scholarly journals 3-Mercaptopropyltrimethoxysilane Modified Diatomite: Preparation and Application for Voltammetric Determination of Lead (II) and Cadmium (II)

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Dinh Quang Khieu ◽  
Bui Hai Dang Son ◽  
Vo Thi Thanh Chau ◽  
Pham Dinh Du ◽  
Nguyen Hai Phong ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Fourier Transformation ◽  
Treatment Temperature ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Paste Electrode ◽  
Modified Diatomite

In this study, functionalized diatomite was prepared by grafting of 3-mercaptopropyltrimethoxysilane (MPTMS) to diatomite (MPTMS-diatomite). The diatomite with thermal treatment from 100 to 700°C was functionalized by MPTMS under dry and humid conditions. The obtained MPTMS-diatomite was characterized by X-ray diffraction (XRD), thermal gravity-differential scanning calorimeter (TG-DSC), and Fourier transformation infrared (FT-IR). The results showed that an increase in treatment temperature seems to reduce the loading of MPTMS onto diatomite. The humidity of diatomite was favorable for the grafting of functional groups on the surface. The possible mechanisms of MPTMS loading to diatomite (MPTMS-diatomite) were also proposed. The performance of a carbon paste electrode (CPE) modified with MPTMS-diatomite in the simultaneous determination of Cd(II) and Pb(II) ions was addressed.

scholarly journals Fabrication of a Food Nano-Platform Sensor for Determination of Vanillin in Food Samples

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2817 ◽  
Author(s):  
Vinod Gupta ◽  
Hassan Karimi-Maleh ◽  
Shilpi Agarwal ◽  
Fatemeh Karimi ◽  
Majede Bijad ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Food Samples ◽  
Precipitation Method ◽  
Single Wall Carbon Nanotubes ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Paste Electrode

Herein, we describe the fabrication of NiO decorated single wall carbon nanotubes (NiO-SWCNTs) nanocomposites using the precipitation method. The synthesized NiO-SWCNTs nanocomposites were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Remarkably, NiO-SWCNTs and 1-butylpyridinium hexafluorophosphate modified carbon paste electrode (CPE/NiO-SWCNTs/BPrPF6) were employed for the electrochemical detection of vanillin. The vanillin sensor showed an ultra-high sensitivity of 0.3594 μA/μM and a low detection limit of 0.007 μM. In the final step, the NiO-SWCNTs/BPrPF6 was used as the suitable tool for food analysis.

Sensitive Electrochemical Determination of Hyperin Based on Electrochemically Activated ZrO2 Nanoparticles-Modified Carbon Paste Electrode

NANO ◽  
2019 ◽  
Vol 14 (05) ◽  
pp. 1950052 ◽  
Author(s):  
Na Wang ◽  
Jianyao Kou ◽  
Lijie Wang ◽  
Fei Wang ◽  
Kui Lu
Keyword(s):  
Carbon Paste Electrode ◽  
Electrochemical Treatment ◽  
Electrochemical Determination ◽  
Zro2 Nanoparticles ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
Sensitive Determination ◽  
Paste Electrode

A novel electrochemically activated ZrO2 nanoparticles modified carbon paste electrode (CPE) (ZrO2-CPE(ox)) was prepared and applied for selective and sensitive determination of hyperin. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectra and electrochemical experiment were used to characterize the ZrO2 nanoparticles and investigate the electrochemical performance of the ZrO2-CPE(ox). Compared with bare CPE and electrochemically activated CPE (CPE(ox)), the ZrO2-CPE(ox) got more reactive sites by electrochemical treatment and exhibited larger effective surface area and more excellent electrochemical catalytic activity toward the redox of hyperin. Under the optimum conditions, the oxidation peak currents showed a linear relationship with the concentrations of hyperin in the range of [Formula: see text]–[Formula: see text][Formula: see text]mol[Formula: see text]L[Formula: see text] and [Formula: see text]–[Formula: see text][Formula: see text]mol[Formula: see text]L[Formula: see text], and a low detection limit of [Formula: see text][Formula: see text]mol[Formula: see text]L[Formula: see text] was achieved for hyperin. Moreover, the proposed method exhibited an excellent selectivity, stability, reproducibility and repeatability, which make it very suitable for a potential choice for determining the concentrations of hyperin in drug matrices.

