@article {CAO2022100680, title = {Adsorption behavior of anthraquinones in deep eutectic solvent on polyester fiber and its application}, journal = {Sustainable Chemistry and Pharmacy}, volume = {27}, year = {2022}, pages = {100680}, abstract = {

Deep eutectic solvents (DESs can be used to facilitate the adsorption of anthraquinone dyes into polyester fabrics (PETFs) in facile conditions. The adsorption mechanism was investigated through a systematic characterisation study using methods including 1H nuclear magnetic resonance spectroscopy, ultraviolet\–visible spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, water contact angle analysis, and tensile strength tests. It was found that anthraquinone dyes have different types of interactions with DESs, and that the adsorption and dyeing of PETF can be achieved only when the interactions between PETF and anthraquinones were stronger than those between the PETF and DESs. Additionally, the type of DES, hydrogen bond acceptor\–hydrogen bond donor ratio, dye concentration, dyeing temperature, and dyeing time affect the adsorption and dyeing efficiency. In summary, PETF was successfully dyed with DES as a solvent, and the presence of DES did not destroy the PETF or significantly change its properties. Meanwhile, anthraquinone dyes affect the properties of PETF by forming non-covalent interactions. This study provides insights into problems encountered with adsorption and separation of target compounds in DESs, and provides the textile industry with a potentially much greener alternative that can reduce energy consumption and pollutant emissions, and avoid using toxic solvents for dyeing fabrics using DESs.

}, keywords = {ADSORPTION, Deep eutectic solvent, Dispersive dye, Polyester fabric}, issn = {2352-5541}, doi = {https://doi.org/10.1016/j.scp.2022.100680}, url = {https://www.sciencedirect.com/science/article/pii/S2352554122000845}, author = {Dan Cao and Min Liu and Yung-Chih Su and Zehui Yang and Wentao Bi and David D. Y. Chen} } @article {2673, title = {Structures of Water Molecules at the Interfaces of Aqueous Salt Solutions and Silica: Cation Effects}, journal = {Journal of Physical Chemistry C}, volume = {113}, number = {19}, year = {2009}, note = {ISI Document Delivery No.: 443FLTimes Cited: 6Cited Reference Count: 53Yang, Zheng Li, Qifeng Chou, Keng C.}, month = {May}, pages = {8201-8205}, type = {Article}, abstract = {Structures of water molecules at water/silica interfaces, in the presence of alkali chloride. were investigated using infrared-visible sum frequency vibrational spectroscopy. Significant perturbations of the interfacial water structure were observed on silica surfaces with the NaCl concentration as low as 1 x 10(-4) M. The cations, which interact with the Silica Surface via electrostatic interaction, play key roles in Perturbing the hydrogen-bond network of water molecules at the water/silica interface. This cation effect becomes saturated at concentrations around 10(-2) to 10(-1) M, where the sum frequency generation peaks at 3200 and 3400 cm(-1) decrease by 75\%. Different alkali cation species (Li+, Na+, and K+) produce different magnitudes of perturbation, with K+ > Li+ > Na+. This order can be explained by considering the effective ionic radii of the hydrated cations and the electrostatic interactions between the hydrated cations and silica Surfaces. The interfacial water structure associated with the 3200 cm(-1) band is more vulnerable to the cation perturbation, Suggesting that the more ordered water structure on silica is likely associated with the vincinal silanol groups, which create a higher local surface electrical field on silica.}, keywords = {ADSORPTION, charge, DYNAMICS SIMULATIONS, ELECTROLYTE INTERFACE, hydration, INTERFACE, LIQUID WATER, SOLID/LIQUID, SUM-FREQUENCY SPECTROSCOPY, SURFACE, vibrational spectroscopy}, isbn = {1932-7447}, url = {://000265895500034}, author = {Yang, Z. and Li, Q. F. and Chou, K. C.} } @article {1225, title = {Entropic interaction chromatography: Separating proteins on the basis of size using end-grafted polymer brushes}, journal = {Biotechnology and Bioengineering}, volume = {90}, number = {1}, year = {2005}, note = {ISI Document Delivery No.: 909ETTimes Cited: 9Cited Reference Count: 48}, month = {Apr}, pages = {1-13}, type = {Article}, abstract = {Partitioning of a macromolecule into the interfacial volume occupied by a grafted polymer brush decreases the configurational entropy (Delta S(c)brush) of the terminally attached linear polymer chains due to a loss of free volume. Self-consistent field theory (SCF) calculations are used to show that Delta S(c)brush is a strong function of both the size (MW,) of the partitioning macromolecule and the depth of penetration into the brush volume. We further demonstrate that the strong dependence of Delta S(c)brush on MW, provides a novel and powerful platform, which we call entropic interaction chromatography (EIC), for efficiently separating mixtures of proteins on the basis of size. Two EIC columns, differing primarily in polymer grafting density, were prepared by growing a brush of poly(methoxyethyl acrylamide) chains on the surface of a widepore (1,000-angstrom pores, 64-mu m diameter rigid beads) resin (Toyopearl AF-650M) bearing surface aldehyde groups. Semipreparative 0.1-L columns packed with either EIC resin provide reduced-plate heights of 2 or less for efficient separation of globular protein mixtures over at least three molecular-weight decades. Protein partitioning within these wide-pore EIC columns is shown to be effectively modeled as a thermodynamically controlled process, allowing partition coefficients (K-p) and elution chromatograms to be accurately predicted using a column model that combines SCF calculation of Kp values with an equilibrium-dispersion type model of solute transport through the column. This model is used to explore the dependence of column separation efficiency on brush properties, predicting that optimal separation of proteins over a broad MW, range is achieved at low to moderate grafting densities and intermediate chain lengths. (c) 2005 Wiley Periodicals, Inc.