scholarly journals Characterization of Bacterial Nanocellulose - Graphite Nanoplatelets Composite Films

Author(s):  
Bili Darnanto Susilo ◽  
Heru Suryanto ◽  
Aminnudin Aminnudin

Bacterial cellulose (BC) was synthesized from pineapple peel extract media with addition of fermentation agent bacteria Acetobacter xylinum. BC was disintegrated from the pellicle into bacterial nanocellulose (BNC) by using a high-pressure homogenizer (hph) machine, which has a three-dimensional woven nanofibrous network. The synthesis of composite films started when BNC, graphite nanoplatelets, and cetyltrimethylammonium bromide (CTAB) were homogenized using an ultrasonic homogenizer then baked on a glass mold at a temperature of 80 degrees Celcius for 14h. A scanning electron microscope (SEM) was used to analyze its morphology. X-Ray diffraction spectra were used to analyze the composite films structure. The functional groups of the composite films were analyzed using the FTIR spectrum. SEM micrograph shows that GNP was evenly distributed into BNC matrix after CTAB addition. GNPs are shown as flat and smooth flakes with sharp corners. Some peak corresponds O-H, C-H, C≡C, and CH3 stretching was identified by using FTIR spectroscopy at wavenumber 3379, 2893, 2135, and 1340 cm-1, respectively. XRD analysis shows that Crystalline Index (C.I) of BNC increases after 2.5 wt% addition of GNP. The presence of CTAB decreases C.I value of composite films. BNC/GNP composite films have the best mechanical properties with Young’s modulus about 77.01 ± 8.564.

2020 ◽  
Vol 849 ◽  
pp. 113-118
Author(s):  
Yayat Iman Supriyatna ◽  
Slamet Sumardi ◽  
Widi Astuti ◽  
Athessia N. Nainggolan ◽  
Ajeng W. Ismail ◽  
...  

The purpose of this study is to characterize Lampung iron sand and to conduct preliminary experiments on the TiO2 synthesis which can be used for the manufacturing of functional food packaging. The iron sand from South Lampung Regency, Lampung Province that will be utilized as raw material. The experiment was initiated by sieving the iron sand on 80, 100, 150, 200 and 325 mesh sieves. Analysis using X-Ray Fluorescence (XRF) to determine the element content and X-Ray Diffraction (XRD) to observe the mineralization of the iron sand was conducted. The experiment was carried out through the stages of leaching, precipitation, and calcination. Roasting was applied firstly by putting the iron sand into the muffle furnace for 5 hours at a temperature of 700°C. Followed by leaching using HCl for 48 hours and heated at 105°C with a stirring speed of 300 rpm. The leaching solution was filtered with filtrate and solid residue as products. The solid residue was then leached using 10% H2O2 solution. The leached filtrate was heated at 105°C for 40 minutes resulting TiO2 precipitates (powder). Further, the powder was calcined and characterized. Characterization of raw material using XRF shows the major elements of Fe, Ti, Mg, Si, Al and Ca. The highest Ti content is found in mesh 200 with 9.6%, while iron content is about 80.7%. While from the XRD analysis, it shows five mineral types namely magnetite (Fe3O4), Rhodonite (Mn, Fe, Mg, Ca) SiO3, Quart (SiO2), Ilmenite (FeOTiO2) and Rutile (TiO2). The preliminary experiment showed that the Ti content in the synthesized TiO2 powder is 21.2%. The purity of TiO2 is low due to the presence of Fe metal which is dissolved during leaching, so that prior to precipitation purification is needed to remove impurities such as iron and other metals.


2016 ◽  
Vol 98 ◽  
pp. 70-74
Author(s):  
Andrius Laurikėnas ◽  
Jurgis Barkauskas ◽  
Aivaras Kareiva

In this study, lanthanide elements (Ln3+) and 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid (TFBDC) based metal-organic frameworks (MOFs) were synthesized by precipitation and diffusion-controlled precipitation methods. Powders insoluble in aqueous media and polar solvents were obtained. The microstructure and properties of Ln3+ MOFs were evaluated and discussed. X-ray diffraction (XRD) analysis, infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and fluorescence spectroscopy (FLS) were carried out to characterize Ln3+ MOF's crystallinity, the microstructure, chemical composition and optical properties.


