Institute of Polymer Materials
Institute of Polymer Materials
Zhu L.,Institute of Polymer Materials |
You L.,Institute of Polymer Materials |
Shi Z.,Institute of Polymer Materials |
Song H.,Institute of Polymer Materials |
Li S.,Institute of Polymer Materials
Journal of Applied Polymer Science | Year: 2017
This article presented a novel application for the graphitic carbon nitride (g-C3N4), which was used as nanofillers to improve the tribological properties of polyimide (PI). The composite based on PI and g-C3N4 was prepared by mechanical mixing process and hot compression molding process. The characterizations of g-C3N4 and PI/g-C3N4 composites were investigated by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. Friction and wear tests were carried out using UMT-2 reciprocating tribo-tester against stainless steel ball under dry friction. The results showed that the amount of g-C3N4 was decisive to the tribological properties of PI/g-C3N4 composites. The optimal tribological properties occurred when the amount of g-C3N4 was 10 wt %, which showed the smallest friction coefficient and the lowest wear rate. Furthermore, this work provided an example of application for the g-C3N4 as the excellent nanofiller in polymer matrix composites. © 2017 Wiley Periodicals, Inc.
Jariyavidyanont K.,Martin Luther University of Halle Wittenberg |
Kuhnert I.,Institute of Polymer Materials |
Focke W.,Applied Materials |
Androsch R.,Martin Luther University of Halle Wittenberg
Polymer Engineering and Science | Year: 2017
The semicrystalline morphology of injection moldings of polyamide 11 (PA 11) prepared using mold temperatures of 25, 50, and 80°C was investigated. Regardless of the mold temperature, position-resolved X-ray diffraction (XRD) and polarized-light optical microscopy (POM) revealed presence of poor/imperfect α-crystals with an almost hexagonal arrangement of molecular stems in a nonspherulitic superstructure in the skin, and formation of α-crystals and spherulites in the core. With increasing mold temperature, the thickness of the skin layer decreased, and the perfection of α-crystals and the spherulite size in the core increased. The experimental observations are discussed in terms of predicted crystallization temperatures, with the prediction based on cooling-rate simulations for the various parts of the injection moldings using Moldflow® and analysis of crystallization of the relaxed melt using fast scanning chip calorimetry, XRD, and POM. It is shown that the structure gradient in PA 11 injection moldings can be forecast without considering the effects of shear for this particular polymer. © 2017 Society of Plastics Engineers.
Koniger T.,Institute of Polymer Materials |
Rechtenwald T.,Bayerisches Laserzentrum GmbH |
Al-Naimi I.,Institute of Polymer Materials |
Frick T.,Bayerisches Laserzentrum GmbH |
And 2 more authors.
Journal of Coatings Technology Research | Year: 2010
A CO 2-laser treatment was used to improve the electrical conductivity of coatings of indium tin oxide (ITO) nanoparticles on flexible polyethyleneterephthalate (PET) substrates. The electrical conductivity and the transparency of CO 2-laser-treated ITO nanoparticle coatings were characterized with regard to the application as transparent electrodes. Furthermore, the stability of the electrical conductivity under oscillatory bending was investigated. A specific resistance of 0.12 Ω cm is obtained by CO 2-laser treatment without thermally damaging the PET film. The improvement of the electrical conductivity can be explained by a slight sinter neck formation. For a film thickness of 3 μm, a sheet resistance of 400 Ω/□ and a transmission in the visible range of 80%were achieved. The stability of the electrical conductivity of CO 2-laser-treated ITO nanoparticle coatings under bending was investigated using a specially constructed device for the application of various oscillatory bending loads. For a bending radius of 10 mm, the sheet resistance does not exceed 1000 Ω/h after 300 bending cycles. Compared to commercial sputtered ITO coatings, CO 2-laser-treated ITO nanoparticle coatings show a significant higher stability under oscillatory bending. © FSCT and OCCA 2009.