}, keywords = {ADSORPTION, CHAIN MOLECULES, CONSISTENT-FIELD THEORY, entropic interaction chromatography, equilibrium dispersion, EXCLUSION CHROMATOGRAPHY, GEL FILTRATION, grafted polymer brush, HUMAN SERUM-ALBUMIN, LIQUID-CHROMATOGRAPHY, MODEL, MOLECULAR-WEIGHT, MONTE-CARLO, protein purification, size exclusion chromatography, STATISTICAL-THEORY}, isbn = {0006-3592}, url = {://000227843800001}, author = {Pang, P. and Koska, J. and Coad, B. R. and Brooks, D. E. and Haynes, C. A.} } @article {866, title = {Molecular weight and polydispersity estimation of adsorbing polymer brushes by atomic force microscopy}, journal = {Langmuir}, volume = {20}, number = {8}, year = {2004}, note = {ISI Document Delivery No.: 811CPTimes Cited: 23Cited Reference Count: 36}, month = {Apr}, pages = {3297-3303}, type = {Article}, abstract = {{We have estimated the molecular weight, M-n, and polydispersity, PDI, of densely grafted poly(N-isopropylacrylamide) (PNIPAM) brushes using a novel atomic force microscopy (AFM) approach. When compression of a polymer brush induced adsorption of multiple chains to an AFM tip, the resulting decompression force profile exhibited a maximum attractive force at a separation, L-m, that decayed to zero with increasing tip-sample separation. We have found that the separation L approximates the average contour length, L,, determined by gel permeation chromatography (GPC). The detection of a decaying attractive force at separations larger than L, suggests that chains of above average length sequentially break free from the tip as they are stretched away from the grafting surface. The shape of the decompression profile in this region approximately paralleled the cumulative weight fraction of the grafted chains determined by GPC. The fraction of chains of a given molecular weight determined from a single force curve fit a log-normal distribution, having a standard deviation that provided an estimate of the PDL We have characterized two PNIPAM brushes by this AFM technique as well as by GPC coupled to a multiangle laser light-scattering detector (MALLS). The values obtained by AFM-(1) Mn,(AFM) = (3.8 +/- 0.5) X 104}, keywords = {ADSORPTION, AFM, CHAIN ELONGATION, ELASTIC PROPERTIES, PHASE, POLY(ACRYLAMIDE), POLY(N-ISOPROPYLACRYLAMIDE), SPECTROSCOPY, SURFACES}, isbn = {0743-7463}, url = {://000220750300044}, author = {Goodman, D. and Kizhakkedathu, J. N. and Brooks, D. E.} } @article {894, title = {Plasma protein adsorption to surfaces grafted with dense homopolymer and copolymer brushes containing poly(N-isopropylacrylamide)}, journal = {Journal of Biomaterials Science-Polymer Edition}, volume = {15}, number = {9}, year = {2004}, note = {ISI Document Delivery No.: 865ALTimes Cited: 13Cited Reference Count: 38Symposium on Gels, Genes, Grafts and Giants held in Celebration of the 70th Birthday of Allan HoffmanDEC, 2002Maui, HIUniv Washington Engineered Biomat NSF Engn Res Ctr}, pages = {1121-1135}, type = {Proceedings Paper}, abstract = {Growing polymer chains from surface initiators in principle allows much more dense polymer surface layers to be created than can be produced by grafting of whole (self-excluding) chains. We have utilized aqueous atom transfer radical polymerization to graft a series of cleavable hydrophilic poly (N-isopropylacrylamide) (PNIPAM) homopolymers and block copolymers of substituted acry-lamides from polystyrene latex to give brushes of controlled MW and surface density. Average chain separations much less than their free solution radii of gyration have been achieved. Exposure to radiolabeled single proteins or to whole plasma and subsequent analysis by SDS-PAGE shows that PNIPAM brushes decrease protein adsorption relative to the latex surface or other substituted polyacrylamides. The PNIPAM brushes exhibit a second-order phase transition around 30degreesC as reflected by a decrease in the hydrodynamic thickness of the brush at higher temperatures. Total plasma protein adsorption is increased at 40degreesC compared to 20degreesC but there is significant differential adsorption behavior among the proteins detected by gel-electrophoresis analysis.}, keywords = {ADSORPTION, BIOMATERIALS, block copolymer, CHROMATOGRAPHY, FIBRINOGEN ADSORPTION, grafted latex, I-125 radiolabel, MODEL, OXIDE), plasma protein, POLY(ETHYLENE GLYCOL), POLY(N-ISOPROPYLACRYLAMIDE), polymer brush, POLYMER BRUSHES, PREVENTION, SDS-PAGE, SELF-ASSEMBLED MONOLAYERS, SERUM-ALBUMIN ADSORPTION}, isbn = {0920-5063}, url = {://000224674600005}, author = {Janzen, J. and Le, Y. and Kizhakkedathu, J. N. and Brooks, D. E.