scholarly journals Karakteristik Termal dan Fungsionalitas Komposit Silika Sekam Padi dengan Aspal

2020 ◽  
Vol 8 (1) ◽  
pp. 101-110
Author(s):  
Deafani Wahyu Ardaniswari ◽  
◽  
Josalina Josalina ◽  
Hana Haritsah ◽  
Simon Sembiring ◽  
...  

This research was carried out to investigate the effect of asphalt addition to thermal characteristics, functional groups, physical properties (water absorption, water content, and swelling thickness) of rice husk silica. The mass ratio of silica and asphalt alloys were 1:0; 1:0,4; 1:0,5; and 1:0,6. Silica and asphalt were mixed at 160˚C followed by calcination at 150˚C for 3 hours. Thermal characteristics and phase structures were analyzed using Differential Thermal Analysis/Thermo Gravimetrical Analysis (DTA/TGA), X-ray Diffraction (XRD), and Fourier Transform Infrared (FTIR). DTA/TGA analysis results show that the addition of asphalt causes a decreasing in mass, on set temperature, maximum temperature, endothermic temperature And an increase in exothermic peak temperature. The results of XRD analysis showed that the addition of asphalt resulted in the appearance of amorphous carbon, shifting the range and the highest intensity of 2θ amorphous silica. The results of FTIR analysis showed that the addition of asphalt resulted in appearance the functional grups of C-H. The addition of asphalt causes a decrease in the value of water absorption, water content, and swelling thickness.

2017 ◽  
Vol 31 (35) ◽  
pp. 1750337
Author(s):  
Guoxuan Qin ◽  
Yanan Wang ◽  
Shentong Mo ◽  
Xing Fu ◽  
Hui Wang ◽  
...  

In this paper, ZnO nanobelts have been partially high-quality synthesized employing diverse reactant mass ratios between zinc acetate [Zn(AC)2] and polyvinyl alcohol (PVA) without any catalyst. The maximum temperature required for the whole reaction process is no more than 650[Formula: see text]C. The morphologies of ZnO nanomaterials fabricated from distinct reactant concentrations have been systematically investigated by means of field-emission scanning electron microscopy (FESEM). X-ray diffraction (XRD) analysis identifies that ZnO nanobelts exhibit a typical wurtzite structure. Through fluorescence spectrometer, the photoluminescence (PL) spectra generated by ZnO nanomaterials corresponding to different reactant concentrations have disparate peak intensities and luminescence wavelengths. This phenomenon indicates that novel-synthesized ZnO nanomaterial shows great potential in changing the optical properties of light-emitting devices. In addition, synthetic ZnO nanobelts exhibit excellent UV emission capability.


2020 ◽  
Vol 978 ◽  
pp. 291-295 ◽  
Author(s):  
Agnivesh Kumar Sinha ◽  
Harendra Kumar Narang ◽  
Somnath Bhattacharya

Natural fibres have gained popularity due to their use in fabrication of biodegradable polymer composites which are not only non-polluting but are also light weight and inexpensive. Abaca fibres are known for their remarkable properties for which their polymer composites are used in automotive applications. However, hydrophilicity and compatibility with polymer matrices are the two major drawbacks of natural fibres which restrict their use as reinforcements in polymer composites. Therefore, present study deals with the surface modifications of abaca fibre using potassium permanganate and sodium hydroxide solutions to enhance crystallinity and reduce hydrophilicity of abaca fibres. Further, the surfaces of untreated and treated fibre were investigated with the help of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. Surface treatment of abaca fibre led to the removal of unwanted wax, and other amorphous materials which was confirmed through FTIR analysis. Crystallinity index was found to be 57%, 59% and 61% for untreated, NaOH treated and KMnO4 treated abaca fibre respectively.


2010 ◽  
Vol 173 ◽  
pp. 102-105 ◽  
Author(s):  
Khairul Arifah Saharudin ◽  
Srimala Sreekantan

In this paper, anodization of Ti foil was carried out in ethylene glycol (EG) containing 5 wt% NH4F solution and 0 to 1.5 wt% of water at 50 V for 60 min. The pH of the bath was kept constant at ~pH7. The crystal structure was studied by X-Ray Diffraction (XRD) analysis, and the morphology was observed via field emission scanning electron microscopy (FESEM). TiO2 nanotube with aspect ratio of 100 was obtained in EG containing less than 1wt % water. The nanotubes wall was very smooth. Increasing the water content > 1wt % results in short nanotubes of approximately 6.2μm with aspect ratio of 62. As anodized, nanotubes were amorphous and annealed at 400 °C promote 100 % anatase phase. Photocatalytic activity of the nanotubes produced at different water content was also evaluated by the degradation of methyl orange and the detail of the observation was discussed thoroughly in this paper.