2021 ◽  
Author(s):  
nejeh hannachi ◽  
faouzi hlel

Abstract Two new organic-inorganic hybrid materials, (C6H10N2).Cl2 (I) and [C6H10N2]2ZnCl4 (II), have been synthesized by hydrothermal method and characterized by single-crystal X-ray diffraction and XRD pattern investigations. These two compounds are crystallized in the monoclinic system; C2/c space group. In the both structures, the anionic-cationic entities are interconnected by hydrogen bonding contacts and p-p Interaction forming three-dimensional networks. Intermolecular interactions were investigated by Hirshfeld surfaces and the contacts of the four different chloride atoms in (II) were compared. The vibrational absorption bands were identified by infrared spectroscopy. These compounds were also investigated by solid state 13C NMR spectroscopy.


2015 ◽  
Vol 75 (7) ◽  
Author(s):  
Amir Arifin ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Junaidi Syarif

Hydroxyapatite (HA) has been widely used in biomedical applications due to its excellent biocompatibility. However, Hydroxyapatite possesses poor mechanical properties and only tolerate limited loads for implants. Titanium is well-known materials applied in implant that has advantage in mechanical properties but poor in biocompatibility. The combination of the Titanium alloy and HA is expected to produce bio-implants with good in term of mechanical properties and biocompatabilty. In this work, interaction and mechanical properties of HA/Ti6Al4V was analyzed. The physical and mechanical properties of HA/Ti6Al4V composite powder obtained from compaction (powder metallurgy) of 60 wt.% Ti6Al4V and 40 wt.% HA and sintering at different temperatures in air were investigated in this study. Interactions of the mixed powders were investigated using X-ray diffraction. The hardness and density of the HA/Ti6Al4V composites were also measured. Based on the results of XRD analysis, the oxidation of Ti began at 700 °C. At 1000 °C, two phases were formed (i.e., TiO2 and CaTiO3). The results showed that the hardness HA/Ti6Al4V composites increased by 221.6% with increasing sintering temperature from 700oC to 1000oC. In contrast, the density of the composites decreased by 1.9% with increasing sintering temperature. 


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3035
Author(s):  
Dovydas Karoblis ◽  
Diana Griesiute ◽  
Kestutis Mazeika ◽  
Dalis Baltrunas ◽  
Dmitry V. Karpinsky ◽  
...  

In this study, a highly crystalline bismuth ferrite (BFO) powder was synthesized using a novel, very simple, and cost-effective synthetic approach. It was demonstrated that the optimal annealing temperature for the preparation of highly-pure BFO is 650 °C. At lower or higher temperatures, the formation of neighboring crystal phases was observed. The thermal behavior of BFO precursor gel was investigated by thermogravimetric and differential scanning calorimetry (TG-DSC) measurements. X-ray diffraction (XRD) analysis and Mössbauer spectroscopy were employed for the investigation of structural properties. Scanning electron microscopy (SEM) was used to evaluate morphological features of the synthesized materials. The obtained powders were also characterized by magnetization measurements, which showed antiferromagnetic behavior of BFO powders.


Author(s):  
Vineela Balisetty ◽  
Kanamaluru Vidyasagar

The quaternary A 2W3SeO12 (A = NH4, Cs, Rb, K or Tl) selenites have been prepared in the form of single crystals by hydrothermal and novel solid-state reactions. They were characterized by X-ray diffraction, thermal and spectroscopic studies. All of them have a hexagonal tungsten oxide (HTO) related [W3SeO12]2− anionic framework with pyramidally coordinated Se4+ ions. The known A 2W3SeO12 (A = NH4, Cs or Rb) compounds are isostructural with the Cs2W3TeO12 compound and have a non-centrosymmetric layered structure containing intra-layer Se—O bonds. The new compound K2W3SeO12(α) is isostructural with the K2W3TeO12 compound and has a centrosymmetric three-dimensional structure containing interlayer Se—O bonds. It is inferred that the new Tl2W3SeO12 compound has the same three-dimensional structure as K2W3SeO12(α).


