Characterization of thermoelectric and thermogravimetric properties of conductive PEDOT:PSS films blended with SWCNTs and PVA

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was blended with polyvinyl alcohol (PVA) and single-walled carbon nanotube (SWCNT) filler to form composites with thermoelectric properties. Studied samples were obtained by drop coating and solution casting methods. Thermoelectric measurements of PEDOT:PSS demonstrated that the addition of 5 wt. % SWCNTs increased the Seebeck coefficient value from 8.0 μV/K to 23.6 μV/K, while in the case of PEDOT:PSS/PVA blended with 5 wt. % SWCNT Seebeck coefficient value of 20.3 μV/K was achieved. Thermogravimetric analysis showed slight SWCNT effect on thermal stability of the investigated systems.

Mechanical properties of injection-molded binary blends of polyethylene with small additions of a liquid-crystalline polymer

The results of the investigation of the mechanical properties of polyethylene (PE) blends with small (<3 wt %) additions of thermotropic liquid-crystalline polymers (LCPs) are reported. PE/LCP compositions with various LCP weight contents were obtained by thermoplastic mixing in a two-stage process. Short-term and long-term mechanical behavior of various PE/LCP compositions were analyzed. Data on the influence of LCP addition on the tensile elastic modulus [or Young's modulus (E)], stress at yield (σY), stress at break (σB), strain at yield, strain at break, and deformation at long-term (1000-h) tensile creep were obtained. The experimental results of the investigation show that even small …

Research of the physical-chemical properties of adhesive radiation-modified thermosetting materials based on polyolefins and their composites

The present paper surveys the investigation results of the adhesive behavior with steel of different polyethylenes (LDPE, HDPE) irradiated with γ-radiation in vacuum, oxygen, and air, using rheological, optical, thermomechanical and other methods. To study the adhesive contact, the technological parameters applicable to thermosetting polymer material were taken into consideration. The results show the suitable methods in order to obtain thermosetting polymer materials with improved adhesive and thermomechanical properties.

Manufacturing, structure and properties of recycled polyethylene terephthalate /liquid crystal polymer/montmorillonite clay nanocomposites

Polyethylene terephthalate (PET)/liquid crystal polymer (LCP)/monthmorillonite clay (MMT) compositions were obtained by melt mixing. Their mechanical, structural, rheological and thermal properties were investigated.

Epoxy composites filled with high surface area-carbon fillers

Citation: J. Appl. Phys. 114, 164304 (2013); doi: 10.1063/1.4826529 (Received 24 July 2013; accepted 6 October 2013; published online 22 October 2013) A comprehensive analysis of electrical, electromagnetic (EM), mechanical, and thermal properties of epoxy resin composites filled with 0.25–2.0 wt. % of carbon additives characterized by high surface area, both nano-sized, like carbon nanotubes (CNTs) and carbon black (CBH), and micro-sized exfoliated graphite (EG), was performed. We found that the physical properties of both CNTs- and CBH-based epoxy resin composites increased all together with filler content and even more clearly for CBH than for CNTs. In the case of EG-based composites, go…

Swift heavy ion induced modifications of luminescence and mechanical properties of polypropylene/ZnO nanocomposites

Abstract The effect of irradiation with 150 MeV Kr ions at fluencies 10 11 and 10 12  ions/cm 2 on luminescence of PP/ZnO nanocomposites and PP matrix has been studied. In unirradiated composite the luminescence is comparatively weak and is contributed mainly by the excitonic luminescence of ZnO. Irradiation of nanocomposite and PP matrix leads to a strong increase of luminescence intensity in a wide spectral range of 360–600 nm. It follows from the obtained results that the enhancement of luminescence originates mainly from the broken bonds in PP matrix. Ion-induced scission of polymer bonds and fragmentation of polymer chains is deduced also from the nanoindentation tests which show a rem…

Elastic properties of UV irradiated polyethylene-octene copolymer composites with functionalized multi-walled carbon nanotubes

ABSTRACTPolyethylene-octene copolymer (E38) is melt compounded with carboxylated carbon nanotubes (CNT-COOH) in the presence of maleic anhydride grafted polyethylene (PEgMA). The effects of CNT-COOH in the amount of 1–10 wt. % on the mechanical properties of E38 based composite are investigated. It is revealed that addition of CNT-COOH considerably increases the stiffness and mechanical strength of the E38 based composites. The effect of UV irradiation on the structure as well as on the mechanical properties of E38/PEgMA/CNT-COOH composites is also investigated. Results of the investigation testify that UV resistance of the E38 based composites increases by increasing the content of CNT-COO…

Elasticity and long-term behavior of recycled polyethylene terephthalate (rPET)/montmorillonite (MMT) composites

