Selective Interactions in Elastomers, a Base for Compatibility and Polymer-Filler Interactions

1996 ◽  
Vol 69 (5) ◽  
pp. 769-780 ◽  
Author(s):  
R. H. Schuster ◽  
H. M. Issel ◽  
V. Peterseim
Keyword(s):  
Phase Inversion ◽  
Domain Size ◽  
Solubility Parameters ◽  
Polymer Filler ◽  
Average Domain Size ◽  
First Time ◽  
Average Domain ◽  
Selective Interactions

Abstract This paper describes the determination of accurate solubility parameters for nonpolar rubbers according to a GLC-method developed by Guillet. The data obtained provide a simple but meaningful thermodynamic characterization of the contribution of microstructure units and comonomers (styrene) in polydienes. On this basis quantitative expressions are derived for δ2-parameters of BR and SBR as a function of the vinyl and the styrene content respectively. The consequences on morphology development and miscibility are presented for blends of NR, SBR, BR and EPDM. Furthermore, it is shown for the first time that the method is able to describe the temperature dependence of the δ2-parameter so that temperature induced phase transitions (UCST and LCST) can be predicted. On this basis morphological predictions are made on average domain size and size distribution as well as on the phase inversion region. The contribution of intermolecular interactions to flow-induced phase morphology is discussed in relation to the influence of rheological factors. An extension to polymer—filler systems is made.

Determination of Lead Traces by Stripping Voltammetry Using Ti(N,C) Working Electrodes

2010 ◽  
Vol 65 ◽  
pp. 168-173
Author(s):  
Marta Ziemnicka ◽  
Bogusław Baś ◽  
Mateusz Jeż ◽  
Ludosław Stobierski
Keyword(s):  
Electron Microscopy ◽  
Electrode Surface ◽  
Stripping Voltammetry ◽  
Electrochemical Activation ◽  
Trace Metal Analysis ◽  
Response Performance ◽  
Disc Electrodes ◽  
First Time

Electrochemical stripping techniques still attract considerable attention for trace metal analysis and for measuring several important organic compounds, due to their unique capabilities of pre-concentrating the analytes at the electrode surface and associated favourable low limits of detection. In this work it is reported for the first time that the Ti(N0,1C0,9), Ti(N0,4C0,6) and Ti(N0,5C0,5) working disc electrodes, a „mercury-free” sensors, offers surprisingly good analytical performance and some valuable properties. The analytical applicability of the Ti(N,C) electrode was confirmed in determination of lead(II) traces in synthetic solutions both with and without surfactants, in certified reference material and in natural water samples. The effects of dissolved oxygen, acids, anions and metal ions were investigated for the Ti(N,C) electrode. Newly prepared and not activated electrode usually cannot be polarized. Therefore, to use the electrode as a voltammetric sensor, its electrochemical activation is required. Composition of conditioning electrolyte and procedures of the electrodes activation were optimized. The fabrication and the response performance of the investigated electrodes were described in the paper. The voltammetric data were associated with the structural characterization of the electrode surface using scanning electron microscopy (SEM) and transmition electron microscopy (TEM).

scholarly journals Antioxidant Activity and Characterization of One New Polysaccharide Obtained fromPerigord Truffle(Tuber huidongense)

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yong-Feng Chen ◽  
Wen-wen Jiang ◽  
Shi-qi Zhang ◽  
Jian-quan Kan ◽  
Yong Liang
Keyword(s):  
Molecular Structure ◽  
Antioxidant Activity ◽  
Structural Characteristics ◽  
Water Soluble ◽  
Separation And Purification ◽  
Edible Fungus ◽  
Main Components ◽  
First Time

As a medicinal and edible fungus parasitizing on the trees, Perigord Truffle (Tuber huidongense) is well known for its delicious taste, unique smell, and high medical value for healthcare. One new water-soluble nonstarch polysaccharide (PST-W with the yield of 0.41%) fromPerigord Truffle(Tuber huidongense) was purified and identified on structural characteristics for the first time. The characterizations of PST-W were studied on physicochemical properties, main components of monosaccharide(s), and molecular structure. The monosaccharide compositions of PST-W were studied and identified as glucan, only containing D-glucoses with the molecular structure of [→6)α-D-Glcp(1→6)  α-D-Glcp (1→]nby methylation analysis and NMR. In the determination of total reducing capacity, the reducing abilities of polysaccharide extracts could be listed as vitamin C > PST-W > crude polysaccharides-3 > crude polysaccharides-2 > crude polysaccharides-1. All of PST-W, crude polysaccharides-2, and crude polysaccharides-3 were relatively good scavenger for 1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl radicals with IC50of 2.81, 4.17, and 3.44 mg/mL, respectively. However,O2-∙clearing abilities of PST-W and crude polysaccharides were obviously weaker. The activities of total crude extract were the worst, indicating that the impurities might negatively affect the antioxidant activity. Thus, the separation and purification of polysaccharides were significant to increase the antioxidant activity in some degree.

