Sol-, Gel-, and Paper-Based Detection of Picric Acid at Femtogram Level by a Short Peptide Gelator

Abstract Nanoporous carbon matrix was prepared by the sol-gel process from pyrogallol-formaldehyde (PF) mixtures in water using picric acid as catalyst. For the second sample, nickel oxide nanoparticles were added in the PF matrix to get a PF/NiO hybrid nanocomposite. The samples were heat treated at the pyrolysis temperature of 650°C for two hours. The obtained materials have been characterized by different techniques such as: X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential thermalanalysis (DTA),nitrogen adsorption-desorption isotherms, voltage-current characteristics, electrochemical measurementsand UV-Vis-IR absorption. The XRD analysis shows that PF matrix is amorphous while PF/NiO nanocomposite exhibited a metallic phase of nickel. The SEM and TEM images indicated the presence of nickel particles in the PF/NiO nanocomposite which are dispersed randomly in the carbon matrix. The adsorption-desorption of nitrogen revealed that the PF matrix is microporous and the PF/NiO nanocomposite is mesoporous. The adsorption capacities of carbon dioxide (CO2) and methane (CH4) show that the PF matrix has the highest adsorption at low pressures and the PF/NiO nanocomposite tends to adsorb gases better at high pressure. The V(I) characteristics showed that the PF/NiO nanocomposite can be considered as a smart material. Indeed, the characteristic behavior can be adjusted according to the maximum applied current. Electrochemical measurements have shown that the PF/NiO nanocomposite is very promising for the detection of non-enzymatic glucose. The absorption spectra showed that the addition of the NiO nanoparticles increased the disorder. The obtained materials are promoters for various applications such as gas storage, negatronic devices and glucose sensor.

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Proton transfer assisted facile encapsulation of picric acid in sol-gel derived silica decorated with azo-azomethine hosts

Dyes and Pigments ◽

10.1016/j.dyepig.2016.12.060 ◽

2017 ◽

Vol 139 ◽

pp. 635-643 ◽

Cited By ~ 10

Author(s):

Ruchi Mutneja ◽

Raghubir Singh ◽

Varinder Kaur ◽

Jörg Wagler ◽

Edwin Kroke ◽

...

Keyword(s):

Proton Transfer ◽

Picric Acid ◽

Sol Gel

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Cholesterol linked benzothiazole: a versatile gelator for detection of picric acid and metal ions such as Ag+, Hg2+, Fe3+ and Al3+ under different conditions

New Journal of Chemistry ◽

10.1039/c9nj01282f ◽

2019 ◽

Vol 43 (26) ◽

pp. 10509-10516 ◽

Cited By ~ 5

Author(s):

Subhendu Mondal ◽

Rameez Raza ◽

Kumaresh Ghosh

Keyword(s):

Metal Ions ◽

Picric Acid ◽

Sol Gel

The interaction of compound 1 with nitrophenols and metal ions has been studied in sol–gel medium. The nitrobenzene gel selectively recognizes picric acid, Ag+ and Hg2+ ions. In CH3CN, compound 1 further shows affinity towards Fe3+, Al3+ and Hg2+.

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Partial carbonized nanoporous resin for uptake of lead from aqueous solution

Water Science & Technology ◽

10.2166/wst.2015.298 ◽

2015 ◽

Vol 72 (6) ◽

pp. 974-982 ◽

Cited By ~ 2

Author(s):

I. Ghiloufi ◽

A. S. AL-Hobaib ◽

L. El Mir

Keyword(s):

Electron Microscopy ◽

Aqueous Solution ◽

Metal Ion ◽

Picric Acid ◽

Sol Gel ◽

The Other ◽

Ion Concentration ◽

Order Kinetic ◽

Effective Parameters ◽

Lead Uptake

Four partial carbonized nanoporous resins (PCNRs), based on organic xerogel compounds, were synthesised by the sol–gel method from pyrogallol and formaldehyde mixtures in water using picric acid as catalyst. The PCNRs were prepared at different pyrolysis temperatures: T1 = 200 °C (PF-200), T2 = 300 °C (PF-300), T3 = 400 °C (PF-400), or T4 = 500 °C (PF-500). The PCNRs were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transformed infrared spectroscopy, and nitrogen porosimetry. The obtained results show that PF-200 is more efficient for the removal of Pb2+ from aqueous solution than the other adsorbent prepared in this study. The characteristics of lead uptake by PF-200 were explored using well-established and effective parameters including pH, contact time, initial metal ion concentration and temperature. Optimum adsorption of Pb2+, using PF-200, was observed at pH 4.5. The Langmuir model gave a better fit than the other models, and kinetic studies revealed that the adsorption was well fitted by the pseudo second-order kinetic model and thermodynamic properties, i.e., Gibbs free energy change, enthalpy change and entropy change, showed that adsorption of Pb2+ onto PF-200 was endothermic, spontaneous and feasible in the temperature range of 298–328 K.

