Moisture Effect on Structure and Mechanical Property of Nylon 6 as Studied by the Time-Resolved and Simultaneous Measurements of FT-IR and Dynamic Viscoelasticity under the Controlled Humidity at Constant Scanning Rate

AbstractZeolite morphology is crucial in determining their catalytic activity, selectivity and stability, but quantitative descriptors of such a morphology effect are challenging to define. Here we introduce a descriptor that accounts for the morphology effect in the catalytic performances of H-ZSM-5 zeolite for C4 olefin catalytic cracking. A series of H-ZSM-5 zeolites with similar sheet-like morphology but different c-axis lengths were synthesized. We found that the catalytic activity and stability is improved in samples with longer c-axis. Combining time-resolved in-situ FT-IR spectroscopy with molecular dynamics simulations, we show that the difference in catalytic performance can be attributed to the anisotropy of the intracrystalline diffusive propensity of the olefins in different channels. Our descriptor offers mechanistic insight for the design of highly effective zeolite catalysts for olefin cracking.

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Synthesis, Biomacromolecular Interactions, Photodynamic NO Releasing and Cellular Imaging of Two [RuCl(qn)(Lbpy)(NO)]X Complexes

Molecules ◽

10.3390/molecules26092545 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2545

Author(s):

Luna Song ◽

Hehe Bai ◽

Chenyang Liu ◽

Wenjun Gong ◽

Ai Wang ◽

...

Keyword(s):

Mass Spectrometry ◽

Confocal Imaging ◽

Epr Spectra ◽

Distorted Octahedral Geometry ◽

Ionization Mass ◽

Time Resolved ◽

Pbr322 Dna ◽

Vis Spectroscopy ◽

No Release ◽

Ft Ir

Two light-activated NO donors [RuCl(qn)(Lbpy)(NO)]X with 8-hydroxyquinoline (qn) and 2,2′-bipyridine derivatives (Lbpy) as co-ligands were synthesized (Lbpy1 = 4,4′-dicarboxyl-2,2′-dipyridine, X = Cl− and Lbpy2 = 4,4′-dimethoxycarbonyl-2,2′-dipyridine, X = NO3−), and characterized using ultraviolet–visible (UV-vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (1H NMR), elemental analysis and electrospray ionization mass spectrometry (ESI-MS) spectra. The [RuCl(qn)(Lbpy2)(NO)]NO3 complex was crystallized and exhibited distorted octahedral geometry, in which the Ru–N(O) bond length was 1.752(6) Å and the Ru–N–O angle was 177.6(6)°. Time-resolved FT-IR and electron paramagnetic resonance (EPR) spectra were used to confirm the photoactivated NO release of the complexes. The binding constant (Kb) of two complexes with human serum albumin (HSA) and DNA were quantitatively evaluated using fluorescence spectroscopy, Ru-Lbpy1 (Kb~106 with HSA and ~104 with DNA) had higher affinity than Ru-Lbpy2. The interactions between the complexes and HSA were investigated using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) and EPR spectra. HSA can be used as a carrier to facilitate the release of NO from the complexes upon photoirradiation. The confocal imaging of photo-induced NO release in living cells was successfully observed with a fluorescent NO probe. Moreover, the photocleavage of pBR322 DNA for the complexes and the effect of different Lbpy substituted groups in the complexes on their reactivity were analyzed.

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Diffusion Measurements Using FT-IR ATR Spectroscopy: Lubricant Diffusion in Polypropylene

Applied Spectroscopy ◽

10.1366/0003702021954962 ◽

2002 ◽

Vol 56 (4) ◽

pp. 509-514 ◽

Cited By ~ 3

Author(s):

Xiaohua Yi ◽

Karen Nerbonne ◽

John Pellegrino

Keyword(s):

