scholarly journals Effect of Conductivity of the Aqueous Solution on the Size of Printable Nanoparticle

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Mi-Hyun Oh ◽  
Nam-Soo Kim ◽  
Sun-Mee Kang

Direct writing technology using nano/microsize particles in aqueous solution is currently one of the leading candidates to bring a substantial advancement to the technical arena. However, little is known about an effect of conductivity of the solution including metal ions on nanoparticle size for the direct writing technology. It is believed that conductivity of solution can influence the size of particles in reducing environmental of aqueous solutions. In this study parameters which affect electric conductivity in solution were characterized by changing concentration of copper ion, concentration of surfactants, and anion of metal compounds. The mobility of ion in aqueous media with respect to copper ion concentration was the most pronounced factor to control the size of created copper nanometals in water. However, due to the high reactivity on large surface area, the nanocopper metal was oxidized in water. The electric conductivity varied in the range of 7 to 360 mS/cm when Cu(NO3)2⋅3H2O dissolved in water from 0.03–3.0 mol/dm3. In this condition, the size of nano particles can vary from 10 to 500 nm. Various concentrations of surfactants and two anion Cu compounds used to vary the conductivity of the solution to verify the effect of electric conductivity of solution on the particle size. Decreasing the conductivity had a corresponding effect on the particle size. The electric conductivity was decreased from 67 to 56 mS/cm by adding surfactant from 0.1 to 0.5 mol/dm3consequently, the particle sizes were decreased from 89 to 21 nm. Copper nitrate and copper chloride were used to verify the anion effect on electrical conductivity and particle sizes. This effect was not dependent on the kind of ions chosen to change the conductivity. However, when Cu(NO3)2⋅3H2O was used, the size of the particles was 89 nm, while it was 91 nm when CuCl2⋅2H2O was used.

2008 ◽  
Vol 5 (4) ◽  
pp. 761-769 ◽  
Author(s):  
S. Madhavakrishnan ◽  
K. Manickavasagam ◽  
K. Rasappan ◽  
P. S. Syed Shabudeen ◽  
R. Venkatesh ◽  
...  

Activated carbon prepared from Ricinus communis Pericarp was used to remove Ni(II) from aqueous solution by adsorption. Batch mode adsorption experiments are carried out by varying contact time, metal-ion concentration, carbon concentration and pH to assess kinetic and equilibrium parameters. The adsorption data were modeled by using both Langmuir and Freundlich classical adsorption isotherms. The adsorption capacity (Qo) calculated from the Langmuir isotherm was 31.15 mg/g of activated carbon at initial pH of 5.0±0.2 for the particle size 125-250 µm.


Author(s):  
F. U. Okwunodulu ◽  
H. O. Chukwuemeka-Okorie ◽  
N. M. Mgbemena ◽  
J. B. I. Kalu

The removal of Cr6+ from aqueous solution using unmodified and hydrochloric modified African nutmeg pod was studied. The effects of particle size, pH and initial metal ions concentration adsorbed were investigated. The amount of metal ion adsorbed increased as the initial metal ion concentration increased and also decreased at low pH of 2 for both modified and unmodified African nutmeg pod.  400 µm and 250 µm were the optimum particle sizes for both modified and unmodified African nutmeg pod respectively, values given as 75.8 mg/g for the modified and 93.39 mg/g for the unmodified. Generally, it was observed that the unmodified African nutmeg pod showed greater adsorption capacity than the modified African nutmeg pod. The equilibrium experimental data were examined via Langmuir and Freundlich isotherm models.  Freundlich isotherm model gave the best fit for the data in both unmodified and modified African nutmeg pod based on the correlation coefficients (R2 values) gotten. The results of the study showed that the African nutmeg pod is efficient for the removal of Cr6+ from aqueous solutions especially when unmodified.