News Article | October 25, 2016
Home > Press > KaSAM-2016: International Conference on Material Sciences has successfully concluded in Pokhara of Western Nepal Abstract: The Kathmandu Symposia on Advanced Materials- 2016 (KaSAM-2016), organized by Nepal Polymer Institute (NPI) in association with the Nepal Academy of Science and Technology (NAST), the Pokhara University and German-based Institute of Polymer Materials (IPW) has successfully concluded in Pokhara of western Nepal. Vice-Chancellor of Nepal Academy of Science and Technology (NAST) Prof. Dr. Jiba Raj Pokharel inaugurated the meeting by lighting Panas-Batti in the evening of October 17 at Mount Kailash Resort (Lakeside, Pokhara) in front of more than 180 scientists from 16 countries across the globe. During his inauguration speech, Prof. Pokharel emphasized the importance of investment in scientific researches and activities in the country and praised the organizing committee for conducting such an international meeting outside of the capital city. Another speaker Vice-Chancellor of Pokhara University Prof. Dr. Chiranjibi Sharma, patron of KaSAM-2016, expressed his happiness to be the co-organizer of this mega scientific event in Pokhara and highlighted the global platform provided by this program for the students and professors of the university. The inauguration ceremony was chaired by the President of Nepal Polymer Institute Prof. Dr. Rameshwar Adhikari (Central Department of Chemistry, Tribhuvan University, Kathmandu) who is also the Convener of the event. During the ceremony, conducted by Ms. Jyoti Giri (treasurer of NPI), Dr. Rajesh Pandit (Vice-President of NPI) gave a vote of thanks to all the contributors on behalf of the organizing committee. In the daytime of October 17, a special workshop for students and young scientists was also organized in Pokhara University. This short course named as Kathmandu Autumn School on Chemistry and Chemical Technologies (KASChem)-2016 was focused on nanomaterials where scientists from Czech Republic, France, Germany, Japan and Nepal gave tutorial lectures on various aspects of synthesis, characterization and application of nanomaterials. Interestingly, KASChem-2016 was organized under the banner of NEPAS (No-border Educational Program Applied to Science), a new initiative of Nepal Polymer Institute to promote educational outreach program throughout the country. A special lecture was also held on Oct 17 on Science, Technology, Engineering and Math (STEM): Changing the World One Bit at a Time by Ms. Gwendolyn Bluemich from Global Foundries, USA. According to Prof. Adhikari, the four-day long conference was focused on in-depth discussions about latest researches on material science and engineering. Among more than 140 papers, interesting researches about the use of nano/bio-materials to tackle some of the ongoing global problems such as human infection caused by antibiotic resistant superbugs were also discussed during the meeting, said Prof. Adhikari. Special sessions on Science, Technology & Innovations and Natural Products and Pharmaceuticals for Nepal were also part of the meeting. KaSAM2016 participants were from Bangladesh, China, Czech Republic, France, Germany, India, Italy, Japan, Korea, Nepal, Pakistan, Poland, Singapore, South Africa, Sweden and the United States of America. In a closing ceremony, held in the afternoon of October 20, Ex-Vice Chancellor of the Pokhara University Prof. Dr. Bishnu Raj Tiwari gave his concluding remarks. During the ceremony, German scientist Prof. Dr. Michael Hess- former secretary of Polymer Division of the International Union of Pure and Applied Chemistry (IUPAC), French Scientist Prof. Dr. Jean Marc Saiter, Dr. Ralf Lach of Germany and Prof. Dr. Paras Nath Yadav of Tribbuvan University, Nepal also shared their valuable experiences and praised the efforts of the organizing committee for organizing a highly successful KaSAM-2016. Many students and participants commented the program being a historically successful event. Conference Convener Prof. Rameshwar Adhikari, who also conducted the closing ceremony, started his speech by appreciating the works of the organizing committee members and thanked to all the co-organizers (Pokhara University, NAST and IPW Germany), guests, advisors, speakers, presenters, participants, journalists, sponsors and those who