Hydrothermal Synthesis of CuO/RuO2/MWCNT Nanocomposites with Morphological Variants for High Efficient Supercapacitors

In this study, we develop the optimum composition of copper oxide/ruthenium oxide and multi-walled carbon nanotubes (CuO/RuO2/MWCNTs) ternary nanocomposite via a hydrothermal method as an efficient electrode material for supercapacitor applications. The ratio between CuO and RuO2 varied to improve the electrochemical performance of the electrode. The synthesized nanocomposites are analyzed by high-resolution scanning electron microscopy (HR-SEM), thermo gravimetric analyzer (TGA) and electrochemical impedance spectroscopy (EIS). Furthermore, the elemental composition is analyzed by energy dispersive X-ray (EDX) spectroscopy and the specific capacitance was analyzed by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) methods. The electrochemical investigations is conducted in a three-electrode system and the sample is attached on a stainless steel plate as the working electrode; platinum wire works as the counter electrode and Ag/AgCl electrode as the reference electrode, adopting 3 M (NH4)2SO4 as the electrolyte. The resultant of CuO/RuO2/MWCNT nanocomposite with 7 wt% Cu and 20 wt% Ru was found to perform the highest specific capacitance of 461.59 F/g in a current density of 1 A/g.

Immobilization of K7PW11O39 on ZrO2 Nanofiber: Ultra-deep Desulfurization Based in Extraction Catalytic Oxidation Desulfurization System

In this work, K7PW11O39 (abbreviated as PW11) was immobilized on ZrO2 nanofibers and used as an efficient recyclable catalyst in extraction catalytic oxidation desulfurization system (ECODS).The 500 ppm DBT model oil(5mL) can desulphurize completely within 20 min with the catalytic conditions of 50��, 0.010 g 50 wt%- CTAB�C PW11�CZrO2 nanofibers and O/S molar ratio H2O2/DBT molar ratio�� was 2:1. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and thermo gravimetric analyzer (TGA). The results indicated the PW11�CZrO2 nanofibers were synthesized successfully and the possible catalytic mechanism is also revealed.

PEMBUATAN POLIURETAN ELASTOMER RAMAH LINGKUNGAN BERAZASKAN JATROPHA OIL

Pada penelitian ini dilakukan tentang pembuatan poliuretan berbasis Metilen difenil diisosianat (MDI) dan minyak jarak pagar dengan menggunakan etil asetat, dibutiltin dilaurat, metal laurat, nano tio2 , pentaeritritol, dan aquades sebagai pengisi tambahan yang bertujuan untuk meningkatkan sifat mekanik poliuretan. Tujuan penelitian ini adalah untuk menentukan pengaruh massa MDI dan minyak jarak pada pembuatan poliuretan dengan memvarisikan bahan utamanya. Karakteristik analisa stabilitas termal menggunakan alat TGA (Thermo Gravimetric Analyzer) menunjukkan keandalan termal yang sangat baik memiliki stabilitas termal, kapasitas penyimpanan panas laten yang tinggi, dan stabilitas siklus termal yang unggul dengan ketahanan termal hingga 403.65C°C. Pada analisa gugus fungsi menggunakan FT-IR spektroskopis gugus N-H pada daerah separan 132.24 cm-1, pada daerah serapan 3620.39 cm-1 merupakan gugus O-H dan daerah serapan 1541.12 cm-1 merupakan gugus C=C (MDI). Sedangkan analisa struktur morfologi menggunakan alat SEM (Scanning Electron Microscope) pada sampel PU sampel A memiliki permukaan halus dan menandakan partikel padat sebagai penstabil yang baik (emulsi pickering) dibangdingkan dengan sampel B yang menunjukkan beberapa bentuk agregat yang menggumpal dan berpori-pori besar, serta permukaan yang lebih halus.Kata kunci : Poliuratan, MDI, Minyak Jarak, PCM

