Electrical and optical properties of well-dispersed MWCNTs/PVA nanocomposites under different pH conditions

2018 ◽  
Vol 32 (4) ◽  
pp. 442-453 ◽  
Author(s):  
Emad AM Farrag ◽  
Rami A Abdel-Rahem ◽  
SS Ibrahim ◽  
Ayman S Ayesh
Keyword(s):  
Room Temperature ◽  
Ph Value ◽  
Poly Vinyl Alcohol ◽  
Electrical And Optical Properties ◽  
Multiwalled Carbon ◽  
Casting Technique ◽  
Ph Values ◽  
Current Voltage ◽  
Optimum Ph ◽  
Ph Conditions

Series of polymer nanocomposites films consisting of pretreated multiwalled carbon nanotubes (PT-MWCNTs) and poly (vinyl alcohol) (PVA) were prepared at room temperature. The MWCNTs were initially pretreated with 1.0 M sulfuric acid (PT-MWCNTs) and then allowed to disperse in aqueous solutions at different pH values (2–14). It was found that the dispersion of the PT-MWCNTs is a pH dependent. The best PT-MWCNTs dispersion was obtained at pH = 10. Films of PT-MWCNTs/PVA, at this optimum pH-value, were then prepared by casting technique at different PT-MWCNTs weight fractions. The resulted PT-MWCNTs/PVA films were characterized through the direct visualization, Fourier transform infrared, and morphology test. Besides, current–voltage and direct current electrical conductivity for PT-MWCNTs/PVA nanocomposites at 60°C showed that the conductivity mechanism was ohmic and the percolation threshold was around 0.8 wt% PT-MWCNTs. Optical results showed that PT-MWCNTs are homogeneously distributed in the neat PVA and optical gap is significantly decreased from 4.40 to 2.96 eV.

scholarly journals Producing Drink like Grafted Milk from Chickpeas and Evaluation of its Qualitative Properties

2020 ◽  
Vol 10 (03) ◽  
pp. 374-377
Author(s):  
Ibtihal Ismail Muhammad Al-Ani
Keyword(s):  
Room Temperature ◽  
Extraction Efficiency ◽  
Ph Value ◽  
Bacterial Number ◽  
Qualitative Properties ◽  
Product Density ◽  
Ph Values ◽  
Extraction Volume ◽  
Refrigerator Temperature ◽  
Soda Solution

The present study aimed to study the possibility of producing a drink that looks like grafted milk by using chickpeas and evaluate its physical, chemical, microbial, and sensory properties. The result showed the superiority of F treatment (soaking 100 grams of chickpeas at the refrigerator temperature 4ºC for 12 hours) over the rest seven treatments in extraction efficiency, which was 70%, while, it was 50.5% in H treatment (soaking 100 grams of chickpeas in the heated water at 60ºC for 30 minutes). The highest value of the product density was after water and flavorings addition in the D treatment (soaking 100 grams chickpeas in 0.05 soda solution at 60ºC for 30 minutes), and it was 0.97 g cm-3, compared with the lowest density 0.57 g cm-3 in A treatment (soaking 100 grams chickpeas in 0.05 soda solution at room temperature 25ºC for 12 hours). pH values were highest in A treatment compared with the other treatments, and its value was 7.66 in the 1st and 2nd day, after dissolving in a refrigerator at 4ºC, and then, for 5 minutes at room temperature 30ºC. The lowest value in the D treatment was 6.45 on the 1st day, and 6.87 on the 2nd day in the G treatment. On the 3rd day, the highest pH value was 7.13 in the D treatment, and the lowest value 6.79 was in the E treatment. pH highest value was 6.2 on the 4th day in A treatment. From the last results, it may be concluded that F treatment was the best in extraction efficiency, the final product density, and less total bacterial number, after dissolving for 5 days at refrigerator temperature 4ºC, and then, at room temperature 30ºC for 3 and 48 hours incubation. The best extraction volume and pH were in A treatment.