} } @article {653, title = {Synthesis of poly(N,N-dimethylacrylamide) brushes from charged polymeric surfaces by aqueous ATRP: Effect of surface initiator concentration}, journal = {Macromolecules}, volume = {36}, number = {3}, year = {2003}, note = {ISI Document Delivery No.: 643NUTimes Cited: 49Cited Reference Count: 34}, month = {Feb}, pages = {591-598}, type = {Article}, abstract = {We have synthesized polystyrene shell latex (PSL) surfaces with different initiator concentrations by changing the feed ratio of styrene to 2-(methyl-2{\textquoteright}-chloropropionato)ethyl acrylate (HEACl) in a series of shell-growth copolymerization reactions. Surfaces were characterized by conductometric titration of saponified and nonsaponified functionalized PSL to give the surface charge and initiator concentrations accessible to aqueous reagents and by H-1 NMR methods. Poly(N,N-dimethylacrylamide) brushes were grafted from the functionalized surfaces by aqueous atom transfer radical polymerization and the dependence of molecular weight and chain density determined as a function of monomer concentration, ligand type, and surface initiator concentration by analyzing the chains cleaved from the PSL by saponification. M. varies linearly with monomer concentration for most systems, and grafting density is roughly independent of monomer concentration except at the highest initiator concentration. Very high molecular weights were obtained at low initiator concentration, up to M-n similar to 1.2 x 10(6) with M-w/M-n < 1.3; chain separations down to 1.1 mn and brush thicknesses to similar to800 nm were found. Grafting density varies as (initiator surface concentration)(2.6). The surface charge density also varies among the latexes synthesized and seems to play a role in this strong dependence on surface initiator concentration, perhaps by partially immobilizing the positively charged catalyst complex.}, keywords = {ADSORPTION, SELF-ASSEMBLED MONOLAYERS, SUBSTRATE, TRANSFER RADICAL POLYMERIZATION}, isbn = {0024-9297}, url = {://000180868000015}, author = {Kizhakkedathu, J. N. and Brooks, D. E.} } @inbook {654, title = {Synthesis of poly(N,N-dimethylacrylamide) brushes from functionalized latex surfaces by aqueous atom transfer radical polymerization}, booktitle = {Advances in Controlled/Living Radical Polymerization}, series = {Acs Symposium Series}, volume = {854}, year = {2003}, note = {ISI Document Delivery No.: BW85KTimes Cited: 7Cited Reference Count: 30Proceedings Paper224th National Meeting of the American-Chemical-SocietyAUG 17-22, 2002BOSTON, MASSACHUSETTSAmer Chem Soc1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 USA}, pages = {316-330}, publisher = {Amer Chemical Soc}, organization = {Amer Chemical Soc}, address = {Washington}, abstract = {Negatively charged, ATRP initiator functionalized polystyrene latexes were synthesized and N,N-dimethylacrylamide was polymerized from their surfaces by aqueous ATRP using several catalyst combinations. Very high grafting densities and molecular weights were achieved with good polydispersities. The brushes exhibited a strong repulsive force that increased with molecular weight in atomic force microscopy measurements. Hydrodynamic thicknesses were consistent with theory. Polymerization from these surfaces is very different from ATRP in solution and depends on monomer concentration in solution, type of catalyst, and surface initiator concentration. The observations were explained with an electrostatic model of the surface region that predicts an increase in the local concentration of Cu(I) and Cu(II) catalyst complexes.}, keywords = {ADSORPTION, BLOCK-COPOLYMERS, density, FORCE MICROSCOPE, INITIATED POLYMERIZATIONS, LAYER, MEDIA, POLYMERS, SELF-ASSEMBLED MONOLAYERS}, isbn = {0097-61560-8412-3854-5}, url = {://000183406500022}, author = {Kizhakkedathu, J. N. and Goodman, D. and Brooks, D. E.}, editor = {Matyjaszewski, K.} } @article {450, title = {Structural investigation of Silicalite-I loaded with n-hexane by X-ray diffraction, Si-29 MAS NMR, and molecular modeling}, journal = {Chemistry of Materials}, volume = {14}, number = {5}, year = {2002}, note = {ISI Document Delivery No.: 555JCTimes Cited: 23Cited Reference Count: 25}, month = {May}, pages = {2192-2198}, type = {Article}, abstract = {{The room temperature (298 K) structure of zeolite Silicalite-I loaded with approximately eight n-hexane molecules per unit cell was solved from twinned single-crystal X-ray diffraction (XRD) data in the monoclinic space group P12(1)/n1 with a = 19.8247(2) Angstrom}, keywords = {ADSORPTION, ALKANES, ENERGY-MINIMIZATION CALCULATIONS, LOCALIZATION, NAPHTHALENE, ORTHORHOMBIC FRAMEWORK, POWDER DIFFRACTION, SIMULATIONS, ZEOLITE H-ZSM-5, ZSM-5}, isbn = {0897-4756}, url = {://000175790100041}, author = {Morell, H. and Angermund, K. and Lewis, A. R. and Brouwer, D. H. and Fyfe, C. A. and Gies, H.} } @article {533, title = {Structure determination of Cu(410)-O using X-ray diffraction and DFT calculations}, journal = {Surface Science}, volume = {516}, number = {1-2}, year = {2002}, note = {ISI Document Delivery No.: 594AQTimes Cited: 12Cited Reference Count: 52}, month = {Sep}, pages = {16-32}, type = {Article}, abstract = {The Cu(4 1 0)-O surface, involving a 0.5 monolayer (ML) coverage of oxygen, is known to be extremely stable and a range of Cu(1 0 0) vicinal. surfaces facet to (4 1 0) in the presence of adsorbed oxygen. A new surface X-ray diffraction investigation of this surface has been conducted to determine its structure, and the detailed structural parameter values obtained are compared with the results of a density functional theory (DFT) calculation. The results show that the metal structure is