2020 ◽  
Vol 17 (34) ◽  
pp. 591-598
Author(s):  
Yusif H. SHUKURLU

The enrichment of the molecular structure of silk fibroin by selenium atom led to an increase in the branching of fibroin macromolecule. As a result, the amorphous fraction of fibroin microfiber increases which leads to an increase in the strength characteristic of the silk thread. At the same time, this change in the supramolecular structure of fibroin involving a selenium atom has enabled us to study the two-modification mechanism for crystallizing fibroin microfibers. Based on studies on the use of temperature-gravimetric and X-ray diffraction (XRD) analysis and relative changes in the proportion of amorphous and crystalline regions, we came to the conclusion that fibroin microfibrils consist mainly of extended crystallites CSC – crystallites with the stretched chains. They alternate along the axis of microfiber with amorphous layers, the sizes of which are smaller than the sizes of the folded crystallites (CFC). Therefore, CFC cannot be located in amorphous layers between the CSC along the microfiber’s axis. As a result, the ability to fold branched sections of the macromolecule decreases, that is, CFC decreases. This increases the proportion of amorphous areas of microfibers of the fibroin. In the model, which is proposed by author non-crystallized in the form of CSC, segments of a macromolecule, on the sides of the central core and attached to it, restored their crystal structure (CFC) – with folded conformation of chains.


2016 ◽  
Vol 846 ◽  
pp. 63-68 ◽  
Author(s):  
Saad S. Hajer ◽  
M.K. Halimah ◽  
Azmi Zakaria ◽  
M.N. Azlan

The glass series of samarium nanoparticles (NPs) doped zinc borotellurite glasses were successfully fabricated by using conventional melt-quenching technique. The structural properties of the prepared glasses were investigated by X-ray diffraction (XRD) analysis and FTIR analysis. It was confirmed that the prepared glasses are amorphous in nature. The bonding parameters of the glasses were analyzed by using FTIR analysis and were found the formation of non-bridging oxygen. The density of these glasses were measured and found to be increased with increasing samarium NPs content. The optical absorption spectra of these glasses were revealed that the fundamental absorption edge shifts to higher wavelengths as the content of Sm2O3 (NPs) increases. The optical energy band gap are found to be decreased linearly with an increasing samarium NPs concentration which is due to the formation of non-bridging oxygen in the glass system.KeywordsBorotellurite glass; optical band gap, Samarium nanoparticles.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 549
Author(s):  
Katarzyna Borek ◽  
Przemysław Czapik

This paper aims to investigate the possibility of using waste glass of different colours as a complete substitute for quartz sand in autoclaved silica–lime samples. On the one hand, this increases the possibility of recycling waste glass; on the other hand, it allows obtaining autoclaved materials with better properties. In this research, reference samples with quartz sand (R) and white (WG), brown (BG), and green (GG) waste container glass were made. Parameters such as compressive strength, bulk density, and water absorption were examined on all samples. The samples were examined using a scanning electron microscope with an energy dispersive spectroscopy detector (SEM/EDS) and subjected to X-ray diffraction (XRD) analysis. The WG samples showed 187% higher compressive strength, BG by 159%, and GG by 134% compared to sample R. In comparison to the reference sample, volumetric density was 16.8% lower for sample WG, 13.2% lower for BG, and 7.1% lower for GG. Water absorption increased as bulk density decreased. The WG sample achieved the highest water absorption value, 15.84%. An X-ray diffraction analysis confirmed the presence of calcite, portlandite, and tobermorite phases. Depending on the silica aggregate used, there were differences in phase composition linked to compressive strength. Hydrated calcium silicates with varying crystallisation degrees were visible in the microstructure image.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Azlan Muhammad Noorazlan ◽  
Halimah Mohamed Kamari ◽  
Siti Shafinas Zulkefly ◽  
Daud W. Mohamad

Erbium nanoparticles (NPs) doped zinc borotellurite glasses have been prepared by conventional melt-quenching technique with the chemical composition{[(TeO2)0.70(B2O3)0.30]1-x(ZnO)x}1-y(Er3O2)y(wherey=0.005,0.01,0.02,0.03,0.04,0.05). The structural properties of the prepared glasses were determined via X-ray diffraction (XRD) analysis and FTIR analysis. It was confirmed that the prepared glasses are amorphous. The bonding parameters of the glasses were analyzed by using FTIR analysis and were confirmed to be ionic in nature. The refractive index increases as the content of erbium NPs increases. The optical absorption spectra revealed that fundamental absorption edge shifts to longer wavelength as the content of erbium NPs increases. The value of band gap had been calculated and shown to be decreased with an increase content of erbium NPs. The Urbach energy was shown to be linearly increased with an increase content of erbium NPs oxides.


TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.


Author(s):  
Erdoğan Karip ◽  
Mehtap Muratoğlu

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.


Sign in / Sign up

Export Citation Format

Share Document