Electrical and Optical Properties of Silicone Oil/Carbon Nanotube Nanocomposites

2021 ◽  
Vol 21 (4) ◽  
pp. 2185-2195
Author(s):  
Jeferson Matos Hrenechen ◽  
Celso de Araujo Duarte ◽  
Ney Pereira Mattoso Filho ◽  
Evaldo Ribeiro
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Conduction Mechanism ◽  
Silicone Oil ◽  
Optical Transmittance ◽  
Liquid Matrix ◽  
Electrical And Optical Properties ◽  
Multiwalled Carbon ◽  
Liquid Matrices ◽  
The Matrix

The present work describes the preparation and the investigation of the room temperature electrical and optical properties of a series of liquid nanocomposites (lnC) prepared with different concentrations of multiwalled carbon nanotubes (MWCNT) in a variety of liquid matrices: glycerin, Vaseline, glucose, propylene glycol and silicone oil (SIO). Special attention is deserved to the SIO matrix, owing to its convenient electrical properties for our purposes. We verified that a small percent fraction of MWCNT dispersed along the SIO matrix is capable of improving the electrical conductivity of the matrix by orders of magnitude, indicating that the MWCNT strongly participates in the electrical conduction mechanism. Also, the application of an external electric field to this lnC resulted in large changes in the optical transmittance, that were interpreted as a consequence of the fieldinduced MWCNT alignment into the liquid matrix. The characteristics of such a new category of nanocomposite in the liquid state suggest further studies.

Coagulation-Direct Filtration of Soft, Low Alkalinity Humic Waters

1999 ◽  
Vol 40 (9) ◽  
pp. 55-62 ◽  
Author(s):  
Bjørnar Eikebrokk
Keyword(s):  
Natural Organic Matter ◽  
Pilot Scale ◽  
Quality Parameters ◽  
Efficient Removal ◽  
Direct Filtration ◽  
Ph Values ◽  
Optimum Ph ◽  
Calcium Sources ◽  
Ph Conditions ◽  
Removal Efficiencies

Optimisation of coagulation-direct filtration processes with respect to efficient removal of humic substances, i.e. natural organic matter (NOM) has gained a lot of focus in many countries over the last years. This paper presents experimental results from pilot scale research studies aimed at optimising the coagulation-direct filtration process applied to soft and humic raw waters with low turbidity and alkalinity levels. Comprehensive tests of 3 types of raw waters with different NOM content, 5 types of coagulants, and 3 calcium sources for the purpose of corrosion control have been conducted. Removal efficiencies with respect to relevant water quality parameters are presented, with typical relationships between raw water NOM content, coagulant dose requirements and pH. Generally, when applying metal-based coagulants, residual metal concentration was the critical parameter regarding minimum coagulant dose requirements. Typical NOM removal efficiencies were in the range of 75-90% and 40-70% with respect to colour and organic carbon, respectively. Optimum pH conditions for the removal of NOM and/or residual metals do not always coincide with that of turbidity. The experiments also showed that poly-aluminium and ferric chlorides might have some benefits over alum in terms of dose requirements and range of optimum pH values, and that chitosan may be used for colour removal with good results.

Effect of pH Value on Structural and Optical Properties of Transparent Nano-Crystalline TiO2 Films Prepared by Sol-Gel Dip-Drive Coating

2013 ◽  
Vol 678 ◽  
pp. 80-85 ◽  
Author(s):  
Krishnasamy Sakthivel ◽  
T. Venkatachalam
Keyword(s):  
Ab Initio ◽  
Room Temperature ◽  
Ph Value ◽  
Sol Gel ◽  
Structural And Optical Properties ◽  
Glass Substrates ◽  
Ph Values ◽  
Nano Crystalline ◽  
Crystalline Nature ◽  
Deposited Films

