The impact of chemical structure and molecular packing on the electronic polarisation of fullerene arrays

2017 ◽  
Vol 19 (28) ◽  
pp. 18709-18720 ◽  
Author(s):  
Sheridan Few ◽  
Cleaven Chia ◽  
Daniel Teo ◽  
James Kirkpatrick ◽  
Jenny Nelson
Keyword(s):  
Charge Separation ◽  
Chemical Structure ◽  
Molecular Packing ◽  
Large Influence ◽  
The Impact

Calculations show that molecular packing motif and direction of separation have a large influence on the energetic landscape for charge separation in fullerene arrays.

scholarly journals Influence of the Anthocyanin and Cofactor Structure on the Formation Efficiency of Naturally Derived Pyranoanthocyanins

2021 ◽  
Vol 22 (13) ◽  
pp. 6708
Author(s):  
Gonzalo Miyagusuku-Cruzado ◽  
Danielle M. Voss ◽  
M. Monica Giusti
Keyword(s):  
Caffeic Acid ◽  
Chemical Structure ◽  
Sinapic Acid ◽  
Molar Ratio ◽  
Tandem Mass ◽  
Limited Information ◽  
Formation Efficiency ◽  
The Impact ◽  
And Storage ◽  
H 20

Pyranoanthocyanins are anthocyanin-derived pigments with higher stability to pH and storage. However, their slow formation and scarcity in nature hinder their industrial application. Pyranoanthocyanin formation can be accelerated by selecting anthocyanin substitutions, cofactor concentrations, and temperature. Limited information is available on the impacts of the chemical structure of the cofactor and anthocyanin; therefore, we evaluated their impacts on pyranoanthocyanin formation efficiency under conditions reported as favorable for the reaction. Different cofactors were evaluated including pyruvic acid, acetone, and hydroxycinnamic acids (p-coumaric, caffeic, ferulic, and sinapic acid) by incubating them with anthocyanins in a molar ratio of 1:30 (anthocyanin:cofactor), pH 3.1, and 45 °C. The impact of the anthocyanin aglycone was evaluated by incubating delphinidin, cyanidin, petunidin, or malvidin derivatives with the most efficient cofactor (caffeic acid) under identical conditions. Pigments were identified using UHPLC-PDA and tandem mass spectrometry, and pyranoanthocyanin formation was monitored for up to 72 h. Pyranoanthocyanin yields were the highest with caffeic acid (~17% at 72 h, p < 0.05). When comparing anthocyanins, malvidin-3-O-glycosides yielded twice as many pyranoanthocyanins after 24 h (~20%, p < 0.01) as cyanidin-3-O-glycosides. Petunidin- and delphinidin-3-O-glycosides yielded <2% pyranoanthocyanins. This study demonstrated the importance of anthocyanin and cofactor selection in pyranoanthocyanin production.

scholarly journals Impact of Nanoparticle Consolidation on Charge Separation Efficiency in Anatase TiO2 Films

2021 ◽  
Vol 9 ◽  
Author(s):  
Karin Rettenmaier ◽  
Thomas Berger
Keyword(s):  
Thermal Annealing ◽  
Charge Separation ◽  
Separation Efficiency ◽  
Internal Surface ◽  
Processing Temperature ◽  
Cyclic Voltammograms ◽  
Internal Surface Area ◽  
Deep Traps ◽  
Charge Separation Efficiency ◽  
The Impact

Mesoporous films and electrodes were prepared from aqueous slurries of isolated anatase TiO2 nanoparticles. The resulting layers were annealed in air at temperatures 100°C ≤ T ≤ 450°C upon preservation of internal surface area, crystallite size and particle size. The impact of processing temperature on charge separation efficiency in nanoparticle electrodes was tracked via photocurrent measurements in the presence of methanol as a hole acceptor. Thermal annealing leads to an increase of the saturated photocurrent and thus of the charge separation efficiency at positive potentials. Furthermore, a shift of capacitive peaks in the cyclic voltammograms of the nanoparticle electrodes points to the modification of the energy of deep traps. Population of these traps triggers recombination possibly due to the action of local electrostatic fields attracting photogenerated holes. Consequently, photocurrents saturate at potentials, at which deep traps are mostly depopulated. Charge separation efficiency was furthermore investigated for nanoparticle films and was tracked via the decomposition of hydrogen peroxide. Our observations evidence an increase of charge separation efficiency upon thermal annealing. The effect of particle consolidation, which we associate with minute atomic rearrangements at particle/particle contacts, is attributed to the energetic modification of deep traps and corresponding modifications of charge transport and recombination, respectively.

