scholarly journals Mechanism of Thermal Degradation-Induced Gel Formation in Polyamide 6/Ethylene Vinyl Alcohol Blend Nanocomposites Studied by Time-Resolved Rheology and Hyphenated Thermogravimetric Analyzer Fourier Transform Infrared Spectroscopy Mass Spectroscopy: Synergistic Role of Nanoparticles and Maleic-anhydride-Grafted Polypropylene

ACS Omega ◽  
2019 ◽  
Vol 4 (5) ◽  
pp. 9569-9582 ◽  
Author(s):  
Reza Salehiyan ◽  
Jayita Bandyopadhyay ◽  
Suprakas Sinha Ray
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Maleic Anhydride ◽  
Polyamide 6 ◽  
Gel Formation ◽  
Time Resolved ◽  
Ethylene Vinyl Alcohol ◽  
Thermogravimetric Analyzer ◽  
Blend Nanocomposites

Dependence of the intrinsic phase structure of Bi2O3 catalysts on photocatalytic CO2 reduction

2021 ◽  
Vol 11 (6) ◽  
pp. 2021-2025
Author(s):  
Liujin Wei ◽  
Guan Huang ◽  
Yajun Zhang
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Phase Structure ◽  
Co2 Reduction ◽  
Fourier Transform Infrared ◽  
Time Resolved ◽  
Dependent Activity

The combination of time-resolved transient photoluminescence with in-situ Fourier transform infrared spectroscopy has been conducted to investigate the intrinsic phase structure-dependent activity of Bi2O3 catalyst for CO2 reduction.

Real-Time Pursuit of Crystal Growth by Millisecond Time-Resolved Multichannel Fourier Transform Infrared Spectroscopy

1998 ◽  
Vol 52 (2) ◽  
pp. 222-225
Author(s):  
Mamoru Hashimoto ◽  
Hiro-O Hamaguchi
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Structural Change ◽  
Liquid Phase ◽  
Fourier Transform Infrared Spectroscopy ◽  
Molecular Orientation ◽  
Structural Changes ◽  
Fourier Transform Infrared ◽  
Time Resolved ◽  
Recovery Curves

The surface (about 130 molecular layers) of an oriented thin crystal of decanoic acid was subjected to sudden melting by a laser-induced temperature jump (T-jump), and the process of subsequent crystal re-growth was monitored by millisecond time-resolved multichannel Fourier transform infrared spectroscopy. The gauche–trans structural change of the alkane part of the molecule has been probed by the CH stretch bands in the 2800–3000 cm−1 region. The change in the molecular orientation has been detected by the OH stretch band around 3065 cm−1. The recovery curves for the CH2 antisymmetric stretch and the OH stretch bands are markedly different from each other in the first 200 ms, suggesting that the gauche–trans structural changes precedes the crystal re-growth. After 500 ms, the recovery curves become identical. This result means that the rate of the gauche to the trans structural change is equal to the rate of the recovery of the molecular orientation. It is highly likely that a fast equilibrium is attained between the gauche and the trans conformations in the liquid phase after 500 ms from the sudden melting and that the crystal re-growth takes place solely via the all-trans structure in the liquid phase.

scholarly journals Probing the Proton-Loading Site of Cytochrome C Oxidase Using Time-Resolved Fourier Transform Infrared Spectroscopy

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3393
Author(s):  
Elena Gorbikova ◽  
Sergey A. Samsonov ◽  
Ruslan Kalendar
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Fourier Transform Infrared Spectroscopy ◽  
Paracoccus Denitrificans ◽  
Fourier Transform Infrared ◽  
Double Difference ◽  
Time Resolved ◽  
Fast Kinetic

Crystal structure analyses at atomic resolution and FTIR spectroscopic studies of cytochrome c oxidase have yet not revealed protonation or deprotonation of key sites of proton transfer in a time-resolved mode. Here, a sensitive technique to detect protolytic transitions is employed. In this work, probing a proton-loading site of cytochrome c oxidase from Paracoccus denitrificans with time-resolved Fourier transform infrared spectroscopy is presented for the first time. For this purpose, variants with single-site mutations of N131V, D124N, and E278Q, the key residues in the D-channel, were studied. The reaction of mutated CcO enzymes with oxygen was monitored and analyzed. Seven infrared bands in the “fast” kinetic spectra were found based on the following three requirements: (1) they are present in the “fast” phases of N131V and D124N mutants, (2) they have reciprocal counterparts in the “slow” kinetic spectra in these mutants, and (3) they are absent in “fast” kinetic spectra of the E278Q mutant. Moreover, the double-difference spectra between the first two mutants and E278Q revealed more IR bands that may belong to the proton-loading site protolytic transitions. From these results, it is assumed that several polar residues and/or water molecule cluster(s) share a proton as a proton-loading site. This site can be propionate itself (holding only a fraction of H+), His403, and/or water cluster(s).

scholarly journals Polypropylene grafted with maleic anhydride and styrene as a compatibilizer for biodegradable poly(propylene carbonate)/polypropylene

2019 ◽  
Vol 14 ◽  
pp. 155892501984971
Author(s):  
Zheng Tian ◽  
Lisha Pan ◽  
Qing Pan
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Maleic Anhydride ◽  
Fourier Transform Infrared Spectroscopy ◽  
Propylene Carbonate ◽  
Ring Opening ◽  
Fourier Transform Infrared ◽  
Resonance Spectroscopy ◽  
Ring Opening Reactions ◽  
Poly Propylene

Polypropylene grafted with maleic anhydride and styrene [PP- g-(MAH- co-St)] was prepared by melt grafting. Fourier transform-infrared spectroscopy showed that maleic anhydride in the form of cyclic anhydride was successfully grafted onto the main chains of polypropylene. PP- g-(MAH- co-St) acts as a compatibilizer for the poly(propylene carbonate)/polypropylene meltblown nonwoven fabric slices. The effect of different contents and grafting proportions of PP- g-(MAH- co-St) on the structure and performance of the poly(propylene carbonate)/polypropylene slices was investigated. The poly(propylene carbonate)/polypropylene slices had favorable compatibility, tensile properties, thermal stability, and degradability, and their melt flow rates were reduced by the addition of PP- g-(MAH- co-St). Fourier transform-infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy spectra showed that ring-opening reactions occur between the anhydride functional groups of PP- g-(MAH- co-St) and poly(propylene carbonate). Ring-opening reactions, chemical bonds, cocrystallization, increased interface adhesion forces, and reduced interfacial tension may be the mechanisms by which PP- g-(MAH- co-St) acts a compatibilizer for poly(propylene carbonate)/polypropylene slices.

Sign in / Sign up

Export Citation Format

Share Document