Thin films of TiO2 have been deposited on well cleaned glass substrates by Sol-Gel dip-drive coating technique. The films have been prepared at three different pH values (1, 3.5 & 9) of Sol and annealed in muffle furnace at 550°C for one hour and are allowed to cool to room temperature. The films were characterized by XRD, EDAX, SEM and UV-Vis Spectrophotometer. The as deposited films were found to be amorphous in nature. The annealed films exhibit anatase in crystalline structure. The EDAX results have shown that all the films are maintained with TiO2 in composition. The XRD results reveal that they are nano-crystalline in nature and the crystalline nature increases with pH of the Sol. The transmittance and absorbance spectra have shown that the films are transparent and band gap of the films are of the order of 3.2eV. The ab initio studies of TiO2 (using GGA) was performed with Vienna ab initio Simulation package and the band structure and effective masses of the electrons and holes were determined.

Pemanfaatan Hasil Samping Fermentasi Belimbing Wuluh (Asam Sunti) dalam Pengolahan Ikan

2018 ◽  
Vol 3 (2) ◽  
pp. 351-356
Author(s):  
Weny Weny ◽  
Rasdiansyah Rasdiansyah ◽  
Novia Mehra Erfiza
Keyword(s):  
Soluble Protein ◽  
Room Temperature ◽  
Storage Time ◽  
Ph Value ◽  
Block Design ◽  
Total Acid ◽  
Soaking Time ◽  
Ph Values ◽  
Randomized Block Design ◽  
And Storage

Abstrak. Sampai saat ini belum ada penelitian lebih lanjut mengenai pemanfaatan hasil samping dari produk asam sunti. Tujuan penelitian ini untuk melihat pengaruh perendaman ikan di dalam air asam sunti dan penyimpanannya pada suhu ruang terhadap karakteristik ikan. Penelitian ini menggunakan Rancangan Acak Kelompok Faktorial dengan 2 faktor yaitu faktor waktu perendaman (W), yang terdiri dari 3 taraf (W1 : 30 detik, W2 : 5 menit, W3 : 10 menit) dan lama penyimpanan (S), yang terdiri dari 2 taraf (S1 : 0 jam, S2 : 2 jam). Hasil penelitian menunjukkan bahwa karakteristik air asam sunti pada uji pH memiliki rataan yaitu 1,27, total asam 49% dan total bakteri asam laktat  5,1×104 CFU/gram. Nilai pH ikan setelah direndam air asam sunti 5,22-5,65 dengan rataan 5,43 dan nilai protein terlarut berkisar antara 18,42-18,74% dengan rataan 18,74%.Dari penelitian didapatkan bahwa waktu perendaman (W) berpengaruh nyata (P≤0,05) terhadap nilai protein terlarut dari ikan namun berpengaruh tidak nyata (P0,05) terhadap nilai pH ikan, uji deskriptif aroma dan tekstur ikan. Lama penyimpanan (S) berpengaruh sangat nyata (P≤0,01) terhadap nilai pH ikan setelah perendaman namun berpengaruh tidak nyata (P0,05) terhadap uji deskriptif aroma dan tekstur ikan. Interaksi waktu perendaman dengan lama penyimpanan berpengaruh nyata (P≤0,05) terhadap nilai pH ikan namun berpengaruh tidak nyata terhadap uji deskriptif aroma dan tekstur ikan.Waktu perendaman ikan di dalam air asam sunti selama 10 menit dapat menghambat kenaikan pH ikan selama penyimpanan sampai 2 jam. Semakin lama perendaman ikan di dalam air asam sunti maka semakin tinggi protein terlarut dari ikan.  Abstrack. Therefore, this study was conducted to see the effect of soaking the fish in asam sunti water and its storage at room temperature on the characteristics of the fish. This study uses a randomized block design factorial with 2 factors: soaking time (W), consisting of 3 levels (W1: 30 seconds, W2: 5 minutes, W3: 10 minutes) and storage time (S), consisting of 2 levels ( S1: 0 hours, S2: 2 hours). The results showed pHof asam sunti water is 1.27,  total acid is 49% and lactic acid bacteria has  of  5.1 × 104 CFU / gram and the soaked fish has pH values ranged from 5.22 to 5.65 with the average of 5.43 and soluble protein values ranged from 18.42 to 18.74% with the average 18.74%.The results indicated that the soaking time (W) has effect significantly to the value of soluble protein (P≤0,05) of fish but iteffect not significantly (P 0.05) on pH value of fish, descriptive test the of aroma and texture of the fish. Storage time (S) effect significantly (P≤0,01) to pH value of fish after soaking but it effectnot significantly (P 0.05) to the descriptive test of  aroma and texture of the fish. Interaction withsoaking time and storage (WxS) effect significantly (P≤0,05) to pH value of fish but it effect to not significantly the descriptive test of aroma and texture of the fish.Soaking time the fish in water for 10 minutes sunti can inhibit increasing in the pH of the fish during storage up to 2 hours. The longer soaking time of the fish in the asam sunti water, the higher sunti acid soluble proteins from value.