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The Ultrastructure of Myocardial Cells in Normal and Cardiac Lethal Mutant Mexican Axolotls, (Ambystoma Mexicanum)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100067303 ◽

1970 ◽

Vol 28 ◽

pp. 62-63

Author(s):

Larry F. Lemanski ◽

Eldridge M. Bertke ◽

J. T. Justus

Keyword(s):

Fine Structure ◽

Heart Development ◽

Osmium Tetroxide ◽

Picric Acid ◽

Ambystoma Mexicanum ◽

Recessive Mutation ◽

Acid Mixture ◽

Myocardial Cells ◽

Lethal Mutant ◽

Mexican Axolotl

A recessive mutation has been recently described in the Mexican Axolotl, Ambystoma mexicanum; in which the heart forms structurally, but does not contract (Humphrey, 1968. Anat. Rec. 160:475). In this study, the fine structure of myocardial cells from normal (+/+; +/c) and cardiac lethal mutant (c/c) embryos at Harrison's stage 40 was compared. The hearts were fixed in a 0.1 M phosphate buffered formaldehyde-glutaraldehyde-picric acid-styphnic acid mixture and were post fixed in 0.1 M s-collidine buffered 1% osmium tetroxide. A detailed study of heart development in normal and mutant embryos from stages 25-46 will be described elsewhere.

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TEM visualization of surface replicated acid and base catalyzed sol-gel glasses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010014381x ◽

1986 ◽

Vol 44 ◽

pp. 448-449

Author(s):

George C. Ruben ◽

Merrill W. Shafer

Keyword(s):

Elevated Temperatures ◽

Sol Gel ◽

Basic Medium ◽

Glass Transition Point ◽

Structural Space ◽

Acid And Base ◽

Organometallic Precursors ◽

New Processing ◽

Gel Glasses ◽

Physical Phenomena

Traditionally ceramics have been shaped from powders and densified at temperatures close to their liquid point. New processing methods using various types of sols, gels, and organometallic precursors at low temperature which enable densificatlon at elevated temperatures well below their liquidus, hold the promise of producing ceramics and glasses of controlled and reproducible properties that are highly reliable for electronic, structural, space or medical applications. Ultrastructure processing of silicon alkoxides in acid medium and mixtures of Ludox HS-40 (120Å spheres from DuPont) and Kasil (38% K2O &62% SiO2) in basic medium have been aimed at producing materials with a range of well defined pore sizes (∼20-400Å) to study physical phenomena and materials behavior in well characterized confined geometries. We have studied Pt/C surface replicas of some of these porous sol-gels prepared at temperatures below their glass transition point.

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Electron microscopy studies of PZT ferroelectric film capacitor structures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131450 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1364-1365

Author(s):

V. Kaushik ◽

P. Maniar ◽

J. Olowolafe ◽

R. Jones ◽

A. Campbell ◽

...

Keyword(s):

Electric Fields ◽

Sol Gel ◽

Ferroelectric Material ◽

Dielectric Constants ◽

Dielectric Films ◽

Lead Zirconium Titanate ◽

Si Substrate ◽

Film Capacitor ◽

Pzt Films ◽

High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

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The crystallization of thin-film ceramics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122095 ◽

1992 ◽

Vol 50 (1) ◽

pp. 338-339

Author(s):

J.M. Schwartz ◽

L.F. Francis ◽

L.D. Schmidt ◽

P.S. Schabes-Retchkiman

Keyword(s):

Thin Films ◽

Grain Size ◽

Sol Gel ◽

Processing Route ◽

Small Areas ◽

Ceramic Thin Films ◽

Complex Shapes ◽

Sol Gel Process ◽

Ceramic Precursors ◽

Crystalline Ceramic

Ceramic thin films and coatings are of interest for electrical, optical, magnetic and thermal barrier applications. Critical for improved properties in thin films is the development of specific microstructures during processing. To this end, the sol-gel method is advantageous as a versatile processing route. The sol-gel process involves depositing a solution containing metalorganic or colloidal ceramic precursors onto a substrate and heating the deposited layer to form a crystalline or non-crystalline ceramic coating. This route has several advantages, including the ability to create tailored microstructures and properties, to coat large or small areas, simple or complex shapes, and to more easily prepare multicomponent ceramics. Sol-gel derived coatings are amorphous in the as-deposited state and develop their crystalline structure and microstructure during heat-treatment. We are particularly interested in studying the amorphous to crystalline transformation, because many key features of the microstructure such as grain size and grain size distribution may be linked to this transformation.

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The use of high-resolution FESEM to study solid-state phase transformations and reactions

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100172875 ◽

1994 ◽

Vol 52 ◽

pp. 1028-1029

Author(s):

P. G. Kotula ◽

D. D. Erickson ◽

C. B. Carter

Keyword(s):

Solid State ◽

High Resolution ◽

Phase Transformations ◽

High Efficiency ◽

Sol Gel ◽

Quantitative Information ◽

Solid State Reactions ◽

Critical Dimensions ◽

Backscattered Electrons ◽

Backscattered Electron

High-resolution field-emission-gun scanning electron microscopy (FESEM) has recently emerged as an extremely powerful method for characterizing the micro- or nanostructure of materials. The development of high efficiency backscattered-electron detectors has increased the resolution attainable with backscattered-electrons to almost that attainable with secondary-electrons. This increased resolution allows backscattered-electron imaging to be utilized to study materials once possible only by TEM. In addition to providing quantitative information, such as critical dimensions, SEM is more statistically representative. That is, the amount of material that can be sampled with SEM for a given measurement is many orders of magnitude greater than that with TEM.In the present work, a Hitachi S-900 FESEM (operating at 5kV) equipped with a high-resolution backscattered electron detector, has been used to study the α-Fe2O3 enhanced or seeded solid-state phase transformations of sol-gel alumina and solid-state reactions in the NiO/α-Al2O3 system. In both cases, a thin-film cross-section approach has been developed to facilitate the investigation. Specifically, the FESEM allows transformed- or reaction-layer thicknesses along interfaces that are millimeters in length to be measured with a resolution of better than 10nm.

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