Indirect Differential Pulse Voltammetric Determination of Fluoride Ions at Carbon Paste Electrode Modified with Porous and Electroactive Fe3+/Fe2+ Based-Metal Organic Frameworks Type MIL-101(Fe)

2021 ◽  
Author(s):  
Ashraf Mahmoud ◽  
Mater Mahnashi ◽  
Samer Abu-Alrub ◽  
Saad Kahatani ◽  
Mohamed El-Wekil
Keyword(s):  
Carbon Paste Electrode ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Metal Organic Frameworks ◽  
Differential Pulse ◽  
Carbon Paste ◽  
X Ray ◽  
Metal Organic ◽  
Paste Electrode

Abstract An innovative and reliable electrochemical sensor was proposed for simple, sensitive and selective determination of F- ions. The sensor is based on the fabrication of porous and electroactive Fe-based metal organic frameworks [MIL-101(Fe)]. It was blended with graphite powder and liquid paraffin oil to from carbon paste electrode (CPE). The MIL-101(Fe)@CPE was characterized using different techniques such as scanning electron microscope, powder X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, energy dispersive X-ray, cyclic voltammetry, electrochemical impedance spectroscopy, differential pulse voltammetry. The MIL-101(Fe)@CPE exhibited two redox peaks (anodic and cathodic) corresponding to Fe3+ and Fe2+, respectively. The determination of F- ions based on the formation of a stable fluoroferric complex with Fe3+/ Fe2+, decreasing the currents of redox species. It was found that the anodic peak current (Ipa) is linearly proportional to the concentration of F- in the range of 0.67-130 µM with a limit of detection (S/N=3) of 0.201 µM. The electrode exhibited good selectivity towards F- detection with no significant interferences from common anions. The as-fabricated sensor was applied for the determination of F- in environmental water samples with recoveries % and RSDs % in the range of 98.1-102.4 % and 2.4-3.7 %, respectively.

A novel two-dimensional layered Cu2+ complex based on Dawson-like [H3BiW18O60]6−: synthesis, structure and magnetic properties

2018 ◽  
Vol 74 (11) ◽  
pp. 1267-1273
Author(s):  
Shuai He ◽  
Ying Xin ◽  
Jiansheng Li ◽  
Zaiming Zhu ◽  
Peng Zhao ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Electrochemical Behaviour ◽  
Exchange Interactions ◽  
Antiferromagnetic Exchange ◽  
Two Dimensional ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dimensional Network ◽  
Paste Electrode

A novel complex based on the Dawson-like [H3BiW18O60]6−, i.e. (C2H9N2)2[{Cu(C10H8N2)(C2H8N2)}2(H3BiW18O60)]·5.5H2O or (enH)2[{Cu(2,2′-bipy)(en)}2(μ4-H3BiW18O60)]·5.5H2O, (1), where enH is protonated ethane-1,2-diamine, 2,2′-bipy is 2,2′-bipyridine and en is ethane-1,2-diamine, has been synthesized hydrothermally and characterized by elemental analysis, single-crystal X-ray diffraction analysis, IR spectroscopy, powder XRD, and thermogravimetry and differential thermal analysis (TG–DTA). For (1), each [H3BiW18O60]6− anion acts as a tetradentate ligand connecting [Cu(2,2′-bipy)(en)]2+ fragments via two terminal and two bridging O atoms, forming a two-dimensional network structure. Along the a and c axes, polyoxometalate units are arranged in an AB…AB manner. The electrochemical behaviour of (1)–CPE (CPE is a carbon paste electrode) was investigated in 2 M H2SO4 solution by cyclic voltammetry (CV). The redox process of WVI/V takes place at E 1/2 = −0.58 (I–I′) and −0.37 V (II–II′), and at −0.04 V (III–III′) for CuII/0. The magnetic properties of (1) were investigated in the range 2–300 K and indicated the existence of strong antiferromagnetic exchange interactions between the Cu2+ centres.