Author(s):  
Uma Sankar Behera ◽  
Prakash Chandra Mishra ◽  
G. B. Radhika

Abstract The conventional method of water treatment using activated carbon from several sources has been focused extensively since the last two decades. However, rare attention has been noticed on natural adsorbents such as plant leaves. Therefore, the Psidium guajava (Guava) leaf has been investigated to understand it's adsorption efficacy for Arsenic (III) [As(III)] in this study. The effect of process variables, e.g., pH, concentration of metal ion, adsorbent's particle size, and dosages, are evaluated. Experiments are carried out in batch mode, and the individual and combined parameter's impact on adsorption have been discussed. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) is used to characterize the adsorbent's surface. Freundlich and Langmuir's isotherms are used for adsorption equilibrium study. The adsorption parameters are optimized by establishing a regression correlation using central composite design (CCD) of response surface methodology (RSM). The analysis of variance (ANOVA) suggests a high regression coefficient (R2 = 0.9249) for the removal of As(III). Particle size of 0.39 mm; adsorbent's height of 10 cm; metal ion concentration of 30 ppm, and pH 6 are optimized to remove 90.88% As(III) from aqueous solution. HCl is evaluated as a potential solvent for desorption of arsenic from desorption study.


Author(s):  
Olaniyi K Yusuff ◽  
Abdulrahman A. Mukadam ◽  
Adenike M.o Abdulraheem ◽  
Aanuoluwapo Akerele

The biosorption of Cr (III) ions from aqueous solutions by groundnut husk, a low-cost biosorbent was studied on a laboratory scale batch experiments. The effects of pH, contact time, particle size, biosorbent dosage and temperature on the adsorption of Cr (III) ions were investigated. Determination of Chromium ion concentration in solution was done using Atomic Absorption Spectrophotometer (AAS). The results show that the removal mechanism is predominantly by chemisorption and it is dependent on the physical and chemical characteristics of the biosorbent material. From the initial concentration of 0.5 mM, optimum Cr (III) ions removal was obtained at pH of 4, particle size of 0.15 nm, contact time of 180 minutes and biosorbent dosage of 50 mg, with the highest biosorption efficiency of 81.15 %. The biosorption process was best described by the BET adsorption isotherm with R2 value 0.9814 indicating multiplayer adsorption. Analysis of the experimental data revealed that the biosorption of Cr (III) ions from aqueous solution by groundnut husk is a spontaneous process with a ?Go value of -24.38 kJmol-1 at 298 K and follow the pseudo second order kinetics with a rate constant of 0.0151 min-1. The results indicate that groundnut husk can be employed as a low cost alternative to commercial adsorbents in the removal of Cr (III) ions from wastewater.


2018 ◽  
Vol 37 ◽  
pp. 02005
Author(s):  
L. Kadiri ◽  
A. Lebkiri ◽  
E.H. Rifi ◽  
A. Ouass ◽  
Y. Essaadaoui ◽  
...  

The adsorption of copper ions Cu2+ by Coriandrum Sativum seeds (CSS) from aqueous solution was studied in order to highlight the importance of coriander seeds as a potential tool in the treatment of wastewaters containing heavy metals. The kinetic studies of adsorption of Cu (II) were discussed using the spectroscopic technique “Inducting Coupled Plasma” (ICP). The effects of initial copper ion concentration and contact time were determined. All results show that coriander seeds have, over their culinary and medicinal benefits, a significant adsorbent power of copper ions.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Kyung-Deok Jang ◽  
Ada Ortega ◽  
Justin Ucol ◽  
Hao Du ◽  
Nam-Soo Kim

Copper nanoparticles were synthesized using lithium ions to increase the aqueous electrical conductivity of the solution and precisely control the size, shape, and size distribution of the particles. In this study, the conventional approach of increasing particle size by the concentration of copper ions and PGPPE in a copper chloride solution was compared to increasing the concentration of lithium chloride when the copper chloride concentration was held constant. Particle size and shape were characterized by TEM, and the size distribution of the particles at different concentrations was obtained by particle size analysis. Increasing the concentration of copper ion in the solution greatly increased the aqueous electric conductivity and the size of the particles but led to a wide size distribution ranging from 150 nm to 400 nm and rough particle morphology. The addition of lithium ions increased the size of the particles, but maintains them in a range of 250 nm. In addition the particles exhibited spherical shape as determined by TEM. The addition of lithium ions to the solution has the potential to synthesize nanoparticles with optimal characteristics for printing applications by maintaining a narrow size range and spherical shape.


