THE EFFECT OF DIFFERENT PARAMETERS ON THE FUNCTIONALIZATION OF MWCNTs VIA ACID TREATMENT

2010 ◽  
Vol 09 (03) ◽  
pp. 175-180 ◽  
Author(s):  
F. MAJEDI ◽  
S. ZAVAREH ◽  
M. SH. SHARIF ◽  
F. GOLESTANI-FARD
Keyword(s):  
Nitric Acid ◽  
Ftir Spectroscopy ◽  
Functional Groups ◽  
Raman Spectra ◽  
Acid Concentration ◽  
Acid Treatment ◽  
Soaking Time

In this report, the functionalization of MWCNTs in sulfuric/nitric acid is studied, and the influences of acid concentration, temperature and time on functionalization are assessed. Fourier Transmission Infrared (FTIR) spectroscopy was employed to study the functional groups of different samples. The optimal results for complete functionalization were achieved by the addition of 5 mg/ml of MWCNTs to acid, at a temperature of 100°C with 3 h of soaking time. The correlation between the FTIR and Raman spectra of the optimized sample was determined, and the effect of functional groups on the G and D bands is discussed.

A Study of Surface Modification on Adsorption Behaviors of Nanoporous Carbon

2007 ◽  
Vol 119 ◽  
pp. 211-214 ◽  
Author(s):  
Byeoung Ku Kim ◽  
Young Seak Lee ◽  
Seung Kon Ryu ◽  
Byung Joo Kim ◽  
Soo Jin Park
Keyword(s):  
Nitric Acid ◽  
Functional Groups ◽  
Carbon Fibers ◽  
Acid Treatment ◽  
Surface Acidity ◽  
Activated Carbon Fibers ◽  
Adsorption Behaviors ◽  
Toxic Gases ◽  
Adsorption Amount ◽  
Polar Functional Groups

In this work, to introduce polar functional groups on carbon surfaces, activated carbon fibers (ACFs) were treated by nitric acid in order to enhance the adsorption capacity of propylamine which was one of toxic gases in cigarette smoke. It was found that the polar functional groups were predominantly increased up to 2.0 M of nitric acid, resulting in the increase of total surface acidity. It was found that the adsorption amount of propylamine of the modified ACFs was increased around 17% after a nitric acid treatment. From the XPS results, it was observed that propylamine was reacted with strong or weak polar (acidic) groups, such as COOH, -COO or OH existed on the ACF surfaces.

Improvement in electrochemical capacitance of activated carbon from scrap tires by nitric acid treatment

2014 ◽  
Vol 8 (4) ◽  
pp. 391-398 ◽  
Author(s):  
Yan Han ◽  
Ping-Ping Zhao ◽  
Xiao-Ting Dong ◽  
Cui Zhang ◽  
Shuang-Xi Liu
Keyword(s):  
Activated Carbon ◽  
Nitric Acid ◽  
Acid Treatment ◽  
Electrochemical Capacitance ◽  
Scrap Tires

scholarly journals Qualitative Analysis of Traditional Italian Dishes: FTIR Approach

2018 ◽  
Vol 10 (11) ◽  
pp. 4112 ◽  
Author(s):  
Alessandra Durazzo ◽  
Johannes Kiefer ◽  
Massimo Lucarini ◽  
Emanuela Camilli ◽  
Stefania Marconi ◽  
...  
Keyword(s):  
Qualitative Analysis ◽  
Ftir Spectroscopy ◽  
Functional Groups ◽  
Food Systems ◽  
Principal Component ◽  
Integrated Approach ◽  
Spectroscopic Characterization ◽  
Cooking Methods ◽  
Food Research ◽  
The Individual

Italian cuisine and its traditional recipes experience an ever-increasing popularity around the world. The “Integrated Approach” is the key to modern food research and the innovative challenge for analyzing and modeling agro-food systems in their totality. The present study aims at applying and evaluating Fourier Transformed Infrared (FTIR) spectroscopy for the analysis of complex food matrices and food preparations. Nine traditional Italian recipes, including First courses, One-dish meals, Side courses, and Desserts, were selected and experimentally prepared. Prior to their analysis via FTIR spectroscopy, the samples were homogenized and lyophilized. The IR spectroscopic characterization and the assignment of the main bands was carried out. Numerous peaks, which correspond to functional groups and modes of vibration of the individual components, were highlighted. The spectra are affected by both the preparation procedures, the cooking methods, and the cooking time. The qualitative analysis of the major functional groups can serve as a basis for a discrimination of the products and the investigation of fraud. For this purpose, the FTIR spectra were evaluated using Principal Component Analysis (PCA). Our results show how the utilization of vibrational spectroscopy combined with a well-established chemometric data analysis method represents a potentially powerful tool in research linked to the food sector and beyond. This study is a first step towards the development of new indicators of food quality.