scholarly journals The application of a phosphorus nitrogen flame retardant curing agent in epoxy resin

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 545-554 ◽  
Author(s):  
Anxin Li ◽  
Pingli Mao ◽  
Bing Liang
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Adhesive Strength ◽  
Chemical Structure ◽  
Phosphorus Content ◽  
Raw Material ◽  
Curing Agent ◽  
Thermal Degradation Behavior ◽  
Overall Performance ◽  
The Impact

AbstractIn order to improve the compatibility of flame retardant and epoxy resin, a phosphorus nitrogen flame retardant curing agent poly(p-xylylenediamine spirocyclic pentaerythritol bisphosphonate) (PPXSPB) was synthesized. FTIR, 1HNMR, and mass spectroscopy were used to identify the chemical structure of PPXSPB. Epoxy resin (E-44) and PPXSPB as the raw material, a series of thermosetting systems were prepared. The effects of PPXSPB on flame retardancy, water resistance, thermal degradation behavior, mechanical properties and the adhesive strength of EP/PPXSPB thermosets were investigated. The results show that with the increase of phosphorus content, the oxygen index and carbon residue of the system both increased significantly, and the heat release rate gradually decreased, which is of great significance in delaying the occurrence of fire. When the phosphorus content is 3.24% in EP/PPXSPB thermosets, EP-2 can successfully pass the UL94 V-0 flammability rating, the LOI value of EP-2 can reach 31.4%, the impact strength and tensile strength was 6.58 kJ/m2 and 47.10 MPa respectively, and the adhesive strength was 13.79 MPa, the system presents a good overall performance.

scholarly journals Bio-Based Packaging Materials Containing Substances Derived from Coffee and Tea Plants

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5719
Author(s):  
Olga Olejnik ◽  
Anna Masek
Keyword(s):  
Mechanical Properties ◽  
Caffeic Acid ◽  
Green Tea ◽  
Chemical Structure ◽  
Green Tea Extract ◽  
Packaging Materials ◽  
Scanning Calorimetry ◽  
Spectra Analysis ◽  
Tea Extract ◽  
The Impact

The aim of the research was to obtain intelligent and eco-friendly packaging materials by incorporating innovative additives of plant origin. For this purpose, natural substances, including green tea extract (polyphenon 60) and caffeic acid, were added to two types of biodegradable thermoplastics (Ingeo™ Biopolymer PLA 4043D and Bioplast GS 2189). The main techniques used to assess the impact of phytocompounds on materials’ thermal properties were differential scanning calorimetry (DSC) and thermogravimetry (TGA), which confirmed the improved resistance to thermo-oxidation. Moreover, in order to assess the activity of applied antioxidants, the samples were aged using a UV aging chamber and a weathering device, then retested in terms of dynamic mechanical properties (DMA), colour changing, Vicat softening temperature, and chemical structure, as studied using FT-IR spectra analysis. The results revealed that different types of aging did not cause significant differences in thermo-mechanical properties and chemical structure of the samples with natural antioxidants but induced colour changing. The obtained results indicate that polylactide (PLA) and Bioplast GS 2189, the plasticizer free thermoplastic biomaterial containing polylactide and starch (referred to as sPLA in the present article), both with added caffeic acid and green tea extract, can be applied as smart and eco-friendly packaging materials. The composites reveal better thermo-oxidative stability with reference to pure materials and are able to change colour as a result of the oxidation process, especially after UV exposure, providing information about the degree of material degradation.

Impact of molecular packing rearrangement on solid-state fluorescence: polyhalogenated N-hetarylamines vs. their co-crystals with 18-crown-6

CrystEngComm ◽  
2019 ◽  
Vol 21 (39) ◽  
pp. 5931-5946 ◽  
Author(s):  
Tamara A. Vaganova ◽  
Yurij V. Gatilov ◽  
Enrico Benassi ◽  
Igor P. Chuikov ◽  
Denis P. Pishchur ◽  
...  
Keyword(s):  
Solid State ◽  
Chemical Structure ◽  
Crystal Packing ◽  
Molecular Packing ◽  
Solid State Fluorescence

Relationship between the hetarylamine chemical structure, crystal packing in homo- and co-crystals, and fluorescence effects (quenching, bathochromic and hypsochromic shifts).