unreconstructed, with the oxygen forming an overlayer with 0.25 ML O atoms at near-colinear step-edge sites and 0.25 NIL O atoms at mid-terrace hollow sites, approximately 0.6 Angstrom above the terraces. The large number of independent structural parameters potentially relevant to this vicinal surface presents a significant challenge for unique structural optimisation, but various missing row reconstruction models can be clearly excluded. Two detailed structural solutions are identified which give equally acceptable fits to the X-ray diffraction data after imposition of a Lennard-Jones penalty factor. These models differ especially in the O positions, but one is found to be more favoured by comparison with the results of the DFT calculations, and by considerations based on bond lengths and valence. Substantial relaxations from the bulk metal positions occur for the outermost Cu atoms; the ability of the vicinal surface to relax in this way may help to account for its stability compared with the missing row reconstruction induced by oxygen chemisorption on the Cu(1 0 0) surface. (C) 2002 Elsevier Science B.V. All rights reserved.}, keywords = {ADSORPTION, and, and topography, chemisorption, copper, CU(100), DETERMINATION, DIFFRACTION, ENERGY ION-SCATTERING, INITIO MOLECULAR-DYNAMICS, MISSING-ROW, MORPHOLOGY, OXYGEN, OXYGEN-INDUCED RECONSTRUCTION, RECONSTRUCTION, reflection, relaxation and reconstruction, roughness, SCANNING-TUNNELING-MICROSCOPY, SURFACE, surface structure, SURFACE-STRUCTURE, SURFACES, VICINAL COPPER SURFACES, vicinal single crystal, WAVE BASIS-SET, X-ray scattering}, isbn = {0039-6028}, url = {://000178027000003}, author = {Vlieg, E. and Driver, S. M. and Goedtkindt, P. and Knight, P. J. and Liu, W. and Ludecke, J. and Mitchell, K. A. R. and Murashov, V. and Robinson, I. K. and de Vries, S. A. and Woodruff, D. P.} } @article {405, title = {Synthesis and characterization of polymer brushes of poly(N,N-dimethylacrylamide) from polystyrene-latex by aqueous atom transfer radical polymerization}, journal = {Macromolecules}, volume = {35}, number = {11}, year = {2002}, note = {ISI Document Delivery No.: 554GUTimes Cited: 64Cited Reference Count: 51}, month = {May}, pages = {4247-4257}, type = {Article}, abstract = {Negatively charged polystyrene latex was synthesized, and a copolymer shell of 2-(methyl-2{\textquoteright}-chloropropionato)ethyl acrylate (HEA-Cl) and styrene was added, from which poly(N,N-dimethylacrylamide) (PDMA) was polymerized by atom transfer radical polymerization in aqueous suspension at room temperature. Increasing monomer concentration in the presence of CuCl or CuBr and one of three ligands (N,N,N{\textquoteright},N{\textquoteright},N"-pentamethyldiethylenetriamine (PMDETA), 1,1,4,7,10,10-hexamethyltriethylenetetramine (HMTETA), and tris [2-(dimethylamino)ethyl] amine (Me6TREN)) produced grafts whose molecular weight increased to over 600 000 and polydispersities in the range of 1.3-1.8, determined from chains recovered following cleavage by base. Hydrodynamic brush thicknesses were 70-800 nm, and average chain separations, calculated from M-n and the mass of polymer recovered per particle, varied from 4.0 to 1.1 nm. Very high grafting densities were achieved with good molecular weight control, the highest densities yet reported for high molecular weight polymer chains grown from a surface. Control of the polymerization was improved by addition of Cu(II) to enhance deactivation of free radicals, by including a low concentration of exogenous hydrophobic initiator at high monomer concentration and by reducing latex concentration. Increasing the concentration of exogenous initiator reduced graft thickness but eliminated control over the polydispersity. The unusual conditions required for optimization of the reaction and the observation of decreasing chain separation as M-n increased were explained by invoking a model of the particle surface that took into account the finite depth and high copolymer concentration of the region in which chains were initiated and particularly the fixed charges due to the sulfate initiator of shell copolymerization.}, keywords = {(METH)ACRYLAMIDES, ADSORPTION, AMBIENT-TEMPERATURE, BLOCK-COPOLYMERS, CARBOCATIONIC, FACILE, POLYELECTROLYTE BRUSHES, POLYMERIZATION, SELF-ASSEMBLED MONOLAYERS, SURFACE, SYNTHESIS, TETHERED CHAINS}, isbn = {0024-9297}, url = {://000175728100006}, author = {Jayachandran, K. N. and Takacs-Cox, A. and Brooks, D. E.} } @article {5117, title = {Tensor LEED analysis for the electrodeposited Pt(111)-(3x3)-Ag,I surface structure}, journal = {Surface Science}, volume = {490}, number = {3}, year = {2001}, note = {ISI Document Delivery No.: 473XWTimes Cited: 5Cited Reference Count: 34}, month = {Sep}, pages = {256-264}, type = {Article}, abstract = {A crystallographic analysis is reported using low-energy electron diffraction (LEED) in the tensor LEED approach for the electrodeposited coadsorption (3 x 3) structure with 4/9 monolayer (ML) of silver and 4/9 ML of iodine on the Pt(1 1 1) surface. The structure approximates a two-layer slice of bulk AgI cut parallel to its (1 1 1) plane and superimposed on the substrate with the Ag atoms in contact with the topmost Pt(1 1 1) layer, and the I atoms forming an overlayer on the Ag atoms. There are two types of Ag atoms in the (3 x 3) unit mesh; one type bonds to a single Pt atom, while the other type bonds to three Pt atoms. The average Ag-Pt bond distances are close to 2.48 and 2.82 (A) over circle respectively for the one and three-coordinate Ag atoms, but both types of Ag atoms bond to three I atoms with an average Ag-I distance of 2.67 (A) over circle. No significant corrugation is observed for either the I layer or the Ag layer. (C) 2001 Elsevier Science B.V. All rights reserved.