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201.
Dr. Peterson de Andrade Dr. Juan C. Muñoz-García Dr. Giulia Pergolizzi Valeria Gabrielli Dr. Sergey A. Nepogodiev Dr. Dinu Iuga László Fábián Rinat Nigmatullin Dr. Marcus A. Johns Dr. Robert Harniman Prof. Stephen J. Eichhorn Dr. Jesús Angulo Prof. Yaroslav Z. Khimyak Prof. Robert A. Field 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(4):1374-1382
Understanding the fine details of the self-assembly of building blocks into complex hierarchical structures represents a major challenge en route to the design and preparation of soft-matter materials with specific properties. Enzymatically synthesised cellodextrins are known to have limited water solubility beyond DP9, a point at which they self-assemble into particles resembling the antiparallel cellulose II crystalline packing. We have prepared and characterised a series of site-selectively fluorinated cellodextrins with different degrees of fluorination and substitution patterns by chemoenzymatic synthesis. Bearing in mind the potential disruption of the hydrogen-bond network of cellulose II, we have prepared and characterised a multiply 6-fluorinated cellodextrin. In addition, a series of single site-selectively fluorinated cellodextrins was synthesised to assess the structural impact upon the addition of one fluorine atom per chain. The structural characterisation of these materials at different length scales, combining advanced NMR spectroscopy and microscopy methods, showed that a 6-fluorinated donor substrate yielded multiply 6-fluorinated cellodextrin chains that assembled into particles presenting morphological and crystallinity features, and intermolecular interactions, that are unprecedented for cellulose-like materials. 相似文献
202.
203.
Cristian Peptu Oscar F. van den Brink Valeria Harabagiu Bogdan C. Simionescu Marek Kowalczuk Jerzy Silberring 《Journal of polymer science. Part A, Polymer chemistry》2012,50(12):2421-2431
End‐capped and intramolecular azofunctional oligocaprolactones were characterized at molecular level by liquid chromatography electrospray ionization mass spectrometry (ESI MS) and NMR spectroscopy. The Disperse Red 19 (DR19) azofunctional oligomers, DC, were synthesized by ring‐opening oligomerization of ε‐caprolactone (ε‐CL) initiated by the hydroxyl groups of DR19 azo dye. The reaction products consist of a minor fraction of end‐capped azo functional oligocaprolactone (α‐DC), that is, a single CL arm oligomer, and a major fraction of intramolecular azo functional oligocaprolactone (β‐DC), that is, a two CL arms oligomer. The chromatographic separation was used to discriminate between α‐DC and β‐DC, and the results were confirmed by MS/MS performed on an ESI ion trap instrument. The results supported by accurate mass data obtained for product ions using an ESI quadrupole time of flight instrument demonstrate the qualitative discrimination at the molecular level between intramolecular and end‐capped azofunctional oligoesters isomers through a relatively simple multistage mass spectrometry experiment. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
204.
Valeria Alzari Alberto Mariani Orietta Monticelli Luca Valentini Daniele Nuvoli Massimo Piccinini Sergio Scognamillo Silvia Bittolo Bon Javier Illescas 《Journal of polymer science. Part A, Polymer chemistry》2010,48(23):5375-5381
In this work, a new stimuli‐responsive composite polymer hydrogel containing partially exfoliated graphite was prepared by frontal polymerization. The materials obtained were characterized by differential scanning calorimetry, RAMAN, scan electron microscopy, transmission electron microscopy, atomic force microscopy, and in terms of swelling behavior. It was found that the maximum temperature reached by the polymerization front and the lower critical solution temperature are affected by the graphite content. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
205.
206.
207.
Dr. Sonia La Cognata Dr. Riccardo Mobili Prof. Chiara Milanese Dr. Massimo Boiocchi Dr. Mattia Gaboardi Prof. Donatella Armentano Dr. Johannes C. Jansen Dr. Marcello Monteleone Dr. Ariana R. Antonangelo Dr. Mariolino Carta Prof. Valeria Amendola 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(49):e202201631
Two novel imide/imine-based organic cages have been prepared and studied as materials for the selective separation of CO2 from N2 and CH4 under vacuum swing adsorption conditions. Gas adsorption on the new compounds showed selectivity for CO2 over N2 and CH4. The cages were also tested as fillers in mixed-matrix membranes for gas separation. Dense and robust membranes were obtained by loading the cages in either Matrimid® or PEEK-WC polymers. Improved gas-transport properties and selectivity for CO2 were achieved compared to the neat polymer membranes. 相似文献
208.