Current Model ◽

Mineral Oil ◽

Attenuated Total Reflection ◽

Lubricant Layer ◽

Polymer Interfaces ◽

Time Resolved ◽

Polymer Sample ◽

Ft Ir ◽

Atr Spectroscopy ◽

Poly Propylene

We present an experimental method for measuring diffusion of lubricants (or any highly viscous fluid) in polymers using Fourier transform infrared (FT-IR) attenuated total reflection (ATR) spectroscopy. Unlike the conventional FT-IR ATR diffusion measurement, in which a polymer sample is sandwiched between the penetrant and an internal reflection element (IRE), in this method, a thin layer of penetrant (for example, a lubricant) is sandwiched between the IRE and the polymer sample. This allows accurate control and measurement of the thickness of the lubricant layer, which, in turn, facilitates subsequent data analysis. The diffusion is studied by monitoring the time-resolved change in absorbance of either a unique polymer or penetrant band. A feature of this new method is that it can provide an estimate of solubility, as well as an estimate of the diffusivity of the penetrant in the polymer. Using this method, we studied the diffusion of mineral oil and a commercial fluorocarbon ether lubricant (Krytox® 143AC‡) in poly(propylene) (PP) film at room temperature. The experimental data was modeled using a Fickian model with impermeable and saturated boundary conditions applied at the IRE/lubricant and lubricant/polymer interfaces, respectively. The diffusivity and solubility of mineral oil in PP were found to be 1.34 ± 0.35 (×10−10) cm2/s and 0.77 ± 0.13 (×10−2) g/g of PP, respectively. The current model was unable to quantitatively describe the diffusion of the Krytox® 143AC in the PP, possibly due to excessive swelling.

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Rapid-Scan Time-Resolved FT-IR Spectroelectrochemistry Studies on the Electrochemical Redox Process

The Journal of Physical Chemistry B ◽

10.1021/jp0666129 ◽

2007 ◽

Vol 111 (7) ◽

pp. 1517-1522 ◽

Cited By ~ 17

Author(s):

Baokang Jin ◽

Peng Liu ◽

Ye Wang ◽

Zipin Zhang ◽

Yupeng Tian ◽

...

Keyword(s):

Redox Process ◽

Time Resolved ◽

Rapid Scan ◽

Scan Time ◽

Ft Ir ◽

Electrochemical Redox

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Using the FT-IR linear dichroism method for molecular order determination of tendon collagen bundles and nylon 6

Acta Histochemica ◽

10.1016/j.acthis.2013.02.002 ◽

2013 ◽

Vol 115 (7) ◽

pp. 686-691 ◽

Cited By ~ 10

Author(s):

Benedicto de Campos Vidal

Keyword(s):

Linear Dichroism ◽

Nylon 6 ◽

Molecular Order ◽

Ft Ir ◽

Order Determination ◽

Tendon Collagen

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Guest-Host Inclusion Complex Formation of 2-, 3-, and 4-Aminobenzoic Acids with Native and Modified Cyclodextrins

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.69.10 ◽

2016 ◽

Vol 69 ◽

pp. 10-21 ◽

Cited By ~ 1

Author(s):

Narayanasamy Rajendiran ◽

J. Thulasidhasan ◽

M. Jude Jenita

Keyword(s):

Inclusion Complex ◽

Inclusion Complexation ◽

Aminobenzoic Acid ◽

Time Resolved ◽

H Nmr ◽

Buffer Solutions ◽

Aminobenzoic Acids ◽

Modified Cyclodextrins ◽

Ft Ir ◽

Uv Visible

The inclusion complexation of 2-aminobenzoic acid (2ABA), 3-aminobenzoic acid (3ABA), and 4-aminobenzoic acid (4ABA) with α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), hydroxypropyl-α-cyclodextrin (HP-α-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) were studied in buffer solutions of differentpHs (pH~1 andpH~7) and it was carried out using UV-Visible, steady-state and time-resolved fluorescence. Dual fluorescence was observed for all the compounds in aqueous and CD medium. All the ABAs forms 1:1 inclusion complex at pH ~ 1 solution and mixture of 1:1 and 1:2 inclusion complex at pH ~7. With CDs, dual luminescence appeared at pH ~ 1 indicates, both NH3+and COOH groups are present in the interior of the CDs cavities. FT-IR,1H NMR, results suggest ABAs formed a stable inclusion complex with the CDs.

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