}, keywords = {ADSORBATES, ADSORPTION, AG, chemisorption, ELECTROCHEMISTRY, ENERGY-ELECTRON-DIFFRACTION, IODINE, LOW ENERGY ELECTRON DIFFRACTION (LEED), METAL-SURFACES, platinum, PT(111), SCANNING-TUNNELING-MICROSCOPY, silver}, isbn = {0039-6028}, url = {://000171075300007}, author = {Labayen, M. and Harrington, D. A. and Saidy, M. and Mitchell, K. A. R.} } @article {4710, title = {Synthesis and characterization of AlPO4-36: a novel aluminophosphate molecular sieve with ATS structure}, journal = {Microporous and Mesoporous Materials}, volume = {32}, number = {3}, year = {1999}, note = {ISI Document Delivery No.: 261CDTimes Cited: 16Cited Reference Count: 32}, month = {Dec}, pages = {241-250}, type = {Article}, abstract = {AlPO-36, the parent member of the ATS, molecular sieve structure type, has been synthesized hydrothermally from gels containing only Al and P oxides. Four series of syntheses were carried out to determine the best conditions for the preparation of AlPO-36 free of AlPO-H3, Characterization of the synthesis products was performed using X-ray diffraction (XRD), chemical analysis, scanning electron microscopy (SEM), N-2 adsorption, X-ray photoelectron spectroscopy (XPS) and Al-27 and P-31 MAS NMR. X-ray powder diffraction patterns are comparable to those previously reported for MAPO-36. (C) 1999 Elsevier Science B.V. All rights reserved.}, keywords = {ADSORPTION, Al-27 and P-31 MAS NMR, AlPO-36, ATS structure type, FRAMEWORK TOPOLOGY, molecular sieves, scanning electron microscopy, SOLID-STATE NMR, THERMAL-STABILITY, VPI-5, WATER, XPS, XRD}, isbn = {1387-1811}, url = {://000083989500002}, author = {Zahedi-Niaki, M. H. and Xu, G. Y. and Meyer, H. and Fyfe, C. A. and Kaliaguine, S.} } @article {4656, title = {Tensor LEED analyses for three chemisorbed structures formed by iodine on a Pt(111) surface}, journal = {Surface Review and Letters}, volume = {6}, number = {5}, year = {1999}, note = {ISI Document Delivery No.: 300LQTimes Cited: 17Cited Reference Count: 406th International Conference on the Structure of Surfaces (ICSOS-6)JUL 26-30, 1999VANCOUVER, CANADAUniv British Columbia}, month = {Oct}, pages = {871-881}, type = {Proceedings Paper}, abstract = {Three distinct ordered iodine structures on a Pt(lll) surface have been studied with LEED crystallography in the coverage range 0.33-0.44 monolayers. These surfaces have translational symmetries of the ((root 3 x root 3)R30 degrees, (root 7 x root 7)R19.1 degrees and (3 x 3) types, and they all involve overlayer adsorption on the basically unreconstructed metal structures. The root 3 surface phase is indicated to have essentially all I atoms adsorbed at the regular threefold sites of the fee type (i.e. 3f sites), with no significant involvement by the corresponding sites of the hcp type (i.e. 3h sites). The root 7 structure has one I on an atop Pt site, and one each at 3f and 3h sites per unit mesh, while the (3 x 3) surface has one I on an atop site and three on bridge sites per unit mesh. The I corrugation is about 0.5 Angstrom for the root 7 structure, but is reduced to around 0.1 Angstrom at the (3 x 3) surface. The surface I-Pt bond lengths from these analyses show a general tendency to follow trends expected with the varying I coordination numbers. A preliminary discussion is given for uncertainties associated with some relaxations indicated in the metallic structures.}, keywords = {ADSORBATES, ADSORPTION, ELECTROCHEMISTRY, ENERGY-ELECTRON-DIFFRACTION, METAL-SURFACES, PT(100), RELIABILITY, RH(111), SCANNING TUNNELING MICROSCOPY, TRANSFORMATIONS}, isbn = {0218-625X}, url = {://000086254800043}, author = {Saidy, M. and Mitchell, K. A. R. and Furman, S. A. and Labayen, M. and Harrington, D. A.} } @article {4655, title = {Tensor LEED analysis for the Cu(111)-(root x root 7)R19.1 degrees-S surface structure}, journal = {Surface Science}, volume = {441}, number = {2-3}, year = {1999}, note = {ISI Document Delivery No.: 253RWTimes Cited: 11Cited Reference Count: 36}, month = {Nov}, pages = {425-435}, type = {Article}, abstract = {A tensor LEED analysis is reported for the (root 7 x root 7)R19.1 degrees structure formed by S at the Cu(lll)surface. A new structural model is found which corresponds to a modified version of the copper sulphide overlayer model first proposed by Domange and Oudar. In that model, the topmost layer has 3/7 monolayer each of Cu and S atoms, but the modification involves one S atom per unit mesh moving down to displace a Cu atom from the second metal layer. Relaxations among the topmost Cu atoms result in one S atom being effectively three-fold coordinate while the other two are sixfold coordinate and 12-fold coordinate: the averaged S-Cu bond lengths are indicated to equal 2.19, 2.47 and 2.62 Angstrom respectively. Some discussion is included of factors that may influence this choice of surface structure. (C) 1999 Elsevier Science B.V. All rights reserved.}, keywords = {ADSORPTION, chemisorption, copper, ENERGY-ELECTRON-DIFFRACTION, LAYERS, low energy electron diffraction, LOW INDEX SINGLE CRYSTAL, METAL-SURFACES, MOLECULE, RAY STANDING-WAVE, RECONSTRUCTION, RU(0001), SUBSTRATE, SULFUR, sulphur, SURFACE, surface reconstruction}, isbn = {0039-6028}, url = {://000083570400024}, author = {Saidy, M. and Mitchell, K. A. R.