The impact of chemical structure on polyphenol bioaccessibility, as a function of processing, cell wall material and pH: A model system

2021 ◽  
Vol 289 ◽  
pp. 110304 ◽  
Author(s):  
Eden Eran Nagar ◽  
Liora Berenshtein ◽  
Inbal Hanuka Katz ◽  
Uri Lesmes ◽  
Zoya Okun ◽  
...  
Keyword(s):  
Cell Wall ◽  
Chemical Structure ◽  
Model System ◽  
Wall Material ◽  
Cell Wall Material ◽  
The Impact

scholarly journals Asteroseismology of ZZ Ceti stars with full evolutionary white dwarf models

2018 ◽  
Vol 613 ◽  
pp. A46 ◽  
Author(s):  
F. C. De Gerónimo ◽  
L. G. Althaus ◽  
A. H. Córsico ◽  
A. D. Romero ◽  
S. O. Kepler
Keyword(s):  
White Dwarf ◽  
Chemical Structure ◽  
Asymptotic Giant Branch ◽  
Evolutionary Computations ◽  
Instability Strip ◽  
Average Deviation ◽  
Intermediate Mass Stars ◽  
Nuclear Burning ◽  
The Impact ◽  
Thermal Pulses

Context. The thermally pulsing phase on the asymptotic giant branch (TP-AGB) is the last nuclear burning phase experienced by most low- and intermediate-mass stars. During this phase, the outer chemical stratification above the C/O core of the emerging white dwarf (WD) is built up. The chemical structure resulting from progenitor evolution strongly impacts the whole pulsation spectrum exhibited by ZZ Ceti stars, which are pulsating C/O core white dwarfs located on a narrow instability strip at Teff ~ 12 000 K. Several physical processes occurring during progenitor evolution strongly affect the chemical structure of these stars; those found during the TP-AGB phase are the most relevant for the pulsational properties of ZZ Ceti stars. Aims. We present a study of the impact of the chemical structure built up during the TP-AGB evolution on the stellar parameters inferred from asteroseismological fits of ZZ Ceti stars. Methods. Our analysis is based on a set of carbon–oxygen core white dwarf models with masses from 0.534 to 0.6463 M⊙ derived from full evolutionary computations from the ZAMS to the ZZ Ceti domain. We computed evolutionary sequences that experience different number of thermal pulses (TP). Results. We find that the occurrence or not of thermal pulses during AGB evolution implies an average deviation in the asteroseimological effective temperature of ZZ Ceti stars of at most 8% and on the order of ≲5% in the stellar mass. For the mass of the hydrogen envelope, however, we find deviations up to 2 orders of magnitude in the case of cool ZZ Ceti stars. Hot and intermediate temperature ZZ Ceti stars show no differences in the hydrogen envelope mass in most cases. Conclusions. Our results show that, in general, the impact of the occurrence or not of thermal pulses in the progenitor stars is not negligible and must be taken into account in asteroseismological studies of ZZ Ceti stars.

N- and P-Type Building Blocks for Organic Electronics Based on Oligothiophene Cores

2003 ◽  
Vol 771 ◽  
Author(s):  
Antonio Facchetti ◽  
Myung-Han Yoon ◽  
Howard E. Katz ◽  
Melissa Mushrush ◽  
Tobin J. Marks
Keyword(s):  
Organic Semiconductors ◽  
Organic Electronics ◽  
Carrier Mobility ◽  
Building Blocks ◽  
Molecular Packing ◽  
Conjugation Length ◽  
Π Interactions ◽  
P Type ◽  
The Impact ◽  
Homo Lumo

AbstractOrganic semiconductors exhibiting complementary-type carrier mobility are the key components for the development of the field of “gplastic electronics” We present here a novel series of α,ω- and isomerically pure ββ'-diperfluorohexyl-substituted thiophene and study the impact of fluoroalkyl substitution and conjugation length vis-a-vis the corresponding fluorinefree analogues. Trends between the fluorinated and fluorine-free families in molecular packing, HOMO-LUMO gap, and π-π interactions are found to be strikingly similar. TFT measurements indicate that all members of the fluorinated series are n-type semiconductors

Elucidating the Impact of Molecular Packing and Device Architecture on the Performance of Nanostructured Perylene Diimide Solar Cells

2015 ◽  
Vol 7 (16) ◽  
pp. 8687-8698 ◽  
Author(s):  
Eduardo Aluicio-Sarduy ◽  
Ranbir Singh ◽  
Zhipeng Kan ◽  
Tengling Ye ◽  
Aliaksandr Baidak ◽  
...  
Keyword(s):  
Solar Cells ◽  
Molecular Packing ◽  
Perylene Diimide ◽  
Device Architecture ◽  
The Impact
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