Author(s):  
Farah Wahida Harun ◽  
Siti Balkis Mahamat Nor ◽  
Siti Salhah Othman

This study was carried out to immobilize molybdenyl (VI) acetylacetonate (MoO2(acac)2) complex on alumina pillared montmorillonite K-10 (MMT K-10). Pillar MMT K-10 was produced by introducing MMT K-10 with a hydrolysis solution of NaOH with AlCl3. Different concentrations of pillaring solution were prepared in terms of OHto Al3+ ratio (0.5, 1.0, 1.5 and 2.0) to observe the structural characteristics of MMT K-10. The pillared materials were then immobilized with 0.1 M MoO2(acac)2 and were characterized using X-ray diffractometry (XRD), scanning electron microscopy coupled in an energy dispersive X-ray spectrometer (SEM-EDX) and Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR) techniques. FTIR bands at ca. 890 – 930 cm-1 indicate that the Mo complex was immobilized on the surface of pillared MMT K-10 not in between the layers. This is supported by the SEM and XRD analysis where the SEM micrograph showed deposition of Mo on the surface of MMT K-10 as well as no modification of basal spacing was observed by XRD. Meanwhile, the d(001) spacing of the alumina pillared MMT K10 samples were seen to increase slightly as the concentration of OH/Al3+ increased.


2009 ◽  
Vol 24 (8) ◽  
pp. 2541-2546 ◽  
Author(s):  
Eisuke Yokoyama ◽  
Hironobu Sakata ◽  
Moriaki Wakaki

ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.


1996 ◽  
Vol 49 (7) ◽  
pp. 801 ◽  
Author(s):  
IE Grey ◽  
MR Lanyon ◽  
R Stranger

Laboratory digestion of natural and upgraded ilmenites with concentrated sulfuric acid has been carried out under conditions simulating the sulfate-route pigment process. X-Ray diffraction studies on the solid digestion cakes led to the characterization of a number of different iron titanium sulfate and oxysulfate compounds, whose formation was dependent on the ilmenite composition and digestion conditions. Two different sulfate phases were identified, with structures related to those for Fe2(SO4)3 and H2O[ Zr (HPO4)2]. Four different iron titanium oxysulfates , ( Fe,Ti )(O,OH)SO4, were identified as major digestion products, three having structures related to those for β-NbOPO4, GeOHPO4 and lazulite , Mg[AlOHPO4], and the fourth being a new struture type. The structures of the oxysulfate phases were refined by the Rietveld method. Both the sulfates and the oxysulfates have three-dimensional framework structures formed by corner linking of ( Ti,Fe )O6 octahedra and SO4 tetrahedra, and containing channels or interlayer regions that can be occupied by cations such as H3O+ and Fe2+. The different structures have many features in common. Their structural relationships are discussed and mechanisms are proposed for the phase transformations encountered in the digestion studies.


Author(s):  
M.T. Blatchford ◽  
A.J. Horlock ◽  
D.G. McCartney ◽  
P.H. Shipway ◽  
J.V. Wood

Abstract In this paper, the production of NiCr-TiC powder by SHS, suitable for HVOF spraying, is discussed together with results on the microstructure and coating properties. Compacts for SHS were prepared by mixing elemental Ti and C with pre-alloyed Ni-20wt.% Cr powder to give an overall composition of 35wt.% NiCr and 65wt.% TiC. These were then ignited and a self-sustaining reaction proceeded to completion. Reacted compacts were crushed, sieved, and classified to give feedstock powders in size ranges of 10-45 µm and 45-75 µm. All powder was characterized prior to spraying based on particle size distribution, x-ray diffraction (XRD), and scanning electron microscopy (SEM/EDS). Thermal spraying was performed using both H2 and C3H6 as fuel gases in a UTP/Miller Thermal HVOF system. The resulting coatings were characterized by SEM and XRD analysis, and the microstructures correlated with powder size and spray conditions. Abrasive wear was determined by a modified 'dry sand rubber wheel' (DSRW) test and wear rates were measured. It has been found that wear rates comparable to those of HVOF sprayed WC-17wt% Co coatings can be achieved.


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