} } @article {4351, title = {Water-soluble cavitands: Synthesis of methylene-bridged resorcin[4]arenes containing hydroxyls and phosphates at their feet and bromomethyls and thiomethyls at their rims}, journal = {Journal of Organic Chemistry}, volume = {63}, number = {20}, year = {1998}, note = {ISI Document Delivery No.: 127ZGTimes Cited: 11Cited Reference Count: 31}, month = {Oct}, pages = {6824-6829}, type = {Article}, abstract = {The synthesis of rim-functionalized methylene-bridged resorcin[4]arenes ("cavitands") containing hydrophilic propanol or water-solublilizing propylphosphate feet is described. The cavitands possess the synthetically useful benzylthiol (cavitands 6 and 16) or benzylbromide (cavitands 9 and 11) functionalities at their rims, which are suitable for further derivatization near the hydrophobic cavity of the cavitand. These water-soluble cavitands represent new building blocks that are ideal for use in aqueous supramolecular chemistry. As an example of their synthetic utility in supramolecular studies, we have reacted phosphate-footed cavitands 11 and 16 with cysteine-containing peptide 17 and chloroacetylated peptide 19, respectively, to afford the corresponding de novo proteins 18 and 20.}, keywords = {ADSORPTION, BUILDING-BLOCKS, CARCERANDS, ENCAPSULATION, HOST-GUEST COMPLEXATION, MOLECULAR, PHASE, RECOGNITION, RESORCINARENES, SELF-ASSEMBLED MONOLAYERS}, isbn = {0022-3263}, url = {://000076380300019}, author = {Mezo, A. R. and Sherman, J. C.} } @article {4330, title = {XPS studies of the nitridation of MoO3 thin films on alumina and silica supports}, journal = {Applied Surface Science}, volume = {136}, number = {3}, year = {1998}, note = {ISI Document Delivery No.: 140QWTimes Cited: 3Cited Reference Count: 40}, month = {Nov}, pages = {178-188}, type = {Article}, abstract = {X-ray photoelectron spectroscopy has been used to characterize thin films of MoO3 formed on planar oxidized supports, namely AlOx (from aluminum strip) and SiO2 (from silicon wafer). Comparisons are made with behaviour for MoO3 on metallic Mo substrate. It is observed that on calcination at 450 degrees C, the Mo 3d spectral features shift to higher binding energy for MoO3/AlOx and to lower binding energy for MoO3/SiO2, On nitridation by heating in NH3, it is found that the samples on the oxide supports show easier O-N replacement compared with the MoO3/Mo system. In general, the nitridation behaviour for MoO3/AlO, is similar to that of MoO3/Mo, but Mo species in MoO3/SiO2 seem to be more easily reduced (Mo(0) is detected for the SiO2 system but not for AlOx). Comparisons of heating rates for the second nitridation step from 350 to 450 degrees C were made for the MoO3/Mo and MoO3/AlOx samples. Differences between the high heating rate (100 K/h) and the low heating rate (40 K/h) are incremental but definite. The lower heating rate is favourable both for the O-N replacement and for the metal reduction. For example, more Mo(+3) is present after the nitridation to 450 degrees C when the low-heating rate regime is used, compared with that formed when the heating is done at the higher rate. (C) 1998 Elsevier Science B.V. All rights reserved.}, keywords = {ADSORPTION, BEHAVIOR, CARBIDE, HYDRODENITROGENATION CATALYSTS, HYDRODESULFURIZATION, MOLYBDENUM NITRIDE, MoO3 thin films, nitridation, QUINOLINE, SITES, SURFACE-AREA, THIOPHENE, X-ray photoelectron, X-ray photoelectron spectroscopy}, isbn = {0169-4332}, url = {://000077100700002}, author = {Leung, Y. L. and Wong, P. and Zhou, M. Y. and Mitchell, K. A. R. and Smith, K. J.} } @article {4331, title = {X-ray photoelectron spectroscopy studies of the reduction of MoO3 thin films by NH3}, journal = {Applied Surface Science}, volume = {136}, number = {1-2}, year = {1998}, note = {ISI Document Delivery No.: 133ZGTimes Cited: 7Cited Reference Count: 33}, month = {Oct}, pages = {147-158}, type = {Article}, abstract = {X-ray photoelectron spectroscopy (XPS) has been used to gain insight into surface reaction pathways associated with the nitridation by NH3 of MoO3 thin films grown on metallic substrates. The samples formed can be seen as model hydrodenitrogenation (HDN) catalysts, but the more-controlled surface morphology allows spectral features to be studied in the absence of charging effects that can interfere with such measurements on high-area samples. Observed core level and valence spectra are consistent with the MoO3 being reduced, but the degree of reduction depends on the reaction temperature. Heating to 350 degrees C indicates some conversion to Mo(+5) and {\textquoteright}O-rich{\textquoteright} Mo(+4) components, while heating to 450 degrees C and to 700 degrees C give respectively a {\textquoteright}N-rich{\textquoteright} Mo(+4) form and a Mo(+3) oxynitride as the dominant components. It is concluded that the nitridation of MoO3 by NH3 involves initial hydrogenation, with subsequent elimination of water, and the effective replacement of O by N as the reduction continues. Surface compositions determined here during the nitridation process contrast with conclusions reached previously for the evolution of bulk phases as deduced by X-ray diffraction. (C) 1998 Elsevier Science B.V. All rights reserved.}, keywords = {ADSORPTION, ammonia, Auger, CATALYSTS, DECOMPOSITION, HYDRODENITROGENATION, MOLYBDENUM NITRIDES, MOO3, NH3, REDUCTION, SURFACE-AREA, X-ray photoelectron spectroscopy, XPS}, isbn = {0169-4332}, url = {://000076717000022}, author = {Leung, Y. L. and Wong, P. C. and Mitchell, K. A. R. and Smith, K. J.