1953 ◽  
Vol 31 (7) ◽  
pp. 638-652 ◽  
Author(s):  
M. W. Lister

New methods are given for the preparation of sodium copper (111) tellurate, Na9Cu(TeO6)2.16H2O, and sodium copper (111) periodate, Na7Cu(IO6)2.20H2O, previously reported by Malatesta. Additional analytical evidence is presented that these are really compounds of trivalent copper. The dissociation of the ions in alkaline aqueous solution was examined through the ability of the uncomplexed copper to catalyze the decomposition of sodium hypochlorite. Evidence is presented that the uncomplexed copper ion is Cu(OH)4−, and this gives both a 1-1 and a 1-2 complex with both tellurate and periodate. The 1-2 complexes appear to be Cu(HTeO6)2−7 and Cu(IO6)2−7 respectively; the 1-1 complexes are less stable. The equilibrium constants for the reversible dissociation of these ions into their simpler constituents in aqueous solution at 40 °C. are as follows: tellurate, 1-1 complex K1 = 1.8 × 10−6; 1-2 complex K2 = 1.1 × 10−11; periodate, 1-1 complex K1 = 3.4 × 10−5; 1-2 complex is K2 = 8.0 × 10−11. The smaller the constant the more stable the complex ion. In the case of the tellurate complex K2 is proportional to the square of the hydroxide ion concentration and these values are for 0.400 M sodium hydroxide; with periodate K2 is independent of the hydroxide concentration. Experiments at various temperatures give 20 kcal. as the heat of the reaction forming the 1-2 tellurate complex from the simple ions, and 71/2 kcal. for the 1-2 periodate complex. The stannate, stibnate, and selenate ions showed no signs of forming analogous compounds.


2020 ◽  
Vol 54 (19) ◽  
pp. 2599-2609
Author(s):  
Abtin Heydarian ◽  
Seyed Abdolkarim Sajjadi ◽  
Mats Johnsson

In this study, the effect of SiC particle size on the sintering behavior of SiC-Si nano composites fabricated by spark plasma sintering (SPS) technique was investigated and a model was proposed, accordingly. To this purpose, SiC powders with three different particle sizes of 25 µm, 80 nm and 45 nm were chosen. It was expected that hardness of the composites increase with decreasing the SiC particle size; however, the outcomes were interesting and unpredictable. The composite with 80 nm SiC particles indicated the highest hardness. Hardness of the specimen with 25 µm SiC was low because of the large particle size of its reinforcement. While 80 and 45 nm SiC particles are considered as nano particles, the composite with 45 nm SiC particles showed lower hardness due to the growth of SiC powders during sintering according to a proposed model. Two reasons for the growth of 45 nm SiC particles were defined: (i) the fineness of the SiC particles prevented the Si particles to act as a binder between them thus, they agglomerated; (ii) SiC powders were oxidized during mixing procedure and a layer of SiO2 was formed on their surfaces. During sintering procedure, the reaction between SiC and SiO2 was happened and as a result SiO was formed. It caused vapor transportation during sintering leading to necking between particles and in turn, grain growth.


2011 ◽  
Vol 8 (s1) ◽  
pp. S377-S391 ◽  
Author(s):  
U. Gayathri ◽  
B. R. Venkatraman ◽  
S. Arivoli

The main purpose of this work was to exploit low cost and efficient sorbents for the removal of copper from aqueous solution usingCynodon dactyloncarbon. It was observed from the experimental results that almost 90-100% copper can be removed from the aqueous solution. Adsorption kinetics and equilibrium have been investigated as a function of initial copper ion concentration. pH, contact time and adsorbent dosage. Kinetics studies suggested that the adsorption allowed first order reaction. Equilibrium data were analyzed using Langmuir and Freundlich isotherm models. On the basis of experimental results and the model parameters, it can be concluded that the carbonaceousCynodon dactylonis effective for the removal of copper ion from aqueous solution.


2008 ◽  
Vol 368-372 ◽  
pp. 348-351
Author(s):  
Lin Wang ◽  
Jia Xiang Zhong ◽  
Bin Ma ◽  
Shu Jun Wang

In this paper, the application of new functional nano-material films prayed on transmission display screen is studied. Optical properties, such as luminance gain and scattering angle, of the screens are measured to investigate the particle size effects on the properties. The results show that the optical properties of screen sprayed with nano-material film improve notably compared with those screens with films of conventional particle sizes. When the particle size is less than 100nm, the gain is high and the viewing angle low. With increasing particle sizes, the characteristics of screens vary with particle sizes. In order to solve the contradictory relationship between gain and viewing angle and to obtain screens with desirable optical properties, suitable nano-particle sizes ranging from 400nm to 700nm should be chosen for the spraying film. The scattering mechanisms between nano-particles and light are also discussed.


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