Preparation and Gas Sensing Properties of PANI/SnO2 Hybrid Material

A sensor operating at room temperature has low power consumption and is beneficial for the detection of environmental pollutants such as ammonia and benzene vapor. In this study, polyaniline (PANI) is made from aniline under acidic conditions by chemical oxidative polymerization and doped with tin dioxide (SnO2) at a specific percentage. The PANI/SnO2 hybrid material obtained is then ground at room temperature. The results of scanning electron microscopy show that the prepared powder comprises nanoscale particles and has good dispersibility, which is conducive to gas adsorption. The thermal decomposition temperature of the powder and its stability are measured using a differential thermo gravimetric analyzer. At 20 °C, the ammonia gas and benzene vapor gas sensing of the PANI/SnO2 hybrid material was tested at concentrations of between 1 and 7 ppm of ammonia and between 0.4 and 90 ppm of benzene vapor. The tests show that the response sensitivities to ammonia and benzene vapor are essentially linear. The sensing mechanisms of the PANI/SnO2 hybrid material to ammonia and benzene vapors were analyzed. The results demonstrate that doped SnO2 significantly affects the sensitivity, response time, and recovery time of the PANI material.

Preparation of Polyimide @ Polypyrrole/Palladium Hollow Composites with Applications in Catalysis

Polyimide based hollow composites were successfully prepared by combining the situ and template methods together. Firstly, the complete words (PPy) shell was covered on the surface of polystyrene nanoparticles, then the polyamide acid and PdCl2 were covered on the surface of the materials after the calcination. Finally, PI@ PPy/Pd hollow composites were obtained by a chemical process. The structure and composition of composites were characterized by scanning electron microscopy X-ray diffraction, thermo gravimetric analyzer and differential scanning calorimeter, respectively. Palladium (Pd) nanoparticles were densely and uniformly anchored on the surface of PPy shell due to the coordination interaction between amino groups on PPy backbone and Pd2+ ions. They are ideal candidates as nanoreactors for heterogeneous catalysis due to their special structure. The catalytic performance of PI@ PPy/Pd hollow composites were studied by the reduction of NaBH4 as a reducing agent. The catalytic performance of composites was characterized by ultraviolet and visible spectrophotometer. The PI@PPy/Pd composites showed excellent catalytic performance in the reduction of methylene blue with sodium borohydride as reducing agent. The dye completely turned colorless as seen within 2.0 minutes.

On the Development of Thermochemical Hydrogen Storage: An Experimental Study of the Kinetics of the Redox Reactions under Different Operating Conditions

This work aims at investigating the reduction/oxidation (redox) reaction kinetics on iron oxide pellets under different operating conditions of thermochemical hydrogen storage. In order to reduce the iron oxide pellets (90% Fe2O3, 10% stabilizing cement), hydrogen (H2) is applied in different concentrations with nitrogen (N2), as a carrier gas, at temperatures between between 700 ∘C and 900 ∘C, thus simulating the charging phase. The discharge phase is triggered by the flow of a mixture out of steam (H2O) and N2 at different concentrations in the same temperature range, resulting in the oxidizing of the previously reduced pellets. All investigations were carried out in a thermo-gravimetric analyzer (TGA) with a flow rate of 250mL/min. To describe the obtained kinetic results, a simplified analytical model, based on the linear driving force model, was developed. The investigated iron oxide pellets showed a stable redox performance of 23.8% weight reduction/gain, which corresponds to a volumetric storage density of 2.8kWh/(L bulk), also after the 29 performed redox cycles. Recalling that there is no H2 stored during the storage phase but iron, the introduced hydrogen storage technology is deemed very promising for applications in urban areas as day-night or seasonal storage for green hydrogen.

