Smart Materials Technologies III

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Authors: Florentino Soriano-Corral, José F. Hernández-Gámez, Lyndon H. I. Durón-Sánchez, Luis Francisco Ramos de Valle, Myriam Lozano-Estrada, Yair A. Soto-Lara
Abstract: Addition of different contents of ground tire rubber (GTR) of different particles size in crosslinked-foamed compounds based on low density polyethylene (LDPE)/ethylene vinyl acetate (EVA) was studied. Compounds were made by melt mixing in an internal mixer at 100°C and 60 rpm. Trigonox 145-45B as crosslinking agent, azodicarbonamide (ADC) as chemical blowing agent (CBA) and ZnO/SiO2 as foaming co-agents, were used. GTR of 149, 74, and 44 μm particle size was incorporated as “cell nucleating agent”, each particle size at 5, 10, and 20 phr. Morphological parameters such as average cell size (d), cell size distribution and cellular density (NC) were evaluated from images acquired by scanning electron microscopy (SEM). The results obtained from the SEM characterization show a significant reduction of d, a significance increment on NC, up to 5.81*105 to 3.62*107 cells/cm3 and a better homogenization of the cell size distribution in the foamed compounds with high GTR contents of the smaller particle size.
Authors: Li He, Thomas L. Attard
Abstract: A new fiber (x) reinforced Dynamic Covalent epoxy-polyurea Interface (x-DCEPI) shows good mechanical energy transferability of impact and vibration forces. The bonding property of x-DCEPI interface, engendered between curing, or reactive, epoxy and dynamic polyurea, is controlled by epoxy curing time (tc). The reaction of curing epoxy, where tc is a thermodynamic processing parameter, and fast-curing/ dynamic aliphatic polyurea, which lacks polyol in its resin chain extender, is linked to bulk mechanical energy transfer, quantified specifically via the loss modulus of x-DCEPI. The parameter tc effectuates designable chemical bond properties within x-DCEPI. Using Generalized Maxwell models, viscoelastic properties of epoxy, polyurea, and x-DCEPI are predicted, and results are verified using Dynamic Mechanical Analysis (DMA). The Maxwell models for x-DCEPI, as a function of tc, are used in a finite element analysis (ABAQUS) to control performance of dynamically loaded structures.
Authors: Yi Wei Fei, Jun Ma, Shian Sun, Li Ping Tong, Hong Ming Liu
Abstract: Silane coupling agent is applied to modify polypropylene fiber. The modification effectively transfers the hydrophobic surface of polypropylene fiber to hydrophilic surface. Results from FT-IR, SEM and contact angle meter suggest that that the surface functional groups, the morphology and hydrophilia of polypropylene fiber is changed during the hydrolysis reactions of silane coupling agent. The modification process not only improve the surface hydrophilia of polypropylene fiber, but also convert the smooth surface of unmodified fibers to rough surface of modified fibers which gives stronger interface bonding force between fiber and substrate in the field of composite applications.
Authors: David Lokhat, Irshaan Sewlala, Diajal Hooblal, Bradley Paul
Abstract: Aqueous solutions of sodium polytungstate were used to fractionate samples of sugarcane bagasse ash by heavy media separation. Practically no cenospheres were recovered from the ash samples. The method was successful in separating fibrous carbonaceous particles with a uniform surface from particles containing more silica and having a less uniform surface. A geopolymer refractory brick having satisfactory durability was produced from sugarcane bagasse ash with metakaolin and ball clay fillers and a sodium metasilicate/hydroxide activator liquor. Drying and firing shrinkage, bulk density and ultimate compressive strength tests were performed to determine the most feasible combination of ingredients. Geopolymer samples produced using aluminium powder instead of ball clay were found to be very brittle and unsuitable for refractory service.
Authors: Shynggys Sadyk, Timur Sh. Atabaev
Abstract: In this study, a facile method was used to prepare ZnO tetrapods for potential dye degradation applications. Field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDX) and UV-Vis spectroscopy were employed to investigate the morphology, chemical composition, and photocatalytic properties of prepared ZnO tetrapods. A Rhodamine B (RB) dye was used as a model dye to study the photocatalytic activity of the prepared sample. It was shown that RB dye can be efficiently degraded in the presence of ZnO tetrapods under continuous UV-light illumination. Thus, prepared ZnO tetrapods with excellent photocatalytic properties can be potentially used in wastewater treatment.