Abstract Recycled polyethylene terephthalate (rPET) nanocomposites with various amounts of montmorillonite clay (MMT) have been manufactured by using twin screw extrusion. By rising MMT weight content Wf up to 1 wt.% it is possible to increase yield strength and ultimate strength of the composite by 17% and 27% respectively in comparison to neat rPET. Introduction of MMT in the rPET leads also to considerable increase of the modulus of elasticity E. Relationship E(Wf), however, is non-linear and is characterized by slow-down in E growth along with increasing MMT content. At low nanofiller content experimental results are sufficiently well described by using the method of Mori–Tanaka and the…

Recycled Polycarbonate Based Nanocomposites

Post-consumer polycarbonate (RPC) blends with various amounts (5, 10, 30 wt. %) of ethylene vinyl acetate copolymer (EVAc) are investigated as potential nanocomposite matrices. At EVAc weight content of 10 wt.% maximum tensile strength σM and impact strength AI increase is observed in comparison to neat RPC. Addition of EVAc, however, reduces resistance to creep as well as decrease thermal stability of the investigated compositions. Addition of montmorillonite nanoclay (MMT), however, allows increase modulus of elasticity E and yield strength σY of the investigated RPC blend with 10 wt. % of EVAc. Besides it creep resistance and thermal resistance of the investigated system is increased to …

Fotoalbums un tā dizaina izveides principi

Latvijas Universitātes Pedagoģijas, psiholoģijas un mākslas fakultātes Mākslas profesionālā bakalaura studiju programmas 4. kursa studentes Tatjanas Ivanovas bakalaura darba “Fotoalbums un to dizaina izveides principi” mērķis ir izveidot fotoalbumu, balstoties uz teorētiskajā daļā iegūtajām zināšanām un pētījumā iegūtajiem rezultātiem. Teorētiskajā daļā tiek apkopota informācija par dažādiem tematiem – vēsturi, konceptuālo īpatnību, funkcionālo uzdevumu, informācijas raksturu, radīšanas principu, ekonomiskajiem un organizatoriski tehniskajiem nosacījumiem, konstrukciju un to noformēšanas īpatnībām. Empīriskajā daļā tiek veikta informācijas analīze un izvēlēto fotoalbumu dizaina salīdzinājum…

Modification of polyoxymethylene for increased thermal resistance

Ternary nanocomposites, composed of polyoxymethylene (POM), ethylene octene copolymer and zinc oxide (ZnO), are prepared by melt compounding. The effects of two types of ethylene-octene copolymers, differing with α-octene content (38% for EOC38 and 17% for EOC17), as well as nanostructured ZnO on thermal behavior of POM are investigated. The content of EOC in the POM based composites is varied between 10 and 50 wt%, while the content of ZnO is 2 wt%. Thermal behavior of POM based systems are studied by using differential scanning calorimetry and thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. Results of thermogravimetric analysis show that, by rising either …

Properties of radiation-modified blends of polyethylene with elastomers and liquid crystalline copolyester

The results are given on the effect of γ-irradiation on properties of blends of high and low-density polyethylene (HDPE, LDPE) with elastomers -ethylene/propylene/diene rubber (EPDM) and chlorinated polyethylene (CPE), and thermotropic liquid crystalline polymer (LCP). The morphological, thermal, mechanical properties (including thermosetting properties) and adhesion properties of blended composites were investigated. A special attention was paid to the applicability of the blends as thermosetting materials (TSM). The LCP used was a copolyester of poly(ethylene terephthalate) with p-(hydroxybenzoic acid) in the ratio 40: 60. It was found that addition of LCP essentially influenced the therm…

The effect of introduction of montmorillonite clay (MMT) on the elastic properties of polycarbonate (PC) composition with acrylonitrile-butadiene styrene (ABS)

Abstract Polycarbonate (PC)/acrylonitrile–butadiene–styrene terpolymer (ABS)/montmorillonite (MMT) nanocomposites have been obtained by melt compounding in a twin-screw extruder. Structural and elastic properties have been characterized. The theoretical analysis of the elastic properties of PC/ABS/MMT composite with a widely varied number of elementary layers in clay filler particles has been performed in order to estimate the influence of the degree of exfoliation of particles on the effect of reinforcement of the material. Results of the theoretical analysis have been compared with the experimental data about the effects of unmodified and two types of organically modified montmorillonite …

Impact of non-functionalized and ionic liquid modified carbon nanotubes on mechanical and thermal properties of ethylene- octene copolymer nanocomposites

In this article the development and characterization of composites made from metallocene based ethylene-octene copolymer (EOC) with 38% octene content, non-modified or modified multi walled carbon nanotubes (MWCNTs), covalently functionalised with long chain hexadecyl moiety imidazolium ionic liquid (IL-f-MWCNTs), is presented. The procedure of MWCNTs functionalization is discussed. In order to obtain a good dispersion of the filler, composites with MWCNTs and IL-f-MWCNTs in the concentration range of 0.5-12 wt.% were made by ultrasonication / thermoplastic mixing method. The results indicated improvement in mechanical properties with increase of the filler content. The methodology of the d…

