FTIR and UV-Visible Absorbance Studies of Hydrothermally Grown ZnO Coated with Polyvinylpyrrolidone

2017 ◽  
Vol 895 ◽  
pp. 73-78
Author(s):  
Verdad C. Agulto ◽  
Ian Jasper Agulo ◽  
Roland V. Sarmago

Hydrothermally grown hexagonal wurtzite ZnO microrods coated with polyvinylpyrrolidone (PVP) via an ex-situ method, was successfully synthesized without using complex procedure or experimental setup. FTIR results confirm the presence of different functional groups of PVP at the ZnO surface and the chemical interaction of ZnO with the C=O ligand of the PVP molecule. The presence of PVP molecules prevents the absorption of atmospheric CO2 by the Zn2+ ions since PVP chemically interacts with ZnO by attaching to the exposed cations. The coating concentration doesn’t induce a frequency shift in the vibrations of the PVP functional groups. The ZnO microrods possess good optical quality as indicated by the high UV absorption and pronounced excitonic peak at room temperature, even after coating with higher PVP concentrations.

MRS Advances ◽  
2017 ◽  
Vol 2 (62) ◽  
pp. 3891-3897 ◽  
Author(s):  
Francisco G. Granados-Martínez ◽  
Diana L. García-Ruiz ◽  
José J. Contreras-Navarrete ◽  
Jael M. Ambriz-Torres ◽  
Carmen J. Gutiérrez-García ◽  
...  

ABSTRACTThe aim of this research is to ameliorate the dispersion of pristine and functionalized Carbon Nanotubes (CNTs) into polystyrene with hydroxyl end groups (PSOH) matrices using low magnetic fields. The Multi-Walled Carbon Nanotubes (MWCNTs) were synthesized by chemical vapor deposition (CVD) using benzene as carbon source; to produce CNTs with and without functional groups two catalysts were used (stainless steel and ferrocene). The obtained nanotubes contained iron nanoparticles inside. PSOH were synthesized using styrene as monomer, azobisisobutyronitrile as initiator and 2-MeOH as chain transfer agent. The MWCNTs-PSOH matrices were formed using 1.6 wt % of carbon nanotubes into PSOH and ultrasonic mixing for 30 min. The mixing materials were poured into containers and dry at room temperature. While the material was drying, constant magnetic fields of 0.24 T were being applied for 50 min. The MWCNTs-PSOH composites were analysed by SEM, FTIR and Raman spectroscopy. SEM micrographs showed that MWCNTs without functional groups were incorporated in the middle of PSOH. The MWCNTs functionalized perform differently; a better dispersion through the entire polymer matrix was achieved, because the polymer embedded the CNTs. FTIR and Raman spectroscopy showed chemical interaction between PSOH and MWCNTs functionalized. The CNTs dispersion into PSOH was ameliorated through the use of low magnetic fields and functionalization.


1993 ◽  
Vol 329 ◽  
Author(s):  
Michael Canva ◽  
Patrick Georges ◽  
Jean-Fran^ois Perelgritz ◽  
Alain Brun ◽  
Fréddric Chaput ◽  
...  

AbstractPhotoresistant laser dyes were trapped in silica based xerogel host matrices to obtain solid state tunable lasers. For this purpose very dense xerogel samples with improved chemical and physical properties were prepared at room temperature by the sol-gel technology. The as-prepared materials were polished to obtain optical quality surfaces and were used as new lasing media.Lasing action of such different dyes as rhodamine, perylene and pyrromethene doping dense sol-gel matrices was demonstrated. Efficiencies of 30 % or lifetimes of more than 100,000 shots were achieved with different new ≤dye dopant/host matrix≥ couples. Their different performances are reviewed and discussed.


