scholarly journals Ag(I) Catalyzed Grafting of Acrylonitrile onto Gum Arabic by Ce(IV) in Medium: A Kinetic Study

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Geeta Thota ◽  
P. Srinivas
Keyword(s):  
Electron Microscopy ◽  
Gum Arabic ◽  
Probable Mechanism ◽  
Water Soluble ◽  
Graft Polymer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Water Soluble Polymer ◽  
X Ray ◽  
Scanning Electron

Grafting of Acrylonitrile (AN) onto water-soluble polymer Gum arabic (GA) was carried out using ceric ammonium sulfate [Ce(IV)] as initiator in the presence and absence of Ag(I) in H2SO4 medium at 313 K. The rate of oxidation (), rate of grafting (), and grafting efficiency (GE) were determined for catalyzed and uncatalyzed grafting and suitable mechanism was proposed to explain the observed results. No homopolymerization in the absence of GA indicates that the polymer obtained is purely a graft copolymer. A probable mechanism involving the formation of Ag(I)-GA adduct followed by its oxidation with Ce(IV) to give Ag(II)-GA adduct, and its decomposition to give initiating radicals is proposed to explain the observed results. The graft polymer was characterized using Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), X-ray diffraction, and scanning electron microscopy (SEM) considering GA as reference.

Research on compatibility and surface of high impact bio-based polyamide

2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Crystallization Behavior ◽  
High Impact ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.

scholarly journals Development of an Oxcarbazepine Solid Dispersion Using Skimmed Milk to Improve the Solubility and Dissolution Profile

2019 ◽  
Vol 11 (05) ◽  
Author(s):  
M. Shah ◽  
D. Patel
Keyword(s):  
Electron Microscopy ◽  
Solid Dispersion ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Infra Red ◽  
Crystalline Nature ◽  
Skimmed Milk ◽  
Scanning Electron

Oxcarbazepine has low solubility and low oral bioavailability, so it’s a challenge to formulate suitable dosage form. In this present investigation, to improve the dissolution rate and solubility, skimmed milk is used as a carrier. Physical mixers were prepared using various drugs to carrier ratio and spray drying technology was used to develop solid dispersion with the carrier. Various techniques were used to characterize the solid dispersion immediately after they were made which includes differential scanning calorimetry, scanning electron microscopy, fourier transform infra- red spectroscopy, X-ray diffraction and in-vitro dissolution profiles. The differential scanning calorimetry thermograms of raw drug indicated of its anhydrous crystalline nature. In thermograms of solid dispersion, the characteristic peak was absent suggesting the change from crystalline nature to amorphous form. X-ray diffraction confirmed those results. X-ray diffraction results of raw drug showed highly intense peak characteristic of its crystalline nature where solid dispersion showed less intense, more diffused peak indicating the change in crystalline form. Fourier transforms infra-red spectroscopy studies showed there was no interaction between drug and carrier. Scanning electron microscopy support the amorphous nature of mixer. The whole formulation showed distinct enhancement in the drug release behavior and solubility. The optimum oxcarbazepine to skimmed milk ratio 1:3 enhances the in-vitro drug release by 3.5 fold and also show distinct increase in solubility. It was concluded that for improvement of solubility of poorly water soluble oxcarbazepine, skimmed milk powder as a carrier can be utilize very well.

Study of an Energetic-oxidant Co-crystal: Preparation, Characterisation, and Crystallisation Mechanism

2017 ◽  
Vol 67 (5) ◽  
pp. 510 ◽  
Author(s):  
Han Gao ◽  
Wei Jiang ◽  
Jie Liu ◽  
Gazi Hao ◽  
Lei Xiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Diffraction Spectrum ◽  
Solvent Evaporation Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

<p>An energetic co-crystal consisting of the most promising military explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and the most well-known oxidant applied in propellants ammonium perchlorate has been prepared with a simple solvent evaporation method. Scanning electron microscopy revealed that the morphology of co-crystal differs greatly from each component. The X-ray diffraction spectrum, FTIR, Raman spectra, and differential scanning calorimetry characterisation further prove the formation of the co-crystal. The result of determination of hygroscopic rate indicated the hygroscopicity was effectively reduced. At last, the crystallisation mechanism has been discussed.</p>