scholarly journals Pengaruh Konsentrasi Asam Askorbat dan Waktu Perendaman terhadap Kadar Air dan Bilangan Peroksida pada Minyak Kopra

2016 ◽  
Vol 8 (1) ◽  
pp. 29-32
Author(s):  
Erma Suryani ◽  
Virna Muhardina
Keyword(s):  
Ascorbic Acid ◽  
Moisture Content ◽  
Water Content ◽  
Acid Concentration ◽  
Fat Content ◽  
Peroxide Number ◽  
Ascorbic Acid Concentration ◽  
High Fat ◽  
Soaking Time ◽  
Randomized Design

(Effect of Ascorbic Acid Concentration and Soaking Time on Water Content And Peroxide Numbers of Copra Oil) ABSTRACT. Copra oil is a product produced from the dried coconut through several stages of drying until the moisture content reaches 5-6%. Copra oil susceptible to oxidation due to containing high fat content. This causes the oil susceptible to rancidity, discoloration and odor. One of the efforts to prevent the oxidation of foods high in fat can be done with the giving ascorbic acid as an antioxidant. The purpose of this study was to determine the ascorbic acid concentration and coconut meat soaking time in the solution as well as to determine the effect of ascorbic acid on the water content and peroxide numbers of copra oil. This study used a Complete Randomized Design (CRD) with 2 factorial and three levels: (1) ascorbic acid concentration (0.5%, 1% and 1.55%) and (2) soaking time (10 minutes, 20 minutes and 30 minutes). The results showed that ascorbic acid concentration has significant effect (P≤0,01) on peroxide number. While soaking time has significant effect on the water content and peroxide.

Raman and FTIR Spectroscopy of Synthetic Amphiboles: II. Divalent (Mg,Co) Substitutions at the Octahedrally Coordinated Sites

2021 ◽  
Author(s):  
Giancarlo Della Ventura ◽  
Boriana Mihailova ◽  
Frank C. Hawthorne
Keyword(s):  
Infrared Spectroscopy ◽  
Ftir Spectroscopy ◽  
Raman Spectra ◽  
Structure Refinement ◽  
Chemical Compositions ◽  
Mode Behavior ◽  
Wavenumber Region

Abstract Raman spectra were recorded for a set of synthetic amphiboles, Na(NaCa)(Mg5–xCox)Si8O22(OH)2 with x = 0–5, that have been previously characterized by Rietveld structure refinement and infrared spectroscopy in the principal OH-stretching region. The chemical compositions derived from the intensities of the O-H stretching Raman peaks are in accord with the nominal compositions, as well as with the compositions previously determined by both Rietveld structure refinement and infrared spectroscopy. Detailed peak assignments have been made of the Raman spectra in the low-wavenumber region (50–1200 cm–1) starting from the work of Leissner et al. (2015) and Waeselmann et al. (2019) and the simulated partial Raman spectra for all the cation-anion pairs in the structure of potassic-magnesio-arfvedsonite given by Ivanov et al. (2018). Most Raman peaks exhibit one-mode behavior and shift toward lower wavenumbers for increasing Co in the amphibole.

scholarly journals Effect of Surface Modification with Different Acids on the Functional Groups of AF 5 Catalyst and Its Catalytic Effect on the Atmospheric Leaching of Enargite

2019 ◽  
Vol 3 (2) ◽  
pp. 45 ◽  
Author(s):  
Jahromi ◽  
Ghahreman
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Elemental Sulfur ◽  
Catalytic Properties ◽  
Copper Recovery ◽  
Pre Treatment ◽  
Sulfur Adsorption