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 623
Author(s):  
Monika Gupta ◽  
Huzein Fahmi Hawari ◽  
Pradeep Kumar ◽  
Zainal Arif Burhanudin ◽  
Nelson Tansu

The demand for carbon dioxide (CO2) gas detection is increasing nowadays. However, its fast detection at room temperature (RT) is a major challenge. Graphene is found to be the most promising sensing material for RT detection, owing to its high surface area and electrical conductivity. In this work, we report a highly edge functionalized chemically synthesized reduced graphene oxide (rGO) thin films to achieve fast sensing response for CO2 gas at room temperature. The high amount of edge functional groups is prominent for the sorption of CO2 molecules. Initially, rGO is synthesized by reduction of GO using ascorbic acid (AA) as a reducing agent. Three different concentrations of rGO are prepared using three AA concentrations (25, 50, and 100 mg) to optimize the material properties such as functional groups and conductivity. Thin films of three different AA reduced rGO suspensions (AArGO25, AArGO50, AArGO100) are developed and later analyzed using standard FTIR, XRD, Raman, XPS, TEM, SEM, and four-point probe measurement techniques. We find that the highest edge functionality is achieved by the AArGO25 sample with a conductivity of ~1389 S/cm. The functionalized AArGO25 gas sensor shows recordable high sensing properties (response and recovery time) with good repeatability for CO2 at room temperature at 500 ppm and 50 ppm. Short response and recovery time of ~26 s and ~10 s, respectively, are achieved for 500 ppm CO2 gas with the sensitivity of ~50 Hz/µg. We believe that a highly functionalized AArGO CO2 gas sensor could be applicable for enhanced oil recovery, industrial and domestic safety applications.


2008 ◽  
Vol 47 (1) ◽  
pp. 109-112 ◽  
Author(s):  
Ye-Rim Yeon ◽  
Young Jun Park ◽  
Ji-Sung Lee ◽  
Jung-Woo Park ◽  
Sin-Gun Kang ◽  
...  

2011 ◽  
Vol 121-126 ◽  
pp. 493-498 ◽  
Author(s):  
Huei Ruey Ong ◽  
Reddy Prasad ◽  
Md. Maksudur Rahman Khan ◽  
Md. Najmul Kabir Chowdhury

Increased demand for wood adhesives, environmental concerns, and the uncertainty of continuing availability of petrochemicals have led to recent attention on protein-based adhesives. This study was conducted to investigate the physico-chemical interaction of palm kernel meal (PKM) with melamine urea formaldehyde (MUF) resins in adhesive formulation by using Fourier Transform Infrared (FTIR) Spectroscopy. The effect of hot press on PKM extender has been investigated by FTIR and blue shift is observed due to the hot press indicating that the functional groups (such as C=O, -OH and NH) are become more free in the samples. In the case of PKM-MUF blend bonding interactions observed where, PKM played the role as an extender. Red shift of C=O and N-H groups stretching in PKM-MUF-Wood blend is observed which suggests the interaction of these functional groups through hydrogen bonding. The results suggest that PKM extender-based MUF adhesive resins have potential application for the production of exterior plywood.


2021 ◽  
Author(s):  
Zhongyan Chen ◽  
Lepeng Chen ◽  
Shou-Feng Zhang ◽  
Qianqian Zhen ◽  
Wenzhang Xiong ◽  
...  

A nickel-catalyzed synthesis of 1,3-diaryl-6H-pyrazino[2,1-b]quinazolin-6-one was developed. This method enabled to access valuable pyrazino-fused quinazolinones with tolerance of many functional groups even at room temperature. The desired pyrazino-fused quinazolinones emit...


Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 202
Author(s):  
Miranda Martinez ◽  
Anil R. Chourasia

The Ti/SnO2 interface has been investigated in situ via the technique of x-ray photoelectron spectroscopy. Thin films (in the range from 0.3 to 1.1 nm) of titanium were deposited on SnO2 substrates via the e-beam technique. The deposition was carried out at two different substrate temperatures, namely room temperature and 200 °C. The photoelectron spectra of tin and titanium in the samples were found to exhibit significant differences upon comparison with the corresponding elemental and the oxide spectra. These changes result from chemical interaction between SnO2 and the titanium overlayer at the interface. The SnO2 was observed to be reduced to elemental tin while the titanium overlayer was observed to become oxidized. Complete reduction of SnO2 to elemental tin did not occur even for the lowest thickness of the titanium overlayer. The interfaces in both the types of the samples were observed to consist of elemental Sn, SnO2, elemental titanium, TiO2, and Ti-suboxide. The relative percentages of the constituents at the interface have been estimated by curve fitting the spectral data with the corresponding elemental and the oxide spectra. In the 200 °C samples, thermal diffusion of the titanium overlayer was observed. This resulted in the complete oxidation of the titanium overlayer to TiO2 upto a thickness of 0.9 nm of the overlayer. Elemental titanium resulting from the unreacted overlayer was observed to be more in the room temperature samples. The room temperature samples showed variation around 20% for the Ti-suboxide while an increasing trend was observed in the 200 °C samples.