Comparison of FT-IR, Thermal Analysis and XRD for Determination of Products of Cement Hydration

2010 ◽  
Vol 168-170 ◽  
pp. 518-522 ◽  
Author(s):  
Zhi Hua Ou ◽  
Bao Guo Ma ◽  
Shou Wei Jian
Keyword(s):  
Thermal Analysis ◽  
Fourier Transform ◽  
Cement Hydration ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Cement Pastes ◽  
X Ray ◽  
Degree Of Hydration ◽  
Ft Ir

Fourier Transform Infrared Spectroscopy (FT-IR), thermal analysis and X-Ray Diffraction (XRD) are commonly performed to study the hydration products in cement pastes. The three methods were compared in this frame to detect products of cement hydration at different ages, especially at early ages (before 24h ages). The results indicate from the present experiment that CH (Calcium hydroxide) can be detected by three methods at all ages; C-S-H can be distinguished by FT-IR at all ages; ettringite may be detected by FT-IR before 24h ages and by XRD at all ages; and monosulphate can be detected by FT-IR before 24h ages. The process of cement hydration, characterized by formation and development of some hydration products, can be clearly observed by three methods. FT-IR is suggested for detecting the major hydration products before 24h ages, FT-IR and XRD are suggested for detecting the major hydration products after 24h ages, and thermal analysis is suggested for analyzing the degree of hydration quantitatively.

scholarly journals Effects of Thermal Treatment on Natural Clinoptilolite-Rich Zeolite Behavior in Simulated Biological Fluids

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2570
Author(s):  
Oana Cadar ◽  
Marin Senila ◽  
Maria-Alexandra Hoaghia ◽  
Daniela Scurtu ◽  
Ion Miu ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Crystalline Structure ◽  
Structural Changes ◽  
Biological Fluids ◽  
Treatment Temperature ◽  
Simulated Gastric Fluid ◽  
Gravimetric Analysis ◽  
X Ray ◽  
Ft Ir ◽  
Thermally Treated

This study presents the effect of thermal treatment (450, 500, 600, 750, and 800 °C) on a Romanian clinoptilolite-rich natural zeolite, along with the interaction of raw and thermally treated zeolites with simulated gastric fluid (SGF, pH = 1.20) at different zeolite to SGF ratios and exposure times. The zeolites were characterized using gravimetric analysis, X-ray fluorescence, powder X-ray diffraction (pXRD), and Fourier transform infrared (FT-IR) spectroscopy. The chemical composition of the zeolite subjected to thermal treatment did not change significantly with the increase of temperature. Structural changes were not detectable by pXRD and FT-IR analyses in the zeolites thermally treated up to 500 °C, while above 600 °C a gradual structural breakdown of zeolite was noticed. At high temperatures, the broad, low-intensity peaks in pXRD patterns indicated the partial amorphization of the crystalline structure. The pXRD and FT-IR analyses showed that the crystalline structure of zeolites remains unaffected after their exposure to SGF. The results revealed that the amounts of Fe, Na, Mg, K, Ca, Al, and Si released depends mainly on the zeolite to SGF ratio, and to a lower extent on the thermal treatment temperature, while the exposure time of 1 to 7 days does not have a significant impact on the elements released in SGF.

Adsorption of H2S Gas by Modified Diatomite and Leonardite

2019 ◽  
Vol 886 ◽  
pp. 130-137 ◽  
Author(s):  
Weerasak Chomkitichai ◽  
Panjaporn Sujit ◽  
Jiraporn Ketwaraporn ◽  
Pusit Pookmanee ◽  
Sukon Phanichphant ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Sodium Sulfide ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Modification Process ◽  
Gas Detector ◽  
Ft Ir ◽  
Lampang Province ◽  
Modified Diatomite