} } @article {3809, title = {Boundary condition effects in simulations of water confined between planar walls}, journal = {Molecular Physics}, volume = {88}, number = {2}, year = {1996}, note = {ISI Document Delivery No.: UN985Times Cited: 86Cited Reference Count: 32}, month = {Jun}, pages = {385-398}, type = {Article}, abstract = {In computer simulations of water between hydrophobic walls the results exhibit a strong dependence upon the boundary conditions applied. With the minimum image (MI) convention the water molecules tend to be orientationally ordered throughout the simulation cell (Valleau, J. P., and Gardner, A. A., 1987, J. chem. Phys., 86, 4162) whereas, if a spherical cut-off (SC) is applied, strong orientational order is found only in the immediate vicinity of the surface (Lee, C. Y., McCammon, J. A., and Rossky, P. J., 1984, J. chem. Phys., 80, 4448). These conflicting observations have remained unresolved, and clearly raise troubling questions concerning the validity of simulation results for water between surfaces of all types. In the present paper we explore this problem by carrying out a detailed analysis of the results obtained with various types of boundary condition. These include Ewald calculations carried out with a central simulation cell adapted to describe the slab geometry of interest. It is shown that the order observed in MI calculations is an artefact of that particular truncation. The reason for this is isolated and discussed. Similar problems are found if a cylindrical cut-off is employed. The Ewald and SC methods gave qualitatively similar results for systems similar to those considered in previous simulations. However, for some geometries problems can also arise with the SC method. We conclude that in general the slab-adapted Ewald method is the safest choice.}, keywords = {ADSORPTION, CHARGED ELECTRODES, COMPUTER-SIMULATION, IONS, LIQUID WATER, METAL WALLS, models, MOLECULAR-DYNAMICS SIMULATION, MONTE-CARLO SIMULATIONS, SURFACE}, isbn = {0026-8976}, url = {://A1996UN98500006}, author = {Shelley, J. C. and Patey, G. N.} } @article {3838, title = {Poly(ethylene glycol) amphiphile adsorption and liposome partition}, journal = {Journal of Chromatography B-Biomedical Applications}, volume = {680}, number = {1-2}, year = {1996}, note = {ISI Document Delivery No.: UQ821Times Cited: 4Cited Reference Count: 649th International Conference on Partitioning in Aqueous 2-Phase Systems - Advances in the Use of Polymers in Cell Biology, Biotechnology and Environmental SciencesJUN 04-09, 1995ZARAGOZA, SPAIN}, month = {May}, pages = {145-155}, type = {Proceedings Paper}, abstract = {Surface localized poly(ethylene glycol) (PEG) amphiphiles of type C-16:0-EO(151) and C-18:2-EO(1.51) were studied via ellipsometry at macroscopic, hat methylated silica (MeSi), phosphatidic acid (PA), and phosphatidylcholine (PC) surfaces. At these surfaces the amphiphiles adsorb similarly, in a non-cooperative manner, achieving a plateau (approximate to 0.1 PEG chains/nm(2)) well below amphiphile critical micelle concentration (CMC). The resultant PEG-enriched layers were 10-15 nm thick, with a polymer concentration (approximate to 0.07 g/cm(3)) greater than the PEG-enriched phase of many dextran, PEG aqueous two-phase systems. PEG-amphiphile adsorption (mg/m(2)) at hydrophobic and phospholipid flat surfaces correlated with changes in the partition (log K) of PC liposomes in such two-phase systems. PEG-amphiphile adsorption at macroscopic surfaces appears to represent a balance between hydrophobic attraction and repulsive intra-chain interactions which promote chain elongation normal to the surface.}, keywords = {ADSORPTION, AQUEOUS 2-PHASE SYSTEMS, BEHAVIOR, CELL-SEPARATION, critical micelle concentration, ellipsometry, HYDROPHOBIC AFFINITY PARTITION, LIPOSOMES, partitioning, PHASE SYSTEMS, poly(ethylene glycol) (PEG), polymer, PROTEINS, SURFACE-PROPERTIES, WATER-INTERFACE}, isbn = {0378-4347}, url = {://A1996UQ82100016}, author = {VanAlstine, J. M. and Malmsten, M. and Brooks, D. E.} } @article {3488, title = {A STRUCTURAL STUDY OF PD/CU(100) SURFACE ALLOYS}, journal = {Surface Science}, volume = {337}, number = {1-2}, year = {1995}, note = {ISI Document Delivery No.: RQ749Times Cited: 33Cited Reference Count: 54}, month = {Aug}, pages = {79-91}, type = {Article}, abstract = {The structures formed by one-half and one monolayer (ML) of Pd evaporated onto Cu(100) at 300 K were studied by low energy electron diffraction (LEED), medium energy ion scattering (MEIS), thermal desorption spectroscopy (TDS), and embedded atom method (EAM) calculations. In the half monolayer case, the LEED I(E) curves are consistent with the established c(2 x 2) surface alloy model. The MEIS data, however, suggest that a fraction of the Pd (similar to 1/4) is in {\textquoteright}{\textquoteright}second layer{\textquoteright}{\textquoteright} sites, in agreement with previous LEIS, TDS and XPS forward scattering measurements. The EAM simulations support the formation of alloy islands, providing a mechanism for the covering of some Pd atoms. As the deposition proceeds, however, this island formation is indicated to occur preferentially over clean copper. In the one monolayer case, a p(2 x 2)-p4g LEED pattern is observed. Analysis of the I(E) curves suggests that this arises from (100) Pd packed above the c(2 x 2) alloy. EAM calculations confirm the stability of this model. Evidence from MEIS and TDS, however, shows that the one monolayer surface as prepared in this work is inhomogeneous. c(2 x 2) and Cu rich surface domains exist in addition to those having the p4g Pd/c(2 x 2)PdCu structure.