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51.
52.
Arto Valkonen Katri Laihia Erkki Kolehmainen Reijo Kauppinen Pál Perjési 《Structural chemistry》2012,23(1):209-217
1H and 13C NMR chemical shifts have been determined and assigned based on PFG 1H, 13C HMQC, and HMBC experiments for 3-(4′-X-benzyl)-4-chromenones (Ia, X = CN and Ib, X = NO2), 3-(4′-X-benzyl)-4-thiochromenones (IIa, X = Cl and IIb, X = Br), (E)-3-(4′-X-benzylidene)-4-chromanones (IIIa–IIIe, X = OCH3, CH3, Cl, N(CH3)2, Br), (Z)-3-(4′-X-benzylidene)4-thiochromanones (IVa–IVd, X = Cl, Br, F, OCH3), 2-benzyl-1,2,3,4-tetrahydro-1-naphthol (V), 2-benzyl- and (E)-2-benzylidene-1-tetralones (VI and VII), and (E)-2-benzylidene-1-benzosuberol (VIII). The crystal structures have been determined for the following seven compounds: derivatives of 4-chromanones (IIIa–IIId), 1-tetrahydronaphtol (V), and 1-tetralones (VI and VII). The molecular features and intermolecular interactions in crystal state have been discussed. 相似文献
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54.
Jukka Niskanen Jun Shan Heikki Tenhu Hua Jiang Esko Kauppinen Violeta Barranco Fernando Picó Kirsi Yliniemi Kyösti Kontturi 《Colloid and polymer science》2010,288(5):543-553
Silver ions being less toxic than silver nanoparticles, a more safe material can be obtained to be used as antimicrobial coating.
This can be achieved by using thiol chemistry and covalently attach the silver nanoparticles in the coating. Our aim is to
produce a coating having antimicrobial properties of silver ions but with the silver nanoparticles firmly attached in the
coating. Here, we present a way to produce silver nanoparticles that can be used as a component in a coating or as such to
produce an antimicrobial coating. The silver nanoparticles presented here are stabilized by a copolymer (poly(butyl acrylate–methyl
methacrylate)) that is soft and has well-known good film-producing properties. The reversible addition-fragmentation chain
transfer radical polymerization technique used to prepare the polymers provides conveniently a thiol group for effective binding
of the silver nanoparticles to the polymers and thus to the coating. 相似文献
55.
Petri Kanninen Virginia Ruiz Tanja Kallio I.V. Anoshkin Esko I. Kauppinen Kyösti Kontturi 《Electrochemistry communications》2010,12(9):1257-1260
Pyrroloquinoline quinone (PQQ) was immobilized on glassy-carbon electrodes (GCE) modified with single-walled carbon nanotubes (SWCNT), few-walled carbon nanotubes (FWCNT) and carbon black (Vulcan XC72R). Modified electrodes were prepared by drop-casting. Immobilization was achieved with an extremely simple dipping procedure and without any further modification to the electrodes. Electrochemical performance of the electrodes was studied by cyclic voltammetry and spectroelectrochemistry. FWCNT adsorbed 30 times more PQQ than the other carbon materials. Compared to more complicated immobilization methods, PQQ/FWCNT/GCE showed well-defined electrochemistry in a considerably wide pH area from 2 to 12. The dipping process is affected by pH and electrostatic forces. At dipping pH 9.5, where both FWCNTs and PQQ have strong negative charge, the adsorption was halved compared to dipping pH 2, where the charges are smaller. 相似文献
56.
Ośmiałowski B Kolehmainen E Gawinecki R Dobosz R Kauppinen R 《The journal of physical chemistry. A》2010,114(49):12881-12887
Intermolecular hydrogen bonds between 2,6-bis(acylamino)pyridines and dipyridin-2-ylamine as well as 4,4-dimethylpiperidine-2,6-dione are responsible for relatively strong interactions between these species. Association has been found to be significantly affected by the size of acyl substituent (chemical shift of the NH proton was used as the main probe in determination of the association constants). Calculations at the DFT level of theory are in line with the experimentally observed results. Calculated energies of the interactions between the complex congeners also show the size of the substituent to affect the association. Conformational changes in the dipyridin-2-ylamine molecule are shown to adapt a geometry suitable for formation of efficient hydrogen bonding. 相似文献
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58.
Ville Saarimaa Jere Manni Esko Kauppinen Antti Markkula Jyrki Juhanoja Bengt‐Johan Skrifvars 《Surface and interface analysis : SIA》2014,46(9):620-624
Hexavalent chromium containing pretreatments and primers for coil coating are soon to be entirely prohibited, which sets new demands for Cr‐free alternatives. Most of the presently used Cr‐free pretreatment layers operate predominantly via barrier formation and adhesion promotion mechanisms and lack the self‐healing effect typical for Cr6+‐pretreatments. This sets new demands also for the formation and monitoring of these layers. The barrier thickness and chemical composition of Cr‐free pretreatment layers on hot dip galvanized steel were studied using cross sections from broad ion beam (BIB) sample preparation and ultramicrotome cutting. BIB milling provided finely polished cross sections of pretreated samples. Film thicknesses of 20–50 nm were accurately determined for Cr‐free pretreatments containing 4–10 mg Ti/m2 using BIB milling and scanning electron microscopy imaging. Scanning transmission electron microscopy, integrated with aberration correctors and X‐ray energy dispersive spectrometry, of an ultramicrotome cut pretreated and painted samples provided detailed chemical information. Metal complexes were detected close to the pretreatment/zinc interface, while the polymeric part of the pretreatment layer prevailed closer to paint. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
59.
Coronene Encapsulation in Single‐Walled Carbon Nanotubes: Stacked Columns,Peapods, and Nanoribbons 下载免费PDF全文
Dr. Ilya V. Anoshkin Dr. Alexandr V. Talyzin Prof. Albert G. Nasibulin Dr. Arkady V. Krasheninnikov Hua Jiang Prof. Risto M. Nieminen Prof. Esko I. Kauppinen 《Chemphyschem》2014,15(8):1660-1665
Encapsulation of coronene inside single‐walled carbon nanotubes (SWNTs) was studied under various conditions. Under high vacuum, two main types of molecular encapsulation were observed by using transmission electron microscopy: coronene dimers and molecular stacking columns perpendicular or tilted (45–60°) with regard to the axis of the SWNTs. A relatively small number of short nanoribbons or polymerized coronene molecular chains were observed. However, experiments performed under an argon atmosphere (0.17 MPa) revealed reactions between the coronene molecules and the formation of hydrogen‐terminated graphene nanoribbons. It was also observed that the morphology of the encapsulated products depend on the diameter of the SWNTs. The experimental results are explained by using density functional theory calculations through the energies of the coronene molecules inside the SWNTs, which depend on the orientation of the molecules and the diameter of the tubes. 相似文献
60.
Numerous organic and inorganic laboratory standards were gathered from nine European and North American laboratories and were analyzed for their delta(18)O values with a new on-line high temperature pyrolysis system that was calibrated using Vienna standard mean ocean water (VSMOW) and standard light Antartic precipitation (SLAP) internationally distributed reference water samples. Especially for organic materials, discrepancies between reported and measured values were high, ranging up to 2 per thousand. The reasons for these discrepancies are discussed and the need for an exact and reliable calibration of existing reference materials, as well as for the establishment of additional organic and inorganic reference materials is stressed. Copyright 1999 John Wiley & Sons, Ltd. 相似文献