Domain structure investigation of non-stoichiometric strontium ferrites and cobaltites

2013 ◽  
Vol 28 (S2) ◽  
pp. S51-S64 ◽  
Author(s):  
U.V. Ancharova ◽  
S.V. Cherepanova
Keyword(s):  
Domain Structure ◽  
Domain Size ◽  
Orthorhombic Distortion ◽  
Synchrotron Powder Diffraction ◽  
Structure Simulation ◽  
Average Domain Size ◽  
Xrd Patterns ◽  
Average Domain ◽  
Debye Equation ◽  
Strontium Ferrites

Monte Carlo domain structure simulation and Debye equation calculation of XRD patterns were used to confirm the formation of domain structure and investigate its peculiarities. Correspondence of simulated XRD patterns with synchrotron powder diffraction experiments is achieved on the conditions that beside of 90o rotations of brownmillerite-like domains inside perovskite-like matrix each domain contains areas with perpendicularly oriented tetrahedral chains. Influence of such parameters as stoichiometry, average domain size, orthorhombic distortion degree on the XRD patterns is considered.

Improvement of Wrinkles in Roll-to-Roll Microwave Plasma CVD Graphene

2015 ◽  
Vol 1761 ◽  
Author(s):  
Takatoshi Yamada ◽  
Nayuta Shimada ◽  
Kazuki Uekusa ◽  
Masataka Hasegawa
Keyword(s):  
Microwave Plasma ◽  
Chemical Vapor ◽  
Domain Size ◽  
Plasma Chemical Vapor Deposition ◽  
Roll To Roll ◽  
Graphene Films ◽  
Microwave Plasma Cvd ◽  
Average Domain Size ◽  
Conductive Properties ◽  
Average Domain

ABSTRACTWrinkle-less graphene films are obtained through roll-to-roll microwave plasma chemical vapor deposition by using flexible copper/polyimide (Cu/PI) webs. Raman spectra suggests that the average domain size of the obtained graphene on the flexible Cu/PI is almost the same compared to the graphene on a Cu web that includes wrinkles. Also, by utilizing the flexible Cu/PI webs, the compressive strains decreased. The sheet resistances of graphene deposited on the Cu/PI are (1∼5)×104Ω, which is two orders of magnitude lower than those of graphene deposited on the Cu webs. Our results suggest that the controlling the expansion of web material an important technology to improve graphene transparent conductive properties.

Characterization of 10 Biogenic Amines in Male Silkworm Moth by HPLC with Precolumn Derivatization

2020 ◽  
Vol 16 (5) ◽  
pp. 608-614
Author(s):  
Mingqin Fan ◽  
Yun Ai ◽  
Wenjie Zhao ◽  
Yanni Sun ◽  
Jianli Liu ◽  
...  
Keyword(s):  
Biogenic Amines ◽  
Biologically Active ◽  
Low Molecular Weight ◽  
Precolumn Derivatization ◽  
Mean Values ◽  
The Mean ◽  
Toxic Potential ◽  
First Time

Background: Biogenic Amines (BAs) are biologically active nitrogenous organic compounds of low molecular weight, which are frequently found in a wide variety of foods, beverages and herbs due to their toxic potential in humans. Male Silkworm Moth (MSM), a Traditional Chinese Medicine (TCM), has been exploited and utilized as nutritious liquor based on its traditional effects in the Chinese community. Objective: The objective of this study was to develop an HPLC with Dns-Cl derivatization method for characterizing overall BAs in MSM and providing data for further evaluating its activities and safety profiles. Methods: The method has acceptable sensitivity, precision, accuracy, selectivity and recovery, and was successfully applied to the determination of the BAs contents in MSM for the first time. Results: In the analysis of 10 batches of MSM samples, serotonin and dopamine were not found in detectable concentrations in any samples, and the most abundant amine found was putrescine. The mean values of tryptamine, phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine determined in the samples were found to be 34.7 mg/ kg, 16.1 mg/ kg, 218.3 mg/ kg, 37.9 mg/ kg, 12.1 mg/ kg, 18.2 mg/ kg, 4.5mg/ kg, and 0.9 mg/ kg, respectively. Conclusion: The contents of BAs in 10 batches of MSM were below the maximum recommended limits, and MSM can be used safely.

Determination of Phenolic Compounds in the Methanolic Extract of Pourouma guianensis Leaves by UPLC-DAD-MS

2020 ◽  
Vol 10 (5) ◽  
pp. 566-570
Author(s):  
Queitilane de S. Sales ◽  
Marcelo da S. Mathias ◽  
Rodrigo R. de Oliveira
Keyword(s):  
Phenolic Compounds ◽  
Formic Acid ◽  
Solvent System ◽  
Efficient Tool ◽  
Phenolic Substances ◽  
Chemical Knowledge ◽  
First Time ◽  
Southeastern Region

Background: The presence of phenolic compounds is common in Urticaceae. However, only one report of the isolation of an apigenin in the Pourouma genus is available. Pourouma guianensis occurs widely throughout Brazil, mainly in the Southeastern region, and is popularly known as “pitinga”. The chemical profile of P. guianensis is marked by the presence of steroids and triterpenes. Objective: This study carried out the characterization of phenolic substances using UPLC-DAD-MS separation, in order to increase the chemical knowledge on the Pourouma genus. Methods: The extract was analyzed by UPLC-DAD-MS using a C-18 column, DAD detector at 190- 400nm and ESI-Q-TOF mass spectrometer. The solvent system consisted of water with 0.1% formic acid (phase A) and acetonitrile with 0.1% formic acid (phase B). Results: The extract analysis identified the presence of ten compounds: two aryl propanoids (5-Ocaffeoylquinic acid and 3-O-feruloylquinic acid) and eight glycosylated flavones derived from apigenin, luteonin, and chrysoeryol (vicenin 2, saponarin, orientin, isoorientin, isoschaftoside, schaftoside, isovitexin, and isoscoparin). Conclusion: The developed UPLC-DAD method was proven to be an efficient tool for the separation of phenolic mixtures and the UPLC-DAD-MS analysis enabled the identification of these compounds, reported for the first time in Pourouma genus.

scholarly journals Preparative Capillary GC for Characterization of Five Dracocephalum Essential Oils from Mongolia, and their Mosquito Larvicidal Activity

2016 ◽  
Vol 11 (10) ◽  
pp. 1934578X1601101
Author(s):  
Gülmira Özek ◽  
Nurhayat Tabanca ◽  
Mohammed M. Radwan ◽  
Sanduin Shatar ◽  
Altaa Altantsetseg ◽  
...  
Keyword(s):  
Essential Oils ◽  
Larvicidal Activity ◽  
System Structure ◽  
Capillary Gc ◽  
Adulticidal Activity ◽  
Fraction Collector ◽  
First Time ◽  
C Nmr

The chemical composition and mosquito larvicidal and adulticidal activity of five essential oils (EOs), Dracocephalum ruyschiana L. (DR), D. foetidum Bunge (DF), D. moldavica L. (DM), D. fruticulosum Steph. ex Willd. (DFr) and D. peregrinum L. (DP) were evaluated. Simultaneous GC-FID and GC-MS analyses revealed in the EOs of DR, DF and DM an unidentified compound (1) ([M+122], 5.4%, 57.9% and 74.0%, respectively). Therefore, we aimed to isolate compound 1 using Preparative Capillary GC (PCGC) connected to a Preparative Fraction Collector (PFC) system. Structure determination of 1 was determined by 1H- and 13C-NMR as p-mentha-1,8-dien-10-al (1, limonen-10-al). Other detected major constituents were thymol (34.0%) and carvacrol (6.1%) in DR; limonene (28.8%) in DF; cis-chrysanthenol acetate (29.1%) and trans-verbenol (5.0%) in DFr; and linalool (17.9%), trans-β-bergamotene (7.9%), (E)-nerolidol (7.7%) and eugenol (5.5%) in DP. The DFr, DP, DR and DM EOs produced 100% mortality to 1st instar larvae of Aedes aegypti L. at 250 ppm and DR and DM EO exhibited the strongest activity and killed 100% 1st instar larvae at 62.5 ppm. No adulticidal activity was observed against female Ae. aegypti. In the scope of the present study, for the first time isolation of limonen-10-al (1) from DR, DM, and DP EOs and larvicidal activity of five Dracocephalum EOs were reported.

scholarly journals Fabrication of a Novel Electrochemical Sensor Based on Carbon Cloth Matrix Functionalized with MoO3 and 2D-MoS2 Layers for Riboflavin Determination

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1371
Author(s):  
Rayhane Zribi ◽  
Antonino Foti ◽  
Maria Grazia Donato ◽  
Pietro Giuseppe Gucciardi ◽  
Giovanni Neri
Keyword(s):  
Electrochemical Sensor ◽  
Limit Of Detection ◽  
Carbon Cloth ◽  
Electrochemical Characteristics ◽  
Mos2 Nanosheets ◽  
Fiber Network ◽  
Screen Printed Carbon Electrode ◽  
First Time

The preparation and characterization of a hybrid composite, based on carbon cloth (CC) matrix functionalized with two-dimensional (2D) MoS2 flakes and MoO3, and its use for developing an electrochemical sensor for the determination of riboflavin (RF) is here reported. The 2D-MoS2-MoO3CC composite was prepared by depositing 2D-MoS2 nanosheets, obtained by liquid phase exfoliation (LPE), on the surface of a carbon cloth fiber network, previously functionalized with a layer of molybdenum oxide (α-MoO3) by radio-frequency magnetron reactive sputtering technique. The 2D-MoS2-MoO3CC composite was characterized by scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX), and Raman spectroscopy. An electrochemical sensor has been then fabricated by fixing a slice of the 2D-MoS2-MoO3CC composite on the working electrode of a screen-printed carbon electrode (SPCE). The 2D-MoS2-MoO3-CC/SPCE sensor display good electrochemical characteristics which have been exploited, for the first time, in the electroanalytical determination of riboflavin (RF). The sensitivity to RF, equal to 0.67 µA mM−1 in the linear range from 2 to 40 µM, and a limit of detection (LOD) of 1.5 µM at S/N = 3, demonstrate the promising characteristics of the proposed 2D-MoS2-MoO3-CC/SPCE electrochemical sensor for the determination of riboflavin.

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