}, keywords = {(MEIS), ABSORPTION FINE-STRUCTURE, ADSORPTION, CU(100), DIFFRACTION, GROWTH, HYDROGEN, ION-SCATTERING, LOW ENERGY ELECTRON DIFFRACTION (LEED), LOW-ENERGY ELECTRON, MEDIUM ENERGY ION SCATTERING, molecular dynamics, RECONSTRUCTION, SPECTROSCOPY, surface structure, THERMAL DESORPTION, ULTRATHIN PD FILMS}, isbn = {0039-6028}, url = {://A1995RQ74900017}, author = {Pope, T. D. and Vos, M. and Tang, H. T. and Griffiths, K. and Mitchell, I. V. and Norton, P. R. and Liu, W. and Li, Y. S. and Mitchell, K. A. R. and Tian, Z. J. and Black, J. E.} } @article {3201, title = {BOND-LENGTH INEQUALITIES AND RELAXATIONS AT THE RH(110)-C(2X2)-S SURFACE-STRUCTURE STUDIED BY LEED CRYSTALLOGRAPHY}, journal = {Surface Science}, volume = {304}, number = {3}, year = {1994}, note = {ISI Document Delivery No.: MZ811Times Cited: 8Cited Reference Count: 19}, month = {Mar}, pages = {L481-L487}, type = {Letter}, abstract = {A tensor LEED analysis has been made for the Rh(110)-c(2 x 2)-S surface structure using intensity-versus-energy curves measured for twelve independent beams at normal incidence. Each S atom chemisorbs on a centre site of the Rh(110) surface. It bonds to the second layer Rh atom directly below, with a bond distance equal to about 2.27 angstrom, and to four neighbouring first layer Rh atoms at close to 2.47 angstrom. A significant feature of this structure is that the second metal layer is buckled; those Rh atoms directly below the S atoms relax down by about 0.11 angstrom compared with the other second layer Rh atoms. This buckling is apparently driven by the need to reduce the difference that would otherwise occur between these two types of S-Rh bond lengths. A component in the observed difference between the S-Rh distances appears to be dependent on the metallic coordination number for the Rh atoms; in this regard, a comparison is made with the structural details for O chemisorbed on reconstructed Ni(110).}, keywords = {ADSORPTION, ENERGY-ELECTRON-DIFFRACTION, RECONSTRUCTION}, isbn = {0039-6028}, url = {://A1994MZ81100007}, author = {Wong, K. C. and Mitchell, K. A. R.} } @article {3187, title = {TENSER LEED ANALYSIS OF THE PD(100)-(ROOT-5X-ROOT-5)R27-DEGREES-O SURFACE-STRUCTURE}, journal = {Surface Science}, volume = {318}, number = {1-2}, year = {1994}, note = {ISI Document Delivery No.: PL286Times Cited: 29Cited Reference Count: 29}, month = {Oct}, pages = {129-138}, type = {Article}, abstract = {A tenser LEED analysis of the Pd(100)-(root 5 x root 5)R27 degrees-O surface structure supports a surface oxide model, as first postulated by Orent and Bader. The detailed model which gives the best correspondence with experimental intensity data has a PdO(001) overlayer stacked on to the Pd(100) surface such that rumpling is induced in both the oxide and topmost Pd(100) layers. The structure can be seen as representing a compromise between the drive toward an ideally flat PdO(001) surface and the need to optimize total bonding at the surface. Pd atoms in the topmost Pd(100) layer appear to displace laterally to minimize corrugations in the top metal layers. The total corrugations in the PdO overlayer and the first Pd(100) layer are indicated to be about 0.26 and 0.51 Angstrom, respectively. The average O-Pd bond length for two-coordinate O on the Pd surface (1.73 Angstrom) remains dose to the predicted value of 1.76 Angstrom based on the structure of bulk PdO.}, keywords = {ADSORPTION, desorption, ENERGY-ELECTRON-DIFFRACTION, HYDROGEN, OXYGEN, PD(100) SURFACE, PHASE, RECONSTRUCTION}, isbn = {0039-6028}, url = {://A1994PL28600019}, author = {Vu, D. T. and Mitchell, K. A. R. and Warren, O. L. and Thiel, P. A.} } @article {2718, title = {CAVITATION OF A LENNARD-JONES FLUID BETWEEN HARD WALLS, AND THE POSSIBLE RELEVANCE TO THE ATTRACTION MEASURED BETWEEN HYDROPHOBIC SURFACES}, journal = {Journal of Chemical Physics}, volume = {98}, number = {9}, year = {1993}, note = {ISI Document Delivery No.: LA763Times Cited: 106Cited Reference Count: 26}, month = {May}, pages = {7236-7244}, type = {Article}, abstract = {A Lennard-Jones fluid confined between two planar hard walls is simulated using grand canonical Monte Carlo, and capillary evaporation is found for liquid subcritical bulk states. General methods are given for simulating a metastable fluid beyond coexistence. For the systems studied, the liquid and the gas phases coexist in equilibrium at a separation of approximately 5 diam, the spinodal cavitation separation is at approximately 4 diam, and the spinodal condensation separation is at greater-than-or-similar-to 15 diam. The interaction pressure between the walls is found to be attractive and increases rapidly as the spinodal separation is approached. On the equilibrium liquid branch, the net pressure still appears significantly larger than the van der Waals attraction at separations of approximately 10 diam. A simple analytic theory is given, which relates the force to the approach of the separation-induced phase transition. It is suggested that this is the microscopic origin of the measured attractions between hydrophobic surfaces in water.}, keywords = {ADSORPTION, AQUEOUS-ELECTROLYTE SOