Hydrothermal Growth of ZnO Hexagonal Nanocrystals: Effect of Growth Conditions

2012 ◽  
Vol 21 ◽  
pp. 57-63 ◽  
Author(s):  
Sujira Promnimit ◽  
S. Baruah ◽  
U. Lamdu ◽  
Joydeep Dutta
Keyword(s):  
Growth Parameters ◽  
Zno Nanorods ◽  
Average Diameter ◽  
Growth Conditions ◽  
Hydrothermal Route ◽  
Hydrolysis Time ◽  
Aspect Ratios ◽  
Zno Nanocrystals ◽  
Seeding Method ◽  
Wide Range

Hexagonal ZnO nanocrystals were synthesized through a hydrothermal route under mild conditions (growth temperature of 90°C at atmospheric pressure). Pre-synthesized ZnO nanoparticles were used to serve as nucleation sites for the growth of the nanocrystals. The growth of ZnO nanorods was found to be surface independent. The dimensions of the hexagonal ZnO nanocrystals were observed to be dependent on the concentration of the reactants used (sources of Zn2+ and OH-ions), pH of the growth bath and also on the duration of crystal growth. The average diameter and height of the ZnO nanocrystals was found to be directly proportional to the concentration of the reactants as well as hydrolysis time. The orientation of the nanocrystals was found to be dependent upon the seeding method employed. Hexagonal single crystals of a wide range of dimensions and aspect ratios could be successfully synthesized through a control of growth parameters.

Mini droplets to super droplets: evolution of self-assembled Au droplets on GaAs(111)B and (110)

2014 ◽  
Vol 47 (2) ◽  
pp. 505-510 ◽  
Author(s):  
Mao Sui ◽  
Ming-Yu Li ◽  
Eun-Soo Kim ◽  
Jihoon Lee
Keyword(s):  
Growth Parameters ◽  
Average Diameter ◽  
Growth Conditions ◽  
Average Density ◽  
Minor Effect ◽  
Average Height ◽  
Deposition Amount ◽  
Self Assembled ◽  
A Minor ◽  
20 Nm

In this article, the effect of deposition amount on self-assembled Au droplets fabricated on GaAs(111)B and (110) is presented. The investigation is systematically performed by the variation of the Au deposition amount from 2 to 20 nm while fixing the other growth parameters such as annealing temperature and duration to clearly observe the effect. Under identical growth conditions, the self-assembled Au droplets show significantly different size and density depending on the amount of Au deposition:i.e.the average height varies by 436% from 21.8 to 95.5 nm and the average diameter swings by 827% from 52 to 430 nm, showing that the size increase is dominated by the lateral expansion. Meanwhile the average density varies by over two orders of magnitude from 1.24 × 108to 4.48 × 1010 cm−2on GaAs(111)B. With relatively low Au deposition amounts, below 3 nm, round dome-shaped mini Au droplets with high packing density can be fabricated, while super large Au droplets result with higher deposition amounts, above 10 nm, with a density two orders of magnitude lower. It is also found that the surface index has a minor effect on the fabrication of self-assembled Au droplets with the variation of deposition amount. The results are systematically analyzed and discussed in terms of atomic force microscopy and scanning electron microscopy images, line profiles, power spectrums, r.m.s. surface roughness, and size and density plots.

scholarly journals Growth of ZnO nanorods on different substrates using hydrothermal method

2020 ◽  
Vol 16 (2) ◽  
pp. 154-157
Author(s):  
Rina Dewi Mayasari ◽  
Aditya Eka Mulyono ◽  
Masmui Masmui ◽  
Wawas Swathatafrijiah ◽  
Agustanhakri Agustanhakri ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Seed Layer ◽  
Growth Parameters ◽  
Zno Nanorods ◽  
Vertical Direction ◽  
Hexagonal Wurtzite Structure ◽  
Average Diameter ◽  
Sio2 Film ◽  
Acetate Solution ◽  
Au Film

Zinc oxide (ZnO) nanorods have been grown on different substrates, i.e. gold film-coated BK-7 glass (Au-film/BK7), microscope glass slide (MGS), silicon oxide film-coated silicon (SiO2-film/Si), to investigate the effects of different substrates on its material properties. The growth process was started by dipping substrates in zinc acetate solution to fabricate a seed layer, followed by growing the ZnO nanorods in zinc nitrate tetrahydrate solution based on hydrothermal method at 95 °C for 6 hour. In this process, seed layer and ZnO nanorods were annealed at 350 °C for 2 hours. The characterization results using X-ray diffraction and field effect scanning electron microscope showed that ZnO nanorods were successfully grown homogenously and mostly in vertical direction with hexagonal wurtzite structure. The diameter size of ZnO nanorods was significantly influenced by the type of material substrate. ZnO nanorods on Au-film/BK-7 glass have the smallest diameter size of (239±51) nm, while the average diameter size of ZnO nanorods on MGS is of (269±53) nm and ZnO nanorods on SiO2-film/Si have the largest diameter size of (354±80) nm. The effect of substrates on different size of ZnO nanorods may be regarded to the intrinsic thermal conductivity of substrate material. Hence, the synthesis and growth parameters for the different substrates differ from each other and need to be optimized in order to grow ZnO nanostructures

A Nucleation Study of GaN Multifunctional Nanostructures

2004 ◽  
Vol 831 ◽  
Author(s):  
Gupta Shalini ◽  
Kang Hun ◽  
Strassburg Martin ◽  
Asghar Ali ◽  
Senawiratne Jayantha ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Optimal Growth ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Mocvd Growth ◽  
Aspect Ratios ◽  
Nucleation Sites ◽  
Wide Range ◽  
Metal Organic ◽  
Multifunctional Nanostructures

ABSTRACTThis paper reports the Metal Organic Chemical Vapor Deposition (MOCVD) growth of GaN nanostructures. The use of MOCVD allows the direct integration of these nanostructures into pre-existing device technology. The formation of GaN nanostructures grown on AlN epitaxial layers were studied as a function of growth temperature, growth rate, V-III ratio and the amount of deposited material. A wide range of temperatures from 800 °C to 1100 °C and V-III ratios from 30 to 3500 were applied to determine the optimal growth conditions for nucleation studies in a modified production reactor. Small GaN nanostructures with lateral dimensions below 50 nm and low aspect ratios were obtained using relatively low temperatures of 815 °C and extreme metal-rich growth conditions. Island densities up to 1010 cm−2 were achieved using silane as an anti-surfactant to increase the available nucleation sites. Manganese has been incorporated into these nanostructures to enhance the multifunctional ferromagnetic properties of GaMnN.

scholarly journals Facile Hydrothermal Approach to ZnO Nanorods at Mild Temperature

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Yang Jiao ◽  
Yang Liu ◽  
Bosi Yin ◽  
Siwen Zhang ◽  
Fengyu Qu ◽  
...  
Keyword(s):  
Critical Role ◽  
Zno Nanorods ◽  
Photoluminescence Property ◽  
Average Diameter ◽  
Experimental Results ◽  
Hydrothermal Route ◽  
Ultraviolet Emission ◽  
Facile Hydrothermal Route ◽  
Hydrothermal Approach ◽  
Mild Temperature

In this work, ZnO nanorods are obtained through a facile hydrothermal route. The structure and morphology of the resultant products are characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The experimental results indicated that the as-synthesized ZnO nanorods have an average diameter of approximate 100 nm. A possible growth mechanism for ZnO nanorods was proposed based on the experimental results and found that Zn powder plays a critical role for the morphology of the products. Room temperature photoluminescence property of ZnO nanorods shows an ultraviolet emission peak at 390 nm.

Facile Synthesis of Phosphogypsum-Based Whiskers by Low Temperature Hydrothermal Route with CTAB Addition

2016 ◽  
Vol 852 ◽  
pp. 1450-1454 ◽  
Author(s):  
Lin Lin Zhuang ◽  
Ming Ding ◽  
Cheng Liang Han
Keyword(s):  
Low Temperature ◽  
Rough Surface ◽  
Hydrothermal Process ◽  
Average Diameter ◽  
Selective Growth ◽  
Hexadecyltrimethylammonium Bromide ◽  
Facile Synthesis ◽  
Hydrothermal Route ◽  
Aspect Ratios

CaSO4·0.5H2O whiskers were successfully synthesized by hydrothermal process, in which phosphogypsum (PG) was employed as precursors. The effect of the hexadecyltrimethylammonium bromide (CTAB) on the formation of phosphogypsum-based CaSO4·0.5H2O whiskers was investigated in details. Results indicated that the average diameter and length of as-prepared CaSO4·0.5H2O whiskers with rough surface were about 0.15-2.5μm and 10-50 μm, respectively. The added CTAB templates would effectively guided the selective growth of CaSO4·0.5H2O particles which led to formation of whiskers with high aspect ratios.

