scholarly journals Manganese Dioxide Nanowires of Tunable Dimensions Synthesized via a Facile Hydrothermal Route

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Ying Ying Kong ◽  
Suh Cem Pang ◽  
Suk Fun Chin
Keyword(s):  
Manganese Dioxide ◽  
Reaction Temperature ◽  
Homogeneous Solution ◽  
Hydrothermal Route ◽  
Initial Concentration ◽  
Aspect Ratios ◽  
Synthesis Parameters ◽  
Facile Hydrothermal Route ◽  
Mean Diameter ◽  
The Mean

Manganese dioxide (MnO2) nanowires of tunable dimensions were successfully synthesized via the facile water-bathing hydrothermal route. Homogeneous solution mixtures of KMnO4and MnSO4of varying compositions were being aged in a thermostated water bath under controlled conditions. The dimensional aspect ratios of MnO2nanowires formed were readily modulated by varying synthesis parameters such as the initial concentration of chemical precursors, reaction temperature, and aging duration. At fixed initial precursor concentrations, the mean diameter of MnO2nanowires decreased slightly from 57 nm to 53 nm with increased reaction temperature from 60°C to 90°C. The mean diameter of MnO2nanowires decreased linearly within the range of 104 nm and 35 nm as the initial concentration of both precursors was increased in turn within the range of 10 mmol and 40 mmol at fixed aging temperature and duration. Upon aging for 2 to 24 hours at 80°C, the mean diameter and length of MnO2nanowires were observed to vary within the range of 33–55 nm and 0.69–2.68 μm, respectively, which corresponded to the dimensional aspect ratio range of 21 to 49. Henceforth, MnO2nanowires of tunable dimensions could be synthesized through optimally controlled synthesis parameters.

scholarly journals Controlled Synthesis of Manganese Dioxide Nanostructures via a Facile Hydrothermal Route

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Suh Cem Pang ◽  
Suk Fun Chin ◽  
Chian Ye Ling
Keyword(s):  
Phase Transformation ◽  
Manganese Dioxide ◽  
Structural Evolution ◽  
Controlled Synthesis ◽  
Hydrothermal Route ◽  
Hydrothermal Aging ◽  
Synthesis Parameters ◽  
Facile Hydrothermal Route ◽  
Lower Temperature ◽  
And Control

Manganese dioxide nanostructures with controllable morphological structures and crystalline phases were synthesized via a facile hydrothermal route at low temperatures without using any templates or surfactants. Both the aging duration and aging temperatures were the main synthesis parameters used to influence and control the rate of morphological and structural evolution of MnO2nanostructures. MnO2nanostructures comprise of spherical nanoparticulate agglomerates and highly amorphous in nature were formed at lower temperature and/or short aging duration. In contrast, MnO2nanostructures of sea-urchin-like and nanorods-like morphologies and nanocrystalline in nature were prepared at the combined higher aging temperatures and longer aging durations. These nanostructures underwent notable phase transformation from δ-MnO2to α-MnO2upon prolonged hydrothermal aging duration and exhibited accelerated rate of phase transformation at higher aging temperature.

scholarly journals Optimizing Delivery Characteristics of Curcumin as a Model Drug via Tailoring Mean Diameter Ranges of Cellulose Beads

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Lee Ken Voon ◽  
Suh Cem Pang ◽  
Suk Fun Chin
Keyword(s):  
Reaction Temperature ◽  
Surfactant Concentration ◽  
Regenerated Cellulose ◽  
Release Kinetic ◽  
Mean Diameter ◽  
The Mean ◽  
Model Drug ◽  
Fabrication Parameters ◽  
Cellulose Concentration

Spherical cellulose beads with tailored mean diameter between micrometer (20–80 μm) and nanometer (40–200 nm) ranges were fabricated from regenerated cellulose of paper wastes via water-in-oil (W/O) microemulsion and nanoprecipitation processes, respectively. The mean diameter ranges of cellulose beads were precisely controlled via modulating fabrication parameters such as stirring speed, surfactant concentration, cellulose concentration, and reaction temperature. By tailoring their mean diameter ranges and using curcumin as a model drug, cellulose beads with enhanced loading capacities and optimized release kinetic profiles of curcumin were fabricated.

scholarly journals Morphological changes of ZnO nanostructures upon addition of Trisodium Citrate (Na3C6H5O7) at different reaction temperatures

2021 ◽  
Vol 5 (1) ◽  
pp. 18-22
Author(s):  
Aqilah Kamaruzaman ◽  
Nurul Akmal Che Lah
Keyword(s):  
Size Distribution ◽  
Reaction Temperature ◽  
Morphological Changes ◽  
Chemical Properties ◽  
Trisodium Citrate ◽  
Zno Nanostructure ◽  
Mean Diameter ◽  
Mean Size ◽  
The Mean ◽  
Physical And Chemical

