture Radar (SAR) Systems
18 مه 2019

PolymPart: Thesis student Jan Reifenhäuser at the Koblenz University of Applied Sciences explores the uses of 3D printing in creating improved antennas for multiple applications, outlined in ‘Investigation of a Plastic Printed Slotted Waveguide Antenna for Airborne SAR Applications.’ Reifenhäuser’s interest in creating antennae are directly related to a new project at the German Aerospace […]

معرفی انواع پلیمر
16 مه 2019

(مرجع پلیمر بازار ایران) انواع پلیمر : پلیمرها به طور کلی به سه گروه اصلی گرمانرم ها یا تروموپلاستیک ها، گرما سخت ها یا ترموست ها، الاستومرها دسته بندی می‌شوند. ترموپلاستیک ها با افزایش دما نرم شده و با خنک شدن به سختی اولیه اشان برمی گردند و بیشتر قابل ذوب هستند، به عنوان مثال، […]

Lipid–polymer hybrid nanoparticles as a nextgeneration drug delivery platform
19 مارس 2019

PolymPart: Lipid–polymer hybrid nanoparticles (LPHNPs) are next-generation core–shell nanostructures, conceptually derived from both liposome and polymeric nanoparticles (NPs), where a polymer core remains enveloped by a lipid layer. Although they have garnered significant interest, they remain not yet widely exploited or ubiquitous. Recently, a fundamental transformation has occurred in the preparation of LPHNPs, characterized by […]

Aging Characterization of Polymer Powders in Additive Manufacturing
09 مارس 2019

Fine powders and granular materials are extensively used in industrial applications. It is essential to precisely characterize these materials in order to control and optimize processing techniques. The characterization techniques are related to the properties of the grains (morphology, granulometry, chemical composition, etc.) or to the behavior of the bulk powder (density, flowability, electrostatic properties, […]

انتخاب چسب مناسب برای استفاده در محیط های خارجی
04 فوریه 2019

مرجع پلیمر در بازار ایران: انتخاب چسب مناسب برای کاربرد در محیط های خارجی نیاز به توجه به گزینه های بیشتری دارد. چسباندن چیزهایی که در شرایطی متفاوت از فضای داخلی مثل وجود رطوبت، اشعه UV و یا تغییرات دما، قرار دارد چالش های دیگری را برای انتخاب چسب مناسب پیش روی ما قرار می […]

بهینه سازی کامپوزیت چوب پلاستیک با استفاده از الگوریتم ژنتیکی
21 ژانویه 2019

مرجع پلیمر در بازار ایران: کامپوزیت چوب پلاستیک (کامپوزیت چوب پلیمر) یا کامپوزیت های فیبر طبیعی، اساسا شامل ترکیبی از پودر پلاستیک و چوب می باشند. کیفیت محصول معمولا” اندازه گیری شده و کاملا” وابسته به خواص مکانیکی مواد کامپوزیتی است که برای توسعه محصول استفاده می شود و به همین دلیل، آزمایش‌های زیادی در آزمایشگاه‌های کارخانجات برای […]

مقاله اصول طراحی برای استفاده از مواد پلیمری در محیط های کریوژن
08 ژانویه 2019

مرجع پلیمر در بازار ایران: تحقیقات زیادی توسط ناسا و دیگر سازمان های دولتی در دهه های ۱۹۶۰ و ۱۹۷۰ صورت گرفته است تا درک بهتری از کارایی مواد پلیمری در محیط های کریوژن (درجه حرارت کمتر از منفی ۱۵۰ درجه سانتیگراد) حاصل شود. بخش عمده این تحقیق به منظور بهبود آببندی، پمپ ها، دریچه […]

Emerging Chitosan-Based Films for Food Packaging Applications
28 دسامبر 2018

ABSTRACT: Recent years have witnessed great developments in biobased polymer packaging films for the serious environmental problems caused by the petroleum-based nonbiodegradable packaging materials. Chitosan is one of the most abundant biopolymers after cellulose. Chitosan-based materials have been widely applied in various fields for their biological and physical properties of biocompatibility, biodegradability, antimicrobial ability, and easy film forming […]

Porous Carbons from Plastic Waste
25 دسامبر 2018

Abstract: Thermoplastic polymers (such as polypropylene, polyethylene, polyvinyl chloride, polystyrene, etc.) are major constituents of municipal solid waste. Millions of tons of plastic waste are discarded each year, most of which is either incinerated or dumped in landfills. As an alternative, methods using these wastes as feeds for the production of value-added products such as fuels, carbon nanotubes, and […]