directly or indirectly helped to make the event a successful one. Prof. Adhikari also emphasized the importance of organizing KaSAM-2016 in Pokhara not only to promote researches at the regional level amid very limited scientific activities outside of Kathmandu, but also to provide a global platform for direct interactions and networking of local scientists among the international experts. During his closing remarks, Prof. Adhikari further highlighted the responsibilities of younger generation for popularization of science and urgent necessity of investment and dedication in science and technology for the development of the country. He also presented an outline of the upcoming programs of NPI including Nepal Chemical Congress-2017, 2nd Young Scientist Summit-2017, and continuation of KASChem-2016 Outreach program, under the framework of NEPAS, in Chitwan (October 22) and Biratnagar (October 24) with active involvement of foreign scientists. An evaluation committee of professors led by Dr. Netra Lal Bhandari (founding Secretary of the Nepal Polymer Institute) was also formed to monitor and evaluate the scientific quality and significance of the researches presented during the program. Prof. Dr. Motee Lal Sharma, organizing member, announced the name of the awardees while Convener of the event Prof. Adhikari and Ex-Vice Chancellor of Pokhara University Prof. Tiwari distributed certificates to the winners. The following three presenters received the KaSAM2016 Best Poster Awards for their works: · Ms. Ferdousi Begum (Bangladesh): Sodium dodecyl sulfate/1-butanol/cyclohexane/water microemulsions: Percolation phenomena and microstructural phase transition · Azad Kumar (India): Kinetics study of photocatalytic degradation of tartaric acid in UV-Visible light at various parameters by the Cobalt Nickel doped Titania (Co0.05:Ni0.10:TiO2) · Dr. Rafal Poreba (Czech Republic): Hydrolytic stability of polyurethanes tested in physiologically simulated conditions Three Nepalese students were also awarded for their works in different scientific disciplines: Prameela Khadka (Kathmandu), Arun Acharya (Kathmandu) and Ram Milan Rana (Pokhara). All three Nepalese student awardees will receive a complementary registration to the 2nd Young Scientists Summit-2017 organized by NPI in Kathmandu during the upcoming winter. The works of the KaSAM-2016 Secretariat led by women scientists of NPI Dr. Sharmila Pradhan, Shanta Bhattarai and Prasamsha Pant was praiseworthy. Local accommodations and travel were nicely arranged by members of the organizing committee including Kedar Nath Dhakal, Dhruba Babu Subedi, Anil Gautam, Komal Prasad Malla, Bishnu Neupane, Krishna Kumar Raut and Kamal Rai. The KaSAM-2016 was well coordinated to the Nepalese media by Prof. Dr. Motee Lal Sharma (Tribhuvan University, Kathmandu) and the international communities by Santosh Thapa (PhD Fellow at the University of North Texas Health Science Center in USA). For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
Khimenko L.L.,Institute of Polymer Materials |
Rybakov A.P.,Polytechnic University of Mozambique |
Rybakov N.A.,Polytechnic University of Mozambique |
Kozlovc A.N.,Perm State Agricultural Academy
Journal of Applied Mechanics and Technical Physics | Year: 2014
Results of experimental measurements of Young’s modulus, burning rate, and specific heat of condensed high-energy polymer compositions (solid propellants) subjected to microwave radiation are reported. Experimental equipment and arrangement of experiments are described; the results obtained are analyzed. © Pleiades Publishing, Ltd., 2014.
Kristofic M.,Institute of Polymer Materials |
Ujhelyiova A.,Institute of Polymer Materials
Fibres and Textiles in Eastern Europe | Year: 2012
Blending polymers is widely used for the preparation of new materials. The disadvantage of this application is that the polymer components are usually not compatible and the preparation of blends with suitable (mainly processing and mechanical) properties is not satisfactory. The use of a third compound, called a compatibiliser, is an effective way to ameliorate the end-use properties of the blend. Compatibilisers based on grafted or block copolymers are often used. The present contribution deals with the compatibilisation of polypropylene/polyamide blends with compatibilisers based on grafted or block polyolefines.