Richard Marins da Silva Valeria Monteze Guimarães Lizzy Ayra Alcântara Veríssimo Márcia Cristina Teixeira Ribeiro Vidigal Valéria Paula Rodrigues Minim Luis Antonio Minim 《Journal of separation science》2022,45(2):401-410
This study focused on the extraction, purification, and physicochemical characterization of γ-conglutin, a protein present in lupin seeds with properties of reducing blood glucose levels. Total protein was extracted with an alkaline-saline solvent, followed by isoelectric precipitation. Chromatographic purification of the precipitated fraction was performed using a cation exchange supermacroporous cryogel column. Electrophoresis of the eluted fraction from chromatography presented a single band of ∼48 kDa under non-reducing conditions (two bands of ∼30 and ∼17 kDa, under reducing conditions) confirming the success of the purification protocol. Liquid chromatography-tandem mass spectrometry analysis confirmed the identity of the protein as γ-conglutin. The purified γ-conglutin had an isoelectric point of 7.51, β-sheets prevailing as a secondary structure, and denaturation temperature close to 68°C. The outcome of this work showed that γ-conglutin was obtained with a high degree of purity. The proposed purification protocol is simple and can be easily scaled up. 相似文献
209.
Angela Chambery Antimo Di Maro Carmen Sanges Valeria Severino Maura Tarantino Annalisa Lamberti Augusto Parente Paolo Arcari 《Analytical and bioanalytical chemistry》2009,395(7):2281-2291
Diagnostic techniques applied to the field of cultural heritage represent a very important aspect of scientific investigation.
Recently, proteomic approaches based on mass spectrometry coupled with traditional spectroscopic methods have been used for
painting analysis, generating promising results for binder’s protein identification. In the present work, an improved procedure
based on LC-ESI/Q-q-TOF tandem mass spectrometry for the identification of protein binders has been developed for the molecular
characterization of samples from an early-twentieth-century mural painting from the St. Dimitar Cathedral in Vidin, Bulgaria.
The proteomic investigation has led to the identification of both egg white and egg yolk proteins, according to traditional
old recipes for tempera paintings. In addition, beyond the egg components, the presence of caseins was also revealed, thus
suggesting the use of milk as binding medium, fixative or stabilising agent. Furthermore, for the first time, the capability
to discriminate the milk origin on the basis of alpha casein proteotypic peptides is reported, that are diagnostic for a given
species, thus opening interesting perspectives in art and archaeological fields. 相似文献
210.
Paula V. Messina Valeria Verdinelli Pablo C. Schulz 《Colloid and polymer science》2006,285(3):251-261
The properties of a scarcely studied twin-tailed surfactant, sodium dioctylphosphinate (SDOP), as emulsifier were studied. The SDOP hidrophile–lipophile balance (HLB) value was measured and the Davies HLB group number of the sodium phosphinate group was computed. The surfactant promotes the formation of water in petroleum ether emulsions. The emulsion was characterized by the employment of several techniques such as centrifuge test and turbidimetry and density measurements. The maximum stability was obtained by the surfactant concentration of 0.3 mol dm−3 with 14 g of water emulsified in 12.41 g oil/g surfactant was emulsified. Conductivity information was used to study the temperature effect on the emulsion droplets and the energy of the droplet clustering during percolation. The enthalpy of adsorption at the oil/water interface was positive at all surfactant concentrations ([S]); its absolute value showed a maximum of [S]=0.1 mol dm−3 and subsequent decreased was attributed to a change in the droplet interface, which would provide the necessary energy for the adsorption of SDOP molecules. The determination of droplet clustering thermodynamic parameters during percolation showed that droplet clusters were formed spontaneously and the process driving force was a negative enthalpy contribution. 相似文献