Spēles 3-4 gadus vecu bērnu valodas apguves sekmēšanai

Kvalifikācijas darba nosaukums: Spēles 3-4 gadus vecu bērnu valodas apguves sekmēšanai. Darba autore: Tatjana Ivanova. Zinātniskā darba vadītāja Antra Randoha. Pētījuma mērķis: ir izpētīt spēļu nozīmi valodas attīstībā 3-4 gadus veciem bērniem. Darbs sastāv no ievada, 3.nodaļām, secinājumiem, izmantotās literatūras un avotu saraksta. Darbam ir 2 pielikumi, 3 attēli, 5.tabulas. Darba apjoms: Teorētiskajā daļā izmantoti 41 autoru darbi. Teorētiskajā darba daļā analizēta teorētiskā literatūra un pētījumi par spēles nozīmi valodas attīstībā, spēles klasifikāciju, spēles veidiem un pētījumi par spēles nozīmi valodas attīstībā. Raksturots 3 – 4 gadus vecu bērnu valodas attīstība, prasmes v…

Liquid Crystalline Copolyester Made from Recycled Polyethylene Terephthalate and p-Acetoxybenzoic Acid: Synthesis, Characterization and Blending with Recycled Polyethylene Terephthalate

Starch Based Biodegradable Nanocomposites: Structure and Properties

Plasticized starch (PS)/montmorillonite clay (MMT) nanocomposites were prepared by casting technique. Structural features, stress-strain characteristics and sorption properties were investigated. Upon introduction of rather small amounts of MMT, the PS parameters of the mechanical and barrier properties considerably improve. Tensile strength and elastic modulus of the materials examined decrease with increased moisture content, but the effect of reinforcement of PS with MMT nanoparticles remain intact.

&lt;title&gt;Influence of strong static magnetic field on human cancer HT 1080 cells&lt;/title&gt;

The aim of this study was to investigate strong uniform magnetic field influence on the human cancer cells HT 1080. The cells were treated with magnetic field of intensity 1,16 Tesla and with anticancer agent - cis-platinum 0.025 mg/ml or vincristinum 2-3 ng/ml. The intact and the treated cell samples were incubated in a medium with acridine orange (AO). The magnetic field after 15 minutes of influence significantly increased cytoplasmic red fluorescence. Increased AO accumulation in lysosomes suggested to cancer cell metabolic activity stimulation.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Recycled Polycarbonate Blend as Matrix for Development of Polymer Nanocomposite

Summary: Secondary polycarbonate (SPC) is modified with various amounts (5, 10, 30 wt%) of ethylene vinyl acetate copolymer (EVAc) in order to reduce its brittleness. It is observed that at optimal EVAc weight content maximum tensile strength σM and impact strength AI increse by 14% (ωEVAc = 5 wt%) and 450% (ωEVAc = 10 wt%) in comparison to neat SPC, respectively. Addition of montmorillonite nanoclay (MMT) allowed further increase of elastic modulus E, strength and creep resistance of the investigated SPC blend with 10 wt% of EVAc.

Podologa profesionālo kompetenču veidošanās profesionālajā studiju programmā

Maģistra darba „Podologa profesionālo kompetenču veidošanās profesionālajā studiju programmā” mērķis - izpētīt podologa profesionālo kompetenču veidošanos studiju programmas īstenošanas procesā. Darba teorētiskajā daļā ar zinātniskās literatūras analīzes palīdzību analizēta podologa profesionālo kompetenču veidošanās pirmā līmeņa profesionālajā studiju programmā. Pētījuma teorētisko bāzi veido autori: Berliner C., Gage N., 1999; Miller M.A., Babcock D., 1996; Erikson E., 1998; Garleja R., 2003; Karpova Ā., 1998; Koķe T., 1999; Maslo E., 2003 u.c. Kvalitatīvajā empīriskā pētījuma daļā, lai noskaidrotu podologa profesionālās kompetences, to veidošanos, izmantota dziļā intervija. Raksturvārdi:…

Thermal and elastic properties of poly(vinyl chloride) (PVC) + chlorinated polyethylene (CPE) blends

Eight types of PVC + CPE blends with different weight ratios (PVC/CPE = 100/0, 90/10, 80/20, 60/40, 40/60, 20/80, 10/90, and 0/100) are tested. Data on the heat conductivity, thermal diffusivity, and heat capacity of the blends investigated are reported. Primary attention is paid to the structural approach for effective elastic constants: bulk, shear, and Young's modulae. The blends are considered as random mixtures of two isotropic constituents. It is found that the elastic moduli may be well represented by the Kerner and Budiansky equations.