Synthesis, Characterization and Magnetism of Nanosized Copper Ferrite

2008 ◽  
Vol 368-372 ◽  
pp. 604-606 ◽  
Author(s):  
Wei Zhong Lv ◽  
Zhong Kuang Luo ◽  
Bo Liu ◽  
Xiang Zhong Ren ◽  
Hong Hua Cai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Copper Ferrite ◽  
Sonochemical Method ◽  
Thermal Gravimetric ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir ◽  
Scanning Electron

Copper ferrite powders were successfully synthesized by sonochemical method. The resultant powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), FT-IR, differential thermal analysis-thermal gravimetric (DTA-TG), differential scanning calorimetry (DSC) and VSM. The particle saturation magnetization (Ms) is 66 emu/g and an intrinsic coercive force (iHc) is 2100 Oe when the precursor calcined at 950 °C for 15 h.

Hydriding Behaviour of Mg-C Nanocomposites

2003 ◽  
Vol 801 ◽  
Author(s):  
A. Bassetti ◽  
E. Bonetti ◽  
A. L. Fiorini ◽  
J. Grbovic ◽  
A. Montone ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Weight Ratio ◽  
Hydrogen Desorption ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Carbon Nanocomposites ◽  
X Ray ◽  
Scanning Electron

ABSTRACTMagnesium carbon nanocomposites for hydrogen storage have been synthesized by ball milling with different amount of benzene, acting as a lubricant. Their microstructure has been studied by X-ray diffraction and scanning electron microscopy, while the hydrogen desorption temperature has been tested by differential scanning calorimetry. Experimental results show that the microstructure after milling, the hydrogenation capabilities of the material and the reactivity with the air are related to the amount of additives. In particular the carbon to benzene ratio seems to play a major role. In fact, with an optimum value of carbon to benzene weight ratio of 1/6, the amount of carbon being 15 wt% of the milled mixture, a decomposition heat equal to 57% of pure MgH2 was measured, even after air manipulation of the sample.

Processing of Biodegradable Polymer Composite Using Soy Protein-Based Resin and Nanoclay

2016 ◽  
Author(s):  
Mohammad K. Hossain ◽  
Samira N. Shaily ◽  
Hadiya J. Harrigan ◽  
Terrie Mickens
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Soy Protein ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

A completely biodegradable composite was fabricated from an herbal polymer, soy protein concentrate (SPC) resin. Soy protein was modified by adding 30 wt% of glycerol and 5 wt% of poly vinyl alcohol (PVA) to enhance its mechanical as well as thermal property. 3%, 5%, 10%, and 20% nanoclay (NC) were infused into the system. To evaluate its mechanical properties, crystallinity, thermal properties, bonding interaction, and morphological evaluation, tensile, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) tests, and optical microscopy (OM) and scanning electron microscopy (SEM) evaluation were performed. Tensile tests showed that the addition of nanoclay improved the mechanical properties of the modified resin. Soy protein is hydrophilic due to the presence of amino acids that contain various polar groups such as amine, carboxyl, and hydroxyl. As a result, polar nanoclay particles that are exfoliated can be evenly dispersed in the SPC resin. From experimental results, it is clear that adding of nanoclay with SPC resin significantly increased the stiffness of the SPC resin. A combination of 5% clay, 30% glycerol, and 5% PVA with the modified SPC resulted in the maximum stress of 18 MPa and Young modulus of 958 MPa. The modified SPC showed a reduced failure strain as well. X-ray diffraction curves showed an improvement of crystallinity of the prepared resin with increasing amount of nanoclay. Interaction among soy, glycerol, PVA, and nanoclay was clearly demonstrated from the FTIR analysis. Optical microscopy (OM) and scanning electron microscopy (SEM) micrographs revealed rougher surface in the nanoclay infused SPC samples compared to that of the neat one. SEM evaluation revealed rougher fracture surface in the NC infused samples.