Effects of Boron Carbide on Coking Behavior and Chemical Structure of High Volatile Coking Coal during Carbonization

Modified cokes with improved resistance to CO2 reaction were produced from a high volatile coking coal (HVC) and different concentrations of boron carbide (B4C) in a laboratory scale coking furnace. This paper focuses on modification mechanism about the influence of B4C on coking behavior and chemical structure during HVC carbonization. The former was studied by using a thermo-gravimetric analyzer. For the latter, four semi-cokes prepared from carbonization tests for HVC with or without B4C at 450 °C and 750 °C, respectively, were analyzed by using Fourier transform infrared spectrum and high-resolution transmission electron microscopy technologies. It was found that B4C will retard extensive condensation and crosslinking reactions by reducing the amount of active oxygen obtained from thermally produced free radicals and increase secondary cracking reactions, resulting in increasing size of aromatic layer and anisotropic degree in coke structure, which eventually improves the coke quality.

Effect of Temperature, Time, and Cooling Rate on the Mineralogy, Morphology, and Reducibility of Iron Ore Sinter Analogues

Analogue sinter tablets were produced at temperatures between 1250°C and 1320°C, with a range of hold times and cooling rates. Platy silico-ferrite of calcium and aluminum (SFCA) morphology was identified in samples produced at 1250°C using reflected light microscopy; however, quantitative x-ray diffraction (XRD) identified the presence of the SFCA phase, with no SFCA-I detected. This proves that the platy SFCA morphology common in analysis by reflected light microscopy cannot be attributed to the SFCA-I mineral without further analysis. Micro-XRD and electron probe micro-analysis (EPMA) were carried out on an area of platy SFCA confirming this result. The sinter analogue tablets were reduced in a 30% CO, 70% N2 gas mixture at 900°C in a tube furnace thermo-gravimetric analyzer. The degree of reduction of the tablets in this study was found to be controlled by the porosity of the samples, rather than by the morphology or mineralogy of the bonding phase.

Creep and morphological evaluation of polypropylene waste modified asphalt for pavement applications

Synoptic findings by researchers have revealed tremendous physic-chemical improvements of polymer modified mixes over the conventional asphalt. Traditionally, laboratory mechanical properties were carried out for asphalt testing, but cannot calibrate simple performance test (SPTs) criteria for fatigue and field performance. Marshall test-sized specimens of polymer asphalt mixtures were engineered with arbitrary contents of 0 to 3.0% polypropylene waste admixed with 4.5 to 6.5% bitumen contents based on relevant literature. Creep deformation involves uniaxial static creep (USC) test using BS 598-111. Morphological examinations were test with Hitachi S-4700 field-emission scan-electron-microscope (FE-SEM). Thirdly, thermal degradation was determined using Shimadzu TGA-50 thermo-gravimetric analyzer. The results showed creep resistivity with fatigue recovery of 23.2% and 28.9% strain reduction at 10oC and 60oC respectively from the optimal 2.0% polypropylene and 6.0% bitumen compared to the control mix. Also, the same mix produced well dispersed and better enhanced pore packaging micro-structure capable of resisting ageing volatization under severe traffic and environmental loading conditions considered. Keywords: Asphalt pavement, polypropylene, creep deformation, age volatization and microstructure

Synthesis and Characterization of Encapsulated 1-Tetradecanol for Thermal Energy Storage

Microencapsulated phase change material (PCM) is used for industrial and house hold air conditioning system for longer term usage. In this study 1-Tetradecanol (C14H30O) is used as a core material. Urea (CH4N2O)-Formaldehyde (CH2O) is used as shell material. Micro capsulation is made using in-situ polymerization technique. Prepared microcapsules were tested for feasibility to use cooling system. The average size was verified using Scanning Electron microscope (SEM) and result was found 3µm and shape was observed as spherical and surface morphology was smooth. The presence of chemicals of core and shell materials was verified by Fourier Transform Infra-Red spectroscopy (FT-IR). The peak temperature of microcapsules was found as 150°C from Thermo Gravimetric Analyzer (TGA). Thermal cyclic stability was verified by Differential Scanning Calorimetry (DSC). The cyclic temperature was observed as 45.9°C and 39.78°C. These prepared microcapsules can used to control the temperature of 37°C. This prepared microcapsule can be used for room air conditioning system