Influence of Pulp pH on Flotation of Fluorite and Calcite

2012 ◽  
Vol 616-618 ◽  
pp. 614-618
Author(s):  
Wen Juan Zhao ◽  
Dian Wen Liu ◽  
Hong Shuai Li ◽  
Qi Cheng Feng ◽  
Guo Yin Xu ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Fatty Acid ◽  
Significant Role ◽  
Ph Value ◽  
Froth Flotation ◽  
Point Of Zero Charge ◽  
Zeta Potentials ◽  
Ph Values ◽  
Zero Charge ◽  
Optimum Ph

Pulp pH value plays a significant role in the froth flotation. Especially in the flotation of fluorite, the performance of flotation will be affected greatly by pulp pH. MO, a new kind of modified fatty acid was used as collector, and H2SO4 and Na2CO3 were used to regulate pulp pH in the experiment. The mechanism of influence of pulp pH on flotation of fluorite and calcite was investigated by such parameters as fluorite recovery, zeta potentials and the infrared spectroscopy about minerals at different pulp pH values. As is shown in the results, the point of zero charge(PZC) of fluorite is pH=9.5 and the PZC of calcite is pH=8.5. The optimum pulp pH of the flotation of fluorite and calcite is determined as 9.5~10 and 8~9 respectively. pH value should be controlled above 9 to depress calcite. Finally, 9.5~10 was determined as the optimum pH to float the fluorite from the calcium-containing fluorite ores.

ELECTRICAL AND OPTICAL PROPERTIES OF OLED USING NEW EMISSIVE MATERIAL Al2Nq4

2006 ◽  
Vol 05 (06) ◽  
pp. 859-864
Author(s):  
KI-SUNG YANG ◽  
HO-SIK LEE ◽  
SEUNG-UN KIM ◽  
YOON-KI JANG ◽  
DOO-SEOK KIM ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
System Model ◽  
Flat Panel Display ◽  
Flat Panel ◽  
Electrical And Optical Properties ◽  
Light Emitting ◽  
Current Voltage ◽  
Analysis System ◽  
Green Photoluminescence

Since the first report of the light-emitting diodes based on Alq 3, many organic materials have been synthesized and extended efforts have been made to obtain high performance electroluminescent (EL) device. We synthesized new emissive material, 1, 4-dihydoxy-5, 8-naphtaquinone· Alq 3 complex( Al 2 Nq 4), and extended efforts have been made to obtain high-performance electroluminescent (EL) devices. Current–voltage (I–V) and luminance–voltage (L–V) characteristics were measured by Flat Panel Display Analysis System (Model 200-AT) at room temperature. The Al 2 Nq 4 shows green photoluminescence and electroluminescence spectra at about 510 nm, and ITO/Al 2 Nq 4/Cathode device shows typical rectifying characteristics.