Authors: Lucia Rozumová, Barbora Legátová, Jana Prehradná
Abstract: The aim of this paper was to study of biosorption by use waste material as a biosorbent. Waste material used in this work was activated industrial hemp shives (Cannabis sativa), which occurs during the processing of hemp shives grown as the waste biomass in the processing process. The sorbent was utilized to reduce the content of Cu(II) ions from aqueous solutions. Sorption experiments of the cannabis hemp shives were conducted in a batch mode by use the model solutions of Cu(II). The impact of pH, contact time and initial concentration on the pollutant removal efficiency was observed. The sorption kinetics were evaluated with pseudo-first and pseudo-second order kinetic models. Adsorption process has been modeled by the Langmuir, Freundlich, Temkin and Dubinin‑Radushkevich isotherms using linear regression. The results of this study indicated that the application of hemp shives of Cannabis sativa waste material as a biosorbent is highly effective for the removal copper ions from wastewater.
Authors: Feng Shao, Jia Jia Zhuang, Gang Luo, Ke Zhang, Chang Jiang Li, Hai Feng Zhu, Jia Ping Tong
Abstract: A new three-dimensional metal-organic complex, [{Fe (NCSe)2}3(TPB)4]x(guest), was prepared with the ligand of TPB (1,3,5-tris (4-pyridyl) benzene). The X-ray single crystal diffraction studied in 100 K and 173 K shown the change of bonds and angles of the framework. The guest exchange and magnetic properties indicated that the 3D framework can be responsible to the solvent guest molecules and shows guest-dependent spin-crossover behaviour.
Authors: Ramón Díaz de León, Ricardo López, Luis Valencia, Ricardo Mendoza, Judith Cabello, Javier Enríquez
Abstract: Syntheses of biolestomers through the coordination polymerization of terpenes, such as ocimene (Oc), β-myrcene (My) and trans-β-farnesene (Fa), using catalyst systems based on neodymium versatate (NdV3) are reported in this work. All polymerization products were characterized by size exclusion chromatography, differential scanning calorimetry and nuclear magnetic resonance in order to determine their macromolecular, thermal and structural characteristics. The NdV3 in combination with diisobutylaluminum hydride as cocatalyst and diethylaluminum chloride (DEAC) as halogen source was found effective for Oc polymerizations providing polyocimenes with molecular weights (Mn) in the order of 20 to 57 Kg/mol, broad molecular weight distributions (Mw/Mn) since 3.8 until 8.2, preferably cis-1,4 content (61-69 %) and glass transition temperatures (Tg) in the range of-30 to-26 °C. On the other hand, the same NdV3 but now activated by modified methylaluminoxane and DEAC was found considerably active in My and Fa polymerizations, affording polymyrcenes and polyfarnesenes with Mn between 155 and 243 Kg/mol, as well as Mw/Mn ranging between 3.1-3.9 and 1,4 content values were found higher than 94 % for this subfamily of polyterpenes, being the 3,4 content the complement for completing 100 %. Moreover, it was demonstrated that Tg of polyterpenes studied depends on the size of pendant group, shifting it towards lower temperatures as increasing the size of the pendant group.
Authors: Nongnapas Yooruengdech, Suthisa Ontong, Thirawudh Pongprayoon
Abstract: Carbon nanotubes (CNTs) were modified by grafting polymerization with copolymer of polyaniline and poly (vinyl acetate) for improving their electrical conductivity and water dispersion. After surface modification of CNTs, they were used to fabricate as the photoelectrode or working electrode for the dye-sensitized solar cell (DSSC). The characterizations of the modified CNTs were done by FTIR, TEM and SEM. Lastly, the efficiency of DSSC prepared from the modified CNT was evaluated by photovoltaic test. The results showed the high performance of the grafting CNTs-added working electrode.
Authors: Onnicha Rattanopas, Worawut Naewrittikul, Thanyalak Chaisuwan
Abstract: Nanoporous carbon was successfully prepared by using polybenzoxazine synthesized from bisphenol-A, melamine and formaldehyde as a precursor. The varied HCl amounts have been added into the pre-polymer solution as a catalyst for the ring-opening polymerization. The reaction was traced by FTIR and DSC. In addition, the degradation behavior was studied by TGA and the textural properties were characterized by SEM and surface area analysis (AS1-MP). The nanoporous carbon obtained showed the highest char yield up to 48%. The interconnected structure from the SEM images of the nanoporous carbon exhibited significantly high surface area of 632 m2/g, high total pore volume up to 1.78 cm2/g, small average pore diameter and narrow pore size distribution detected by AS1-MP. After the activation process, the surface area has been drastically improved leading to the increasing of surface area and total pore volume up to 1119 m2/g and 1.93 cm2/g, respectively. In order to further study on the enhancement of surface area, NaCl, a water soluble compound, has been used as a template. As a result, the surface area has been improved up to 1516 m2/g.

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