Study of MBE ZnSe Growth Using Rheed Oscillations

1989 ◽  
Vol 145 ◽  
Author(s):  
Francoise S. Turco ◽  
M.C. Tamargo
Keyword(s):  
Growth Rate ◽  
Quantitative Study ◽  
Growth Parameters ◽  
Growth Conditions ◽  
High Energy ◽  
Growth Mechanisms ◽  
Mbe Growth ◽  
Wide Range ◽  
Main Growth

AbstractReflection high energy electron diffraction (RHEED) intensity oscillations are often used to investigate in situ the growth of III-V materials by molecular beam epitaxy (MBE). In this work, we have used RHEED oscillations to perform a quantitative study of the growth mechanisms of ZnSe, a II-VI semiconductor.Our experiments illustrate that the RHEED pattern of ZnSe is far less intense than that of III-V materials grown by MBE, and no specular spot is observed over a wide range of growth conditions. We have, however, been able to record up to 25 oscillations allowing a quantitative study of the growth of ZnSe by MBE. Thus we have used RHEED oscillations to make an in situ systematic study of the influence of the three main growth parameters (substrate temperature and Zn or Se impinging fluxes) on the ZnSe growth rate. We observed that the variation of the ZnSe growth rate is due to a non unity sticking coefficient of both Zn and Se species at the interface in the standard growth conditions used. Our observations can be described using a thermodynamic model and enable us to control the desired growth conditions. Our work demonstrates the utility of RHEED oscillations to understand the MBE growth mechanisms of II-VI compounds.

scholarly journals Electrochromic Performance and Capacitor Performance of α-MoO3 Nanorods Fabricated by a One-Step Procedure

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 783
Author(s):  
Ying Duan ◽  
Chen Wang ◽  
Jian Hao ◽  
Yang Jiao ◽  
Yanchao Xu ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Average Diameter ◽  
Fast Response ◽  
Cycle Stability ◽  
Electrochromic Devices ◽  
Step Procedure ◽  
One Step ◽  
Supercapacitor Performance ◽  
First Time ◽  
Prepared Nanorods

In this paper, we propose for the first time the synthesis of α-MoO3 nanorods in a one-step procedure at mild temperatures. By changing the growth parameters, the microstructure and controllable morphology of the resulting products can be customized. The average diameter of the as-prepared nanorods is about 200 nm. The electrochromic and capacitance properties of the synthesized products were studied. The results show that the electrochromic properties of α-MoO3 nanorods at 550 nm have 67% high transmission contrast, good cycle stability and fast response time. The MoO3 nanorods also exhibit a stable supercapacitor performance with 98.5% capacitance retention after 10,000 cycles. Although current density varies sequentially, the nanostructure always exhibits a stable capacitor to maintain 100%. These results indicate the as-prepared MoO3 nanorods may be good candidates for applications in electrochromic devices and supercapacitors.

Glycans in scaffold design in tissue reconstruction

2021 ◽  
pp. 088391152199784
Author(s):  
Nipun Jain ◽  
Shashi Singh
Keyword(s):  
Cell Attachment ◽  
Low Cost ◽  
Growth Conditions ◽  
Downstream Signaling ◽  
Cell Carrier ◽  
Wide Range ◽  
Proliferation And Differentiation ◽  
Different Types ◽  
Tissue Reconstruction ◽  
A Cell