Due to its interesting physical and chemical properties, zinc oxide (ZnO) is considered one of the front runners of numerous metal oxide semiconductors. In this paper, ZnO nanostructure are synthesised by hydrothermal method with trisodium citrate (TC) as the emulsfying agent. The mean diameetr of ZnO nanostructure are observed with increment of reaction temperature. The mean size results into no change to mean diameter upon increment of reaction temperature but the cumulative frequencies of size distribution showing ZnO nanostructure synthesised in higher temperature to have narrower size distribution. The addition of TC also results into much smaller ZnO nanostructure with mean diameter 8nm

Non-isothermal crystallization behavior of spinel crystals in FeO-SiO2-TiO2-V2O3-Cr2O3 slag

2018 ◽  
Vol 116 (1) ◽  
pp. 110
Author(s):  
Lixiong Shao ◽  
Jiang Diao ◽  
Wang Zhou ◽  
Tao Zhang ◽  
Bing Xie
Keyword(s):  
Cooling Rate ◽  
Crystallization Behavior ◽  
Crystal Size ◽  
Growth Mechanisms ◽  
Vanadium Slag ◽  
Growth Behaviour ◽  
Temperature Range ◽  
Chromium Spinel ◽  
Mean Diameter ◽  
The Mean

The growth behaviour of spinel crystals in vanadium slag with high Cr2O3 content was investigated and clarified by statistical analyses based on the Crystal Size Distribution (CSD) theory. The results indicate that low cooling rate and Cr2O3 content benefit the growth of spinel crystals. The chromium spinel crystals firstly precipitated and then acted as the heterogeneous nuclei of vanadium and titanium spinel crystals. The growth mechanisms of the spinel crystals at the cooling rate of 5 K/min consist two regimes: firstly, nucleation control in the temperature range of 1873 to 1773 K, in which the shapes of CSD curves are asymptotic; secondly, surface and supply control within the temperature range of 1773 to 1473 K, in which the shapes of CSD curves are lognormal. The mean diameter of spinel crystals increases from 3.97 to 52.21 µm with the decrease of temperature from 1873 to 1473 K.

scholarly journals Bark proportion of Scots pine industrial wood

2021 ◽  
Author(s):  
Ferréol Berendt ◽  
Erik Pegel ◽  
Lubomir Blasko ◽  
Tobias Cremer
Keyword(s):  
Supply Chain ◽  
Scots Pine ◽  
Bark Thickness ◽  
Wood Supply ◽  
Volume Proportion ◽  
Bark Damage ◽  
Mass Proportion ◽  
Mean Diameter ◽  
The Mean

AbstractBark characteristics are not only used in the forest-wood supply chain, for example to calculate standing volumes, but also to transform wood volumes and masses. In this study, bark thickness, bark volume and bark mass were analyzed on the basis of 150 Scots pine discs, with a mean diameter of 13 cm. The mean double bark thickness was 3.02 mm, the mean bark volume proportion was 5.6% and mean bark mass proportion was 3.3%. Bark proportions were significantly affected by the log-specific variables ‘diameter over bark’, ‘proportion of bark damage’ and ‘double bark thickness’.

PEG-Assisted Hydrothermal Synthesis and Photocatalytic Activity of Bi2Fe4O9 Crystallites

2011 ◽  
Vol 1292 ◽  
Author(s):  
Dengrong Cai ◽  
Jianmin Li ◽  
Shundong Bu ◽  
Shengwen Yu ◽  
Dengren Jin ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectrum ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Peg 400 ◽  
Transmission Electron ◽  
Light Region ◽  
Facile Hydrothermal Route ◽  
Degradation Ratio

ABSTRACTA facile hydrothermal route assisted by polyethylene glycol (PEG) 400 was utilized to synthesize single-phase Bi2Fe4O9 crystallites. X-ray diffraction results showed the products with PEG 400 of 30 g/L exhibited a preferred growth along the (001) plane. Transmission electron microscopy indicated that the morphology of the as-prepared Bi2Fe4O9 crystallites with PEG 400 were plake-like and rod-like. Strong absorption in visible-light region of the products was characterized by UV-vis diffuse reflectance spectrum (UV-DRS). The photocatalytic activity of Bi2Fe4O9 crystallites was evaluated on degradation of methyl orange (MO) under visible light irradiation. For 3 h irradiation, the degradation ratio was increased to 93% with the aid of a small amount of H2O2. The analysis of FT-IR spectra proved that the Bi2Fe4O9 catalysts were remained stable after the photocalytic reactions.

Improved hydrothermal synthesis of MoS2 sheathed carbon nanotubes

2012 ◽  
Vol 66 (12) ◽  
Author(s):  
Jaciel Robles-Nuñez ◽  
Fernando Chiñas-Castillo ◽  
Manuel Sanchez-Rubio ◽  
Javier Lara-Romero ◽  
Rafael Huirache-Acuña ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Hydrothermal Synthesis ◽  
Reaction Temperature ◽  
High Yield ◽  
Hydrothermal Route ◽  
Simple Process ◽  
Toxic Materials ◽  
Resultant Material ◽  
Full Body

AbstractMoS2 sheathed carbon nanotubes have been successfully synthesized using a hydrothermal route under controlled conditions. The resultant material was studied by XRD, EDS, HRTEM, and Raman spectroscopy. Advantages of the preparation presented here compared to other methods are: a) lower reaction temperature, b) high yield of sheathed nanotubes including ends and full body, c) simple process with non-toxic materials, and d) no damage inflicted to nanotubes.

