41 research outputs found
Stimulation of innate and adaptive immune cells with graphene oxide and reduced graphene oxide affect cancer progression
No full textSole nanomaterials or nanomaterials bound to specific biomolecules have been proposed to regulate the immune system. These materials have now emerged as new tools for eliciting immune-based therapies to treat various cancers. Graphene, graphene oxide (GO) and reduced GO (rGO) are the latest nanomaterials among other carbon nanotubes that have attracted wide interest among medical industry players due to their extraordinary properties, inert-state, non-toxic and stable dispersion in a various solvent. Currently, GO and rGO are utilized in various biomedical application including cancer immunotherapy. This review will highlight studies that have been carried out in elucidating the stimulation of GO and rGO on selected innate and adaptive immune cells and their effect on cancer progression to shed some insights for researchers in the development of various GO- and rGO-based immune therapies against various cancers
Synthetic graphite production of oil palm trunk chip at various heating rate via pyrolisis process
Get PDFSynthetic graphite was synthesized from oil palm trunk chip in controlled heating condition or pyrolysis process. The heating rate (5 °/min, 10 °/min and 20 °/min) were varied whilst the heating temperature at 800 °C was fixed. After heat treatment process, the samples were characterized by X-Ray Diffraction (XRD) and analyzed using X’Pert Highscore Plus software. Graphite phase was analysed by XRD and it was further supported by RAMAN spectroscopy analysis to confirm the graphitic nature of the synthetic graphite obtained. The morphological study was carried out by using Scanning Electron Microscope (SEM). Based on the analysis, it was confirm that synthetic graphite was successfully synthesized by heat treatment at 800 °C (20 °/min heating rate). Synthetic graphite were observed in the form of amorphous carbon based on the XRD diffraction pattern that match with the reference code of 00-041-1487. RAMAN spectroscopy also showed the formation on D, G and 2D peaks at the respective wavenumber of 1250 cm-1, 1625 cm-1 and 2700 cm-1
paniMmagnetic Film / Helyati Abu Hassan Shaari … [et al.]
Get PDFPolyaniline (PANi) are of interest conducting polymers due to its ease of synthesis at low cost using simple equipment together with its good conductivity. However, most conducting polymers exhibited poor stability, poor mechanical properties, low thermal conductance, and being amorphous which ultimately affects their performance. Thus, copolymerization of PANi with thermoplastic is one of the methods to retain conductivity of PANi but with extra added properties such as better processability and thermal stability. Therefore, this paper presents the results of the fabrication of a conducting film by copolymerization poly(methyl methacrylate) (PMMA) a thermoplastic polymer, with PANi. In this study, a series of doped PANi with different PANi ratios were copolymerized with PMMA by a free-radical copolymerization reaction to produce a conducting copolymer film. The results from characterization análisis of the film using fourier transform infrared (FTIR) spectrometer, nuclear magnetic resonance (NMR) spectroscopy, and ultraviolet-visible (UV-Vis) spectrometer are presented, which confirmed the chemical structure of both PANi and PMMA in the copolymer. Meanwhile, an evaluation using a resistivity meter found that the prepared copolymer films exhibited conductivity at around 10-7 to 10-6 S/cm, depending on the ratio of PANi incorporated with PMMA. Taking the conductivity properties into account, the electromagnetic interference (EMI) shielding effectiveness of the films has been carried out. In summary, the prepared conducting film can be further exploited to be used as an electronic magnetic shielding material in many electronic applications. The prepared conducting copolymer film for electromagnetic shielding material prepared in this study is known as paniMmagnetic film. The novelty of this research will be in the report of copolymerization PMMA with PANi using the free radical reaction method for electronic magnetic shielding applications
Jelang satu abad muhammadiyah Aceh: sejarah perkembangan dan harapan masa depan
No full textx, 161 hlm. : ilus. ; tab. ; 21 cm
Characterization and conductivity of graphene oxide (GO) dispersion in different solvents