This research aimed to modify of diatomite and leonardite for adsorption of hydrogen sulfide (H2S) gas. The effect of chemical loading on surface modification was studied. Natural diatomite and leonardite were obtained through the natural deposits in Lampang Province, Thailand. Diatomite and leonardite were modified using chemical methods with calcination at 450 °C. The chemical composition and phase structure of adsorbents were characterized by X–Ray fluorescence spectroscopy (XRF) and X–ray diffraction (XRD), respectively. The morphology and disperse energy of the elements were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The functional group was identified by Fourier transform infrared spectroscopy (FT–IR). The efficiency of adsorption of H2S gas was studied. H2S gas in this study was synthesized by the chemical reaction between sodium sulfide (Na2S) and sulfuric acid (H2SO4). The concentration of hydrogen sulfide was measured by an H2S gas detector. The performance of the modified diatomite and leonardite for adsorption of H2S was compared. It was found that modified diatomite has better efficiency than modified leonardite for the adsorption of H2S gas. After modification process, the adsorption efficiency increased while the adsorption time decreased.

Preparation and Analysis of Kaolinite Intercalated by Potassium Acetate

2010 ◽  
Vol 150-151 ◽  
pp. 1220-1224
Author(s):  
Xiao Man Du ◽  
Qin Fu Liu ◽  
Hong Fei Cheng
Keyword(s):  
Thermal Analysis ◽  
Electron Microscope ◽  
Fourier Transformation ◽  
Potassium Acetate ◽  
Basal Spacing ◽  
X Ray Diffraction ◽  
Immersion Method ◽  
X Ray ◽  
Ft Ir ◽  
Scanning Electron

The kaolinite-potassium acetate composite was prepared by the immersion method. The intercalation composites were characterized by means of Scanning Electron Microscope (SEM), X-ray diffraction (XRD), Fourier transformation infrared (FT-IR) and High-resolution thermogravimetric analysis (HRTG). The results of XRD show that the intercalation of kaolinite by potassium acetate causes an increase of the basal spacing from 0.718 to 1.42nm. Thermal analysis shows the dehydroxylation of kaolinite decreased from 464 °C to 459.5 °C after intercalation of potassium acetate and three endotherms at 280, 323 and 459.5 °C attributed to the loss of water in the composite, potassium acetate and hydroxyl in the composite.

Fourier Transformation Infrared Spectrum Characteristics of Synthetic Zeolite A

2013 ◽  
Vol 591 ◽  
pp. 12-15
Author(s):  
Xiao Hu Zhang ◽  
Chun Ying Zhang ◽  
Feng Zhan ◽  
Nan Chun Chen
Keyword(s):  
Infrared Spectrum ◽  
Fourier Transformation ◽  
Synthetic Zeolite ◽  
Raw Material ◽  
Zeolite A ◽  
X Ray Diffraction ◽  
Natural Materials ◽  
X Ray ◽  
Ft Ir ◽  
Spectrum Characteristics

Synthesis of zeolite A by the use of natural materials (naturally stellerite) has been achieved without template agent. The final product was tested with X-ray diffraction, which was identified as the zeolite A. Then, the raw material and each step product were tested with Fourier Transformation Infrared (FT-IR). Comparing their FT-IR, we analyzed their spectrum characteristics, differences and reasons.

Study on Preparation of SiO2 Optical Fiber Preform by SG Method

2011 ◽  
Vol 299-300 ◽  
pp. 489-492
Author(s):  
Hui Tang ◽  
Ji Peng Zhang ◽  
Feng Gu ◽  
Feng Chun Wang ◽  
Ji Hua Wang
Keyword(s):  
Heat Treatment ◽  
Optical Fiber ◽  
Sol Gel ◽  
Amorphous Structure ◽  
Parent Material ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Fiber Preform ◽  
X Ray ◽  
Ft Ir

SiO2 optical fiber preform, the parent material in manufacturing optical fiber, plays an important role in the properties of optical fiber. In this paper, SiO2 dry gel was prepared by Sol-Gel method. According to this method, the gel was formed by hydrolyzing tetraethyl orthosilicate(TEOS) with hydrochloric acid and ammonia water, and the SiO2 dry gel was obtained by heat treatment of the gel at different temperature. The structure of the dry gel as prepared was characterized by X-ray Diffraction(XRD), Fourier Transform Infrared Spectroscopy(FT-IR) and Scanning electron microscope(SEM). As a result, amorphous structure is proved. Meanwhile, microscopic cracks are found to be decreased by adding formamide and increased when the heat-treatment temperature is above 75°C.

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