scholarly journals The Proliferation Rule of Microcystis Aeruginosa Under Different Initial pH Conditions and its Influence on the pH Value of the Environment

2021 ◽  
Author(s):  
Sijie Wei ◽  
Guanjie Zhuang ◽  
Lirijian Cheng ◽  
Shoubing Wang
Keyword(s):  
Microcystis Aeruginosa ◽  
Ph Value ◽  
Control Strategies ◽  
Scientific Basis ◽  
Cyanobacterial Blooms ◽  
Ph Values ◽  
Inoculation Density ◽  
Initial Ph ◽  
Ph Conditions ◽  
Optimal Ph

Abstract This study investigated the characteristics of the proliferation process of Microcystis aeruginosa and its changes to environmental pH values under different initial pH values and different initial inoculation densities. The results showed that although the initial pH value or the initial inoculation density was different, the pH values of the culture systems fluctuated up and down throughout the proliferation of M. aeruginosa, both on a daily and hourly time scale, and then tended to stabilize around the same value of 10.0 at the end of proliferation. The optimal pH value for the proliferation of M. aeruginosa was 9.56. This study creatively proposes that the period when the environmental pH value starts to rise rapidly toward 9.0 could be selected as an early warning period for a cyanobacterial outbreak, and the environmental pH value could be adjusted to below 8.0 to delay the outbreak. These results provide a scientific basis for further understanding the mechanism of cyanobacterial blooms and formulating pH-based control strategies.

Experimental Study of Coagulation Treatment of the Arsenic-Containing Rural Drinking Groundwater

2012 ◽  
Vol 610-613 ◽  
pp. 2197-2202
Author(s):  
Jing Liu ◽  
Hua Yang ◽  
Yan Zuo ◽  
Zhi Min Ren ◽  
De Jun Bian
Keyword(s):  
Experimental Study ◽  
Drinking Water ◽  
Room Temperature ◽  
Arsenic Removal ◽  
Ph Value ◽  
Experimental Results ◽  
Ph Values ◽  
Neutral Ph ◽  
Removal Of Arsenic ◽  
Sedimentation Time

The arsenic-containing rural drinking groundwater was treated by coagulation method in the paper. It was studied that the varieties and dosages of coagulants, pH value and sedimentation time have an effect on removal of arsenic. The experimental results indicated that the rate of arsenic removal is able to reach 95.6% at room temperature and under the condition of neutral pH values, 20 mg of Fe2(SO4)3 as coagulant and 1 h of sedimentation time. The content of arsenic in the treated drinking groundwater can be up to the current national hygiene standards of rural drinking water (<0.05mg /L).

scholarly journals Gas Sensing with Solar Cells: The Case of NH3 Detection through Nanocarbon/Silicon Hybrid Heterojunctions

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2303
Author(s):  
Giovanni Drera ◽  
Sonia Freddi ◽  
Tiziano Freddi ◽  
Andrea De Poli ◽  
Stefania Pagliara ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Gas Sensors ◽  
Room Temperature ◽  
Open Circuit Voltage ◽  
Gas Sensing ◽  
Open Circuit ◽  
Multiwalled Carbon ◽  
Single Walled Carbon Nanotube ◽  
Cell Parameters ◽  
Current Voltage

Photovoltaic (PV) cells based on single-walled carbon nanotube (SWCNT)/silicon (Si) and multiwalled carbon nanotube (MWCNT)/Si junctions were tested under exposure to NH3 in the 0–21 ppm concentration range. The PV cell parameters remarkably changed upon NH3 exposure, suggesting that these junctions, while being operated as PV cells, can react to changes in the environment, thereby acting as NH3 gas sensors. Indeed, by choosing the open-circuit voltage, VOC, parameter as read-out, it was found that these cells behaved as gas sensors, operating at room temperature with a response higher than chemiresistors developed on the same layers. The sensitivity was further increased when the whole current–voltage (I–V) curve was collected and the maximum power values were tracked upon NH3 exposure.

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