Kristofic M.,Institute of Polymer Materials |
Ujhelyiova A.,Institute of Polymer Materials |
Ryba J.,Institute of Polymer Materials
Fibres and Textiles in Eastern Europe | Year: 2012
In this contribution blend metallocene polypropylene (mPP) fibres modified with 4, 8, 12 wt.% of copolyamide A and 4, 8, 12 wt.% of compatibiliser L were prepared. Copolyamide A consists of 85 wt.% of ε-caprolactam and 15 wt.% of nylon salt of adipic acid and diethylenetriamine. Compatibiliser L is low molecular isotactic polypropylene grafted with maleineanhydride. Thermal properties of the components, blends and modified mPP fibres were evaluated. Fibres modified with both copolyamide A and compatibilizer were successfully spun and drawn, with the opposite being the case for mPP fibres modified only with copolyamide A without compatibiliser L, which were not spun, confirming the positive role of compatibiliser L. The modified fibres conserve their thermal characteristics-melting temperature, melting enthalpy and entropy in the whole interval of both additive concentrations evaluated. The positive influence of the compatibiliser was found from the point of melting enthalpy and melting entropy.
Dietrich H.,Theoretical Chemistry and Computer Chemistry Center |
Scheiner S.,Institute of Polymer Materials |
Portilla L.,Institute of Polymer Materials |
Zahn D.,Theoretical Chemistry and Computer Chemistry Center |
Halik M.,Institute of Polymer Materials
Advanced Materials | Year: 2015
Tuning the electrostatics of ethylene-glycol-based self-assembled monolayers (SAMs) by doping with ions is shown. Molecular dynamics simulations unravel binding mechanisms and predict dipole strengths of the doped layers. Additionally, by applying such layers as dielectrics in organic thin-film transistors, the incorporated ions are proven to enhance device performance by lowering the threshold voltage and increasing conductivity. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Nooeaid P.,Friedrich - Alexander - University, Erlangen - Nuremberg |
Roether J.A.,Friedrich - Alexander - University, Erlangen - Nuremberg |
Roether J.A.,Institute of Polymer Materials |
Weber E.,Friedrich - Alexander - University, Erlangen - Nuremberg |
And 3 more authors.
Advanced Engineering Materials | Year: 2014
Multilayered scaffolds that provide tailored space-specific biological and mechanical functions are promising for interface tissue engineering such as in osteochondral tissue regeneration. In this study, fabrication techniques, including foam replication, gelation, and freeze-drying techniques, were combined in order to manufacture stratified scaffolds mimicking the layered structure of native osteochondral tissue. 45S5 Bioglass® and alginate were used to fabricate 3D highly porous (composite) scaffolds for the underlying subchondral bone layer. Freeze-dried alginate-based scaffolds were produced for the cartilage layer. Finally, both layers were integrated using a novel alginate/45S5 Bioglass® hybrid interface acting as an adhesive, which functions as the cartilage-bone interfacial layer. Novel multilayered scaffolds were optimized to achieve the complex requirements for osteochondral tissue engineering such as the 3D architecture, porous structure, physical, and mechanical properties, which are presented and discussed in the context of the intended application of the novel scaffolds in osteochondral tissue regeneration. Multilayered scaffolds based on alginate freeze-dried foam and alginate coated Bioglass®-based foam are developed as a promising candidate for osteochondral (cartilage-subchondral bone) tissue engineering. Two distinct phases are integrated by the application of alginate/Bioglass® hybrid adhesive, which maintained interfacial stability. Alginate foams provide high porosity, good interconnectivity, high water absorption, and sufficient mechanical properties. In addition, alginate coated Bioglass®-based scaffolds exhibit the basic features required for bone regeneration. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
PubMed | Theoretical Chemistry and Computer Chemistry Center and Institute of Polymer Materials
Type: Journal Article | Journal: Advanced materials (Deerfield Beach, Fla.) | Year: 2016
Tuning the electrostatics of ethylene-glycol-based self-assembled monolayers (SAMs) by doping with ions is shown. Molecular dynamics simulations unravel binding mechanisms and predict dipole strengths of the doped layers. Additionally, by applying such layers as dielectrics in organic thin-film transistors, the incorporated ions are proven to enhance device performance by lowering the threshold voltage and increasing conductivity.