Novel Methods for Preparation and Surface Treatment of Nano-CaCO3

2013 ◽  
Vol 750-752 ◽  
pp. 336-339
Author(s):  
Fa Chao Wu ◽  
Teng Fei Shen

In this work, CaCO3 nanoparticles have been synthesized via heat-treatment of a new precursor. Effect of calcinations temperature on particle size has been investigated. The products were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). nanoCaCO3 was modified using chloroform as solvent and fatty acid as modifier atroom temperature. The advantage of this modification is that it can be proceed at room temperature and it can reduce energy consumption.

2013 ◽  
Vol 774-776 ◽  
pp. 646-649
Author(s):  
Teng Fei Shen ◽  
Ying Juan Sun

In this work, nanoAlumina particles (nanoAl2O3) have been synthesized via solid state reaction. Effect of quantity of surfactant on particle size has been investigated. nanoAl2O3 was modified using chloroform as solvent and fatty acid as modifier at room temperature. The advantage of this modification is that it can be proceed at room temperature and it can reduce energy consumption. The products were characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).


2009 ◽  
Vol 81 (12) ◽  
pp. 2317-2325 ◽  
Author(s):  
Wei-De Zhang ◽  
Jin Chen

Strongly bonded arrays of vertically aligned, multi-walled carbon nanotubes (MWNTs) have been successfully grown on Ta foils, and provide a convenient basis for fabricating electrodes with high conductivity and stability. The MWNT arrays were further coated by nanostructured MnO2 through reacting with KMnO4 solution at room temperature. The morphology of the MnO2/MWNT nanocomposite was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the MnO2 is a beehive-like nanostructure that is homogeneously and densely coated on the surface of the MWNTs. The capacitance of the MWNT electrode was significantly increased from 0.14 to 6.81 mF cm–2 after being modified with nanostructured MnO2, that is, the mass-specific capacitance of the bare and MnO2-modified MWNTs was about 33 and 446 F g–1, respectively. The MnO2/MWNT nanocomposite on Ta foils could be potential for developing a supercapacitor.


2003 ◽  
Vol 792 ◽  
Author(s):  
V. Shutthanandan ◽  
Y. Zhang ◽  
C. M. Wang ◽  
J. S. Young ◽  
L. Saraf ◽  
...  

ABSTRACTNucleation of gold nanoclusters in TiO2(110) single crystal using ion implantation and subsequent annealing were studied by Rutherford backscattering spectrometry /channeling (RBS/C), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Approximately 1000 Au2+/nm2 were implanted at room temperature in TiO2(110) substrates. TEM and SEM measurements reveal that rounded nanoclusters were formed during the implantation. In contrast, subsequent annealing in air for 10 hours at 1275 K promoted the formation of faceted (rectangular shaped) Au nanostructures in TiO2. RBS channeling measurements further reveled that Au atoms randomly occupied the host TiO2 lattice during the implantation. However, it appears that some Au atoms moved to the Ti lattice positions after annealing.


2011 ◽  
Vol 117-119 ◽  
pp. 679-682
Author(s):  
Bing Bing Li ◽  
Liang Wang ◽  
De Sun

Fumed Silica was modified with hexamethyldisiazane (HMDZ, modifier) and dimethyldiethoxysilane (DMDEOS, co-modifier) by grafting method. The structure of organo-functionnalized nanoparticles was characterized by fourier transform infrared spectrum (FT-IR) and transmission electron microscopy (TEM). Functional nanosilica-filled polydimethylsiloxane(PDMS) composites membrane were prepared. Scanning electron microscopy (SEM) observations of composites revealed good dispersion of the silica nanoparticles and the pervaporation performance of the filled PDMS membranes is better than that of the unfilled PDMS membranes.


2014 ◽  
Vol 1642 ◽  
Author(s):  
E. Hatzikraniotis ◽  
G.S. Polymeris ◽  
C.B. Lioutas ◽  
A. Burkov ◽  
E-C. Stefanaki ◽  
...  

ABSTRACTIn the present work, a comparative study is attempted, dealing with the influence of the grain size distribution on the microstructure and the free carrier concentration in Mg2SnXSi1-X (x=0.2) ternary compounds doped with Sb. Structural in-homogeneities were monitored by using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) as well as Fourier transform infrared spectroscopy (FTIR) in the reflectivity mode.


2012 ◽  
Vol 538-541 ◽  
pp. 1053-1056
Author(s):  
Yang Zheng Zeng ◽  
Kai Ming Wu ◽  
Feng Hu ◽  
Hua Zheng

The effect of partitioning process of quenching-partitioning-tempering (Q-P-T) process on hardness and microstructure were investigated. The 1-step Q-P-T and 2-step Q-P-T heat treatment were designed and carried out. The microstructure and carbides were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) patterns. Results showed that compared with 1-step Q-P-T heat treatment, more amount of retained austenite was obtained by 2-step Q-P-T heat treatment, however, the carbides were bigger in size and the hardness was lower.


2011 ◽  
Vol 217-218 ◽  
pp. 75-78 ◽  
Author(s):  
Jian Xiang Yu ◽  
Tai Qi Liu

a novel fibrous catalyst containing palladium nano-particles was produced via electrospinning technique. The fibrous catalyst was characterized by scanning electron microscopy and transmission electron microscopy respectively, the results showed that the diameter of fiber was about 200 nm and the palladium (Pd) particles were in the range of 30~40 nm. The catalyst was tested in hydrogenations of α-olefins, cyclohexene and nitrobenzol in ethanol at room temperature under 1 atmosphere hydrogen. The results showed that the titled catalyst had high activity in the hydrogenations of α-olefins, cyclohexene and nitrobenzol.


BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7817-7829
Author(s):  
Sabah Ashrafi Birgani ◽  
Mohammad Talaeipour ◽  
Amir Hooman Hemmasi ◽  
Behzad Bazyar ◽  
Kambiz Larijani

The cellulose used in this study was prepared from bleached soda bagasse obtained from the Pars paper factory. To prepare nanocellulose, the sample was subjected to alkaline pretreatment and then acid hydrolysis using 54% sulfuric acid at several temperatures (35, 50, 60, and 65 °C) and different times (30, 60, 90, and 120 min). Then, they were prepared using a centrifuge, dialysis bag, ultrasound, and freezer, respectively. The produced nanocellulose was characterized by transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). According to the results, temperatures of 50 and 90 °C were selected for the preparation of nanocellulose. The crystallization index of the hydrolyzed pulp and produced nanocellulose was 53 and 61%, respectively. The produced nanocellulose had a fibrillar shape.


2014 ◽  
Vol 887-888 ◽  
pp. 139-142
Author(s):  
Yang Rong Yao ◽  
Ying Zheng ◽  
Xu Chun Song

In the present paper, the γ-Fe2O3 nanoparticles have been successfully synthesized by the co-precipitation process and followed by calcination. The X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to characterize the as prepared nanoparticles. The results show that the phase structure of the nanoparticles is γ-Fe2O3 with the particle size ranging from 40 to 50 nm. The catalytic activity of the γ-Fe2O3 was investigated by decomposing the phenol in liquid phase. The results showed that γ-Fe2O3 has the highest catlytic activity.


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