2019 ◽  
Vol 2 (1) ◽  
pp. 50
Author(s):  
Andrie Harmaji ◽  
Claudia Claudia ◽  
Lia Asri ◽  
Bambang Sunendar ◽  
Ahmad Nuruddin

Abstract:. Suralaya power plant produces fly ash about 219.000 ton per year. Fly ash contents of silica and alumina as major components that can be used as precursors for geopolymer, a three dimensional networks aluminosilicate polymers. This research aim is to utilize fly ash for geopolymer made by mixing fly ash, fine aggregate, and alkali activator in a cubic mould and curing was carried out at room temperature for 7 and 28 days. After 28 days of curing the compressive strength of geopolymer reached 41.70 MPa. XRD characterization shows Albite (NaAlSi3O8) formation which has similarity to geopolymer compound. Fourier Transform Infra Red spectra show siloxo and sialate bond. These are typical functional groups that are found in geopolymer materials.Keyword: geopolymer, fly ash, aluminosilicate, alkali activator, albite, siloxo, sialateAbstrak: Pembangkit Listrik Tenaga Uap (PLTU) Suralaya menghasilkan fly ash (abu terbang) sekitar 219.000 ton per tahun. Fly ash memiliki silika dan alumina sebagai komponen utama yang dapat digunakan sebagai prekursor untuk geopolimer, suatu material polimer aluminosilikat tiga dimensi. Penelitian ini bertujuan untuk memanfaatkan fly ash untuk geopolimer yang dibuat dengan mencampur fly ash, agregat halus, dan aktivator alkali dalam cetakan kubik dan pengawetan dilakukan pada suhu kamar selama 7 dan 28 hari. Setelah 28 hari curing kekuatan tekan geopolimer mencapai 41,70 MPa. Karakterisasi XRD menunjukkan pembentukan Albite (NaAlSi3O8) yang memiliki kemiripan dengan senyawa geopolimer. Hasil spektroskopi Fourier Transform Infra Red (FTIR) menunjukkan ikatan siloxo dan sialate yang merupakan gugus fungsional khas yang ditemukan dalam geopolimer.Kata Kunci: geopolimer, abu terbang, aluminosilikat, alkali aktivator, albite, siloxo, sialate


2011 ◽  
Vol 8 (4) ◽  
pp. 1005-1011
Author(s):  
Baghdad Science Journal

Many complexes of 3,5-dimethyl-1H-pyrazol-1-yl phenyl methanone with Cr(III), Co(II), Ni(II), Cu(II) and Cd(II) were synthesized and characterized by FT-IR, UV/visible spectra, elemental analysis, room temperature magnetic susceptibility and molar conductivity. Cd(II) complex was expected to have tetrahedral structure while all the other complexes were expected to have an octahedral structure.


2020 ◽  
pp. 44-52
Author(s):  
Ahmed Ahmed S. Abed ◽  
Sattar J. Kasim ◽  
Abbas F. Abbas

In the present study, the microwave heating method was used to prepare cadmium sulfide quantum dots CdSQDs films. CdS nanoparticles size average obtained as (7nm). The morphology, structure and composition of prepared CdSQDs were examined using (FE-SEM), (XRD) and (EDX). Optical properties of CdSQDs thin films formed and deposited onto glass substrates have been studied at room temperature using UV/ Visible spectrophotometer within the wavelength of (300-800nm), and Photoluminescence (PL) spectrum. The optical energy gap (Eg) which estimated using Tauc relation was equal (2.6eV). Prepared CdS nanoparticles thin films are free from cracks, pinholes and have high adhesion to substrate.


Sign in / Sign up

Export Citation Format

Share Document