scholarly journals Effects of annealing parameters on phase, structure and thermochromic properties of VO2 (M) derived from nanostructured VO2(B)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hamdi Muhyuddin Barra ◽  
Soo Kien Chen ◽  
Nizam Tamchek ◽  
Zainal Abidin Talib ◽  
Oon Jew Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Different Temperatures ◽  
Thermochromic Properties ◽  
Scanning Electron

Abstract Synthesis of thermochromic VO2 (M) was successfully done by annealing hydrothermally-prepared VO2 (B) at different temperatures and times. Conversion of the metastable VO2 (B) to the thermochromic VO2 polymorph was studied using thermogravimetric analyzer (TGA) under N2 atmosphere. Moreover, the phase and morphology of the synthesized samples were studied using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. Accordingly, the XRD scans of all the annealed samples exhibited the presence of monoclinic VO2 (M), while the FE-SEM images of the samples showed the formation of nanorods and nanospheres, particularly those heated at high temperatures (650 °C and 700 °C). Meanwhile, differential scanning calorimetry (DSC) was used to measure the phase transition temperature (τc), hysteresis, and enthalpy of the prepared VO2. Based on these results, all samples displayed a τc of about 66 °C. However, the hysteresis was high for the samples annealed at lower temperatures (550 °C and 600 °C), while the enthalpy was very low for samples heated at lower annealing time (1.5 h and 1 h). These findings showed that crystallinity and nanostructure formation affected the thermochromic properties of the samples. In particular, the sample annealed at 650 °C showed better crystallinity and improved thermochromic behavior.

scholarly journals Synthesis and characterization of graphene oxide flakes for transparent thin films

2021 ◽  
Vol 22 (3) ◽  
pp. 595-601
Author(s):  
R.G. Abaszade ◽  
S.A. Mamedova ◽  
F.G. Agayev ◽  
S.I. Budzulyak ◽  
O.A. Kapush ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Graphene Oxide ◽  
Indium Tin Oxide ◽  
Electromagnetic Interference ◽  
Large Scale ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

We have synthesized large scale, thin, transparent graphene oxide (GO) flakes by Hummer’s method and investigated their suitability for fabrication of transparent nanocomposites. The GO flakes were comprehensively characterized by X-ray diffraction, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), Raman spectroscopy and Differential Scanning Calorimetry (DSC). X-ray diffraction displayed the peak of graphene oxide at 9°degree, which is characteristic peak of GO in agreement with the literature results. Scanning Electron Microscopy images revealed that thin, transparent, flake form GO with 14,8 µm lateral size and 0,31µm thickness were synthesized. The comparison with literature results show that for the first time, our group could synthesize large scale, thin and more transparent GO flakes by simple Hummer’s method using simple dispersed graphite. EDX measurements indicate the formation of layered structure with oxygen containing functional groups. The intensity ratio between D and G peaks in the Raman spectra proves that less defective GO flakes have been synthesized. The solution ability of the synthesized material indicate that high quality GO flakes were synthesized, which make them effective soluble material due to oxygen containing groups formed on the graphene plane during synthesis process.DSC results shows that these flakes are thermally stable till 200°C.  Due to high solubility properties, large scale and transparency they can be very useful in fabrication of high optical transparent nanocompoties for replacement indium tin oxide transparent conductors in solar panels, biomedical applications and microwave absorbers for electromagnetic interference (EMI) environmental protection.

Intermetallic Alloys Ni3Si and Ni3(Si,Ti): Microstructures and Properties

2008 ◽  
Vol 368-372 ◽  
pp. 1143-1145 ◽  
Author(s):  
Ding Fan ◽  
Yao Ning Sun ◽  
Min Zheng ◽  
Jian Bin Zhang ◽  
Yu Feng Zheng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Continuous Wave ◽  
Chemical Compositions ◽  
Intermetallic Alloys ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

Laser cladding experiment was carried out with a 5 kW continuous wave CO2 laser by preplacing Ni75Si25 and Ni78Si13Ti9 powders onto Ni-based superalloy substrate. The microstructure of the specimens was monitored by using optical and scanning electron microscopy. The chemical compositions of the alloys and their phases were obtained using X-ray diffraction and energy dispersive x-ray spectroscopy. The phase transformation temperatures were determined by non-isothermal differential scanning calorimetry tests. The microhardness of the laser cladded sample was measured.

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