Carbon-based catalysts can assist the oxidative leaching of sulfide minerals. Recently, we presented that AF 5 Lewatit® is among the catalysts with superior enargite oxidation capacity and capability to collect elemental sulfur on its surface. Herein, the effect of acid pre-treatment of the AF 5 catalyst was studied on the AF 5 surface, to further enhance the catalytic properties of AF 5. The AF 5 catalyst was pretreated by hydrochloric acid, nitric acid and sulfuric acid. The results showed that the acid treatment drastically changes the surface properties of AF 5. For instance, the concentration of quinone-like functional groups, which are ascribed to the catalytic properties of AF 5, is 45.4% in the sulfuric acid pre-treatment AF 5 and only 29.8% in the hydrochloric acid-treated AF 5. Based on the C 1s X-ray photoelectron spectroscopy (XPS) results the oxygenated carbon is 30.6% in the sulfuric acid-treated AF 5, 29.2% in the nitric acid-treated AF 5 and 28.3% in the hydrochloric acid-treated AF 5. The nitric acid pre-treated AF 5 resulted in the highest copper recovery during the oxidative enargite leaching process, recovering 98.8% of the copper. The sulfuric acid-treated AF 5 recovered 97.1% of the enargite copper into the leach solution. Among different leaching media and pre-treatment the lowest copper recovery was achieved with the HCl pre-treated AF 5 which was 88.6%. The pre-treatment of AF 5 with acids also had modified its elemental sulfur adsorption capacity, where the sulfur adsorption on AF 5 was increased from 30.9% for the HCl treated AF 5 to 51.1% for the sulfuric acid-treated AF 5.

Recovery of Heavy Metals from the Spent Catalyst of the Hydrotreating Unit (HDT) for the Use of the Impregnation of Supported Catalysts

2018 ◽  
Vol 792 ◽  
pp. 133-139 ◽  
Author(s):  
Toapanta Germania ◽  
Caterine Donoso ◽  
María José Cárdenas ◽  
Amón Bolívar ◽  
Vladimir Ortiz
Keyword(s):  
Heavy Metals ◽  
Nitric Acid ◽  
Acid Concentration ◽  
Supported Catalysts ◽  
Nitric Acid Concentration ◽  
Added Value ◽  
High Tech ◽  
Spent Catalyst ◽  
X Ray ◽  
Spent Catalysts

Spent catalysts contain metals that have a high added value. From all metals, lanthanum has attracted a lot of attention due to the growing demand in the high-tech. The spent catalyst of the hydrotreatment unit is a material composed of lanthanum-enriched matrix of amorphous aluminosilicates. The experiment was carried out with a spent catalyst with a constant particle size of 90 μm. The treatments were obtained applying of two level factorial design to investigate the effect of following factors: temperature (20 - 60 °C), nitric acid concentration (3 - 6 M), leaching time (1 - 4 h) and percent solids (10 - 20 %). The research is carried out in two steps process: pretreatment of the catalyst and leaching with nitric acid. The leaching results show a yield of lanthanum of 99.44% using the following conditions: temperature (20 °C), nitric acid concentration (3M), leaching time (1 h), percent solids (20%) and 300 rpm. The principal analysis of the spent catalyst was carried out using the X-Ray Fluorescence (XRF) technique, 3.08%, while the percentage of lanthanum recovery in the extract, washing and refining was carried out using the Inductive Coupling Plasma (ICP) technique.

The effect of nitric acid (HNO3) treatment on the electrical conductivity and stability of poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) thin films

2017 ◽  
Vol 37 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Suhana Mohd Said ◽  
Shahriar Mufid Rahman ◽  
Bui Duc Long ◽  
Subramanian Balamurugan ◽  
Norhayati Soin ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Nitric Acid ◽  
Acid Treatment ◽  
Base Material ◽  
Operating Conditions ◽  
Organic Polymer ◽  
Visible Range ◽  
Infrared Analysis ◽  
Conductivity Enhancement ◽  
Improved Stability

Abstract In this work, the posttreatment of an organic polymer is performed using an inorganic acid, nitric acid (HNO3). We picked poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the base material and improved its electrical conductivity by acid treatment with different concentrations of HNO3. The acid treatment was able to achieve the optimum electrical conductivity of 197 S/cm, which is 115.5 times higher than the base material when treated with an aqueous solution containing 65% of HNO3. Moreover, the films showed higher transparency in the visible range while conducting Fourier transform infrared analysis. In addition, the treated films showed improved stability against outdoor operating conditions in terms of sheet resistance compared with untreated PEDOT:PSS films. We tried to develop a hypothesis to describe the reason behind the electrical conductivity enhancement by studying the thicknesses of all the samples at different acid concentration levels. The results from atomic force microscopy, the Hall effect, and the trend of film thickness suggest that the conformational change, the removal of excess PSS from the polymer, and the increase in carrier concentration are the reasons behind the improvement in electrical conductivity.

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