No full textFracture behaviour of Sn-58Bi alloy reinforced by activated bamboo charcoal
No full textSn-Bi solders are considered by PV manufacturers as acceptable Pb-free alternative due to its low operating temperature and cost, despite being prone to brittleness caused by coarse Bi phases. Bamboo charcoal (BC) is a sustainable and environment-friendly resource with high surface area and its addition to Sn-Bi solder meets the requirement of a green solder, in line with environmental regulations. This study aims to improve the shear strength and reduce brittleness of the Sn-Bi solder alloy by using a sustainable reinforcement, the activated bamboo charcoal. Sn-58Bi solder paste was reinforced with 0.25, 0.50, 0.75 and 1.00 wt.% of activated BC, respectively and reflowed to create a single lap shear joint. Aging response was determined through accelerated aging at 120 °C for 7 days and 14 days. Shear strength of the joints increased as the activated BC content increased in the as-reflowed condition and there was lower degradation in shear strength for heat-aging specimens compared to pure Sn-Bi solder. No failures occurred via Mode 3 when the as-reflowed samples contained 0.50 wt.% or more of activated BC, and the 7- and 14-day heat-aged samples were free from Mode 3 failures when the activated BC composition was at 0.75 wt.% and above. Fracture surfaces showed transitions from flat and smooth surface to elongated-dimple structures even with just 0.25 wt.% of activated BC addition. While prolonged heat-aging increased cleavage presence, increasing amounts of activated BC reduced facet numbers and dimple sizes, indicating successful suppression of Bi phase segregation
In-situ modification of SiO2 coatings on steel plates for water repellent applications
Get PDFThis study investigates the in-situ modification of cristobalite SiO₂ (SC) coatings on steel plates to enhance surface properties, with a focus on developing hierarchical structures for water-repellent applications. SC was synthesized from silica sand via co-precipitation and combined with methyltrimethoxysilane through in-situ modification using sol-gel methods. Samples were prepared with varying SC concentrations of 0, 1.5, 3, 4.5, and 6 wt%. X-Ray Diffraction (XRD) characterization confirmed the coexistence of crystalline and amorphous phases, while Scanning Electron Microscope (SEM) indicated changes in particle size and morphology due to cristobalite SiO₂ addition. Fourier Transform Infra-Red (FTIR) analysis identified Si–O–Si asymmetric stretching bonds, and Atomic Force Microscope (AFM) demonstrated the formation of hierarchical micro-submicron structures with enhanced surface roughness. The roughness factor of the sample coatings was determined through calculations based on the AFM topographical data. Hydrophobicity analysis using water contact angle (WCA) measurements showed improved performance with increasing cristobalite SiO₂ content, achieving a maximum WCA of 132.6 ± 4.1° for the sample coated on a steel plate substrate. The best performance was observed at 6 wt% cristobalite SiO₂, as it significantly increased the water contact angle and thereby enhanced the hydrophobicity of the composite. The coated steel plates exhibited excellent hydrophobic properties, offering promising potential for practical applications in water-repellent technologies
High Throughput Graphene Oxide in Modified Hummers Method and Annealing Effect on Different Deposition Method
No full textN-Doped rGO-sike carbon prepared from coconut shell: structure and specific capacitance
No full textAn rGO−like carbon compound has been synthesized from biomass, i.e., old coconut shell, by a carbonization process followed by heating at 400°C for 5 h. The nitrogen doping was achieved by adding the urea (CH4N2O) and stirring at 70°C for 14 h. The morphology and structure of the rGO-like carbon were investigated by electron microscopies and Raman spectroscopy. The presence of C-N functional groups was analyzed by Fourier transform infrared and synchrotron X-ray photoemission spectroscopy, while the particle and the specific capacitance were measured by particle sizer and cyclic voltammetry. The highest specific capacitance of 72.78 F/g is achieved by the sample with 20% urea, having the smallest particles size and the largest surface area. The corresponding sample has shown to be constituted by the appropriate amount of C–N pyrrolic and pyridinic defects