CONTROLLABLE CHEMICAL VAPOR DEPOSITION SYNTHESIS OF SINGLE-WALL CARBON NANOTUBES USING MIST FLOW METHOD

NANO ◽  
2012 ◽  
Vol 07 (06) ◽  
pp. 1250045 ◽  
Author(s):  
YUN SUN ◽  
RYO KITAURA ◽  
TAKUYA NAKAYAMA ◽  
YASUMITSU MIYATA ◽  
HISANORI SHINOHARA
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Single Wall Carbon Nanotubes ◽  
Flow Method ◽  
Mist Flow ◽  
Mean Diameter ◽  
The Mean

The influences of synthesis parameters on the mean diameter and diameter distribution of as-grown single-wall carbon nanotubes (SWCNTs) with chemical vapor deposition (CVD) using the mist flow method have been investigated in detail with Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We found that CVD reaction temperature and flow rate play an essential role in controlling the mean diameter and the quality of as-grown SWCNTs. Furthermore, we found that the carbon supply kinetics can be a dominant factor to determine the diameter of as-grown SWCNTs in the present mist flow method. Under a different combination of various parameters, the mean diameter of SWCNTs can be varied from 0.9 nm to 1.5 nm controllably.

Effect of hydrothermal dwell time on the diameter-controlled synthesis and magnetic property of MnO2 nanorods

2014 ◽  
Vol 28 (06) ◽  
pp. 1450045 ◽  
Author(s):  
Arbab Mohammad Toufiq ◽  
Fengping Wang ◽  
Qurat-ul-Ain Javed ◽  
Yan Li
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Dwell Time ◽  
Hydrothermal Reaction ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Hydrothermal Reaction Time

In this paper, single crystalline 1D tetragonal MnO 2 pen-type nanorods were synthesized by varying the dwell time through a facile hydrothermal route at a reaction temperature of 250°C. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies showed that the diameter of MnO 2 nanorods decreases from 460 nm to 250 nm with the increase in hydrothermal reaction time from 5 h to 15 h. Field-emission scanning electron microscopy (FESEM) and TEM studies revealed the evolution of improved surface morphology of MnO 2 nanorods that are prepared with longer hydrothermal reaction time. The magnetic properties of the products were evaluated using vibrating sample magnetometer (VSM) at room temperature, which showed that the as-prepared samples exhibit weak ferromagnetic behavior. The effect of diameter on the magnetization values was observed and discussed in detail.

Initial Clinical Experience with Percutaneous Atherectomy in the Infragenicular Arteries

2003 ◽  
Vol 10 (5) ◽  
pp. 987-993 ◽  
Author(s):  
Thomas Zeller ◽  
Ulrich Frank ◽  
Karlheinz Bürgelin ◽  
Uwe Schwarzwälder ◽  
Peter-Christian Flügel ◽  
...  
Keyword(s):  
Balloon Angioplasty ◽  
Ankle Brachial Index ◽  
Peroneal Artery ◽  
Lesion Length ◽  
Anterior Tibial Artery ◽  
Tibial Artery ◽  
Below The Knee ◽  
Directional Atherectomy ◽  
Mean Diameter ◽  
The Mean

Purpose: To evaluate the efficacy and safety of a new atherectomy device for the treatment of infragenicular lesions in arteries with a reference diameter of at least 2.5 mm. Methods: Twenty-seven below-the-knee lesions in 17 patients (12 men; mean age 69±12 years) with chronic peripheral arterial occlusive disease were treated with directional atherectomy. The target lesion was in the popliteal artery (segment 3) in 2 (7%) cases, the tibioperoneal trunk in 12 (44%), the peroneal artery in 8 (30%), the anterior tibial artery in 2 (7%), and the posterior tibial artery in 3 (11%). Six (22%) of the lesions were in-stent stenoses. The mean diameter stenosis was 87%±9%, and the mean lesion length was 34±24 mm. Results: All but 2 (7%) of the lesions could be treated successfully (residual stenosis <30%) with the atherectomy catheter (93% technical success) using an average of 5±2 (range 1–10) passes of the device. Six lesions (22%) were treated after predilation and 21 (78%) with primary atherectomy. In 8 (30%) lesions, additional balloon angioplasty was performed. The 2 failures were in heavily calcified lesions through which the device could not pass despite predilation. The mean diameter stenosis after atherectomy was 14%±22% (range 0%–90%); after additional balloon angioplasty, the mean residual stenoses reduced to 12%±21% (range 0%–100%). One (6%) of the 2 patients who failed atherectomy sustained a thrombotic occlusion of the target vessel. This complication was treated successfully with local lysis, but the vessel reoccluded 3 days later; a stent was implanted. The mean ankle-brachial index increased from 0.50±0.27 to 0.86±0.40 before discharge. Conclusions: Below-the-knee native vessel lesions and in-stent restenoses with a diameter of at least 2.5 mm can be treated successfully and safely with this new atherectomy catheter. Additional balloon angioplasty was necessary in only a few cases.

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