Development of an artificial tissue by tissue engineering is witnessed to be one of the long lasting clarified solutions for the damaged tissue function restoration. To accomplish this, a scaffold is designed as a cell carrier in which the extracellular matrix (ECM) performs a prominent task of controlling the inoculated cell’s destiny. ECM composition, topography and mechanical properties lead to different types of interactions between cells and ECM components that trigger an assortment of cellular reactions via diverse sensing mechanisms and downstream signaling pathways. The polysaccharides in the form of proteoglycans and glycoproteins yield better outcomes when included in the designed matrices. Glycosaminoglycan (GAG) chains present on proteoglycans show a wide range of operations such as sequestering of critical effector morphogens which encourage proficient nutrient contribution toward the growing stem cells for their development and endurance. In this review we discuss how the glycosylation aspects are of considerable importance in everyday housekeeping functions of a cell especially when placed in a controlled environment under ideal growth conditions. Hydrogels made from these GAG chains have been used extensively as a resorbable material that mimics the natural ECM functions for an efficient control over cell attachment, permeability, viability, proliferation, and differentiation processes. Also the incorporation of non-mammalian polysaccharides can elicit specific receptor responses which authorize the creation of numerous vigorous frameworks while prolonging the low cost and immunogenicity of the substance.

scholarly journals Strength Analysis of Alternative Airframe Layouts of Regional Aircraft on the Basis of Automated Parametrical Models

Aerospace ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 80
Author(s):  
Dmitry V. Vedernikov ◽  
Alexander N. Shanygin ◽  
Yury S. Mirgorodsky ◽  
Mikhail D. Levchenkov
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
High Performance ◽  
Strength Analysis ◽  
Labor Input ◽  
Aerodynamic Loading ◽  
Aspect Ratios ◽  
Wide Range ◽  
Parametrical Design

This publication presents the results of complex parametrical strength investigations of typical wings for regional aircrafts obtained by means of the new version of the four-level algorithm (FLA) with the modified module responsible for the analysis of aerodynamic loading. This version of FLA, as well as a base one, is focused on significant decreasing time and labor input of a complex strength analysis of airframes by using simultaneously different principles of decomposition. The base version includes four-level decomposition of airframe and decomposition of strength tasks. The new one realizes additional decomposition of alternative variants of load cases during the process of determination of critical load cases. Such an algorithm is very suitable for strength analysis and designing airframes of regional aircrafts having a wide range of aerodynamic concepts. Results of validation of the new version of FLA for a high-aspect-ratio wing obtained in this work confirmed high performance of the algorithm in decreasing time and labor input of strength analysis of airframes at the preliminary stages of designing. During parametrical design investigation, some interesting results for strut-braced wings having high aspect ratios were obtained.

scholarly journals Xanthones Production in Gentiana dinarica Beck Hairy Root Cultures Grown in Simple Bioreactors

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1610
Author(s):  
Branka Vinterhalter ◽  
Nevena Banjac ◽  
Dragan Vinterhalter ◽  
Dijana Krstić-Milošević
Keyword(s):  
Hairy Root ◽  
Large Scale ◽  
Bubble Column ◽  
Growth Parameters ◽  
Growth Index ◽  
Dry Weight ◽  
Growth Conditions ◽  
Good Growth ◽  
Gentiana Dinarica ◽  
Hairy Root Clones

The hairy root clones of Gentiana dinarica cl-B, cl-D, cl-3, and cl-14 were cultivated in parallel in diverse simple bioreactors, including temporary immersion systems RITA® (TIS RITA®), bubble column bioreactors (BCB), and Erlenmeyer flasks (EF), and evaluated for biomass production and xanthone content. The obtained results showed that TIS RITA® and BCB containing ½ MS medium with 4% sucrose provided equally good growth conditions in which the majority of the clones displayed the higher percentage of dry matter (DM%), and xanthones norswertianin-1-O-primeveroside (nor-1-O-prim) and norswertianin production than those cultivated in EF. Thin and well branched hairy root clone cl-B grown in BCB for 7 weeks was superior regarding all growth parameters tested, including growth index (19.97), dry weight (2.88 g), and DM% (25.70%) compared to all other clones. Cl-B cultured in TIS RITA® contained the highest amount of nor-1-O-prim (56.82 mg per vessel). In BCB with constant aeration, cl-B accumulated the highest norswertianin content reaching 18.08 mg/vessel. The optimized conditions for cultivation of selected G. dinarica hairy root clones in highly aerated TIS RITA® and BCB systems contribute to the development of bioreactor technology designed for the large scale commercial production of xanthones nor-1-O-prim and norswertianin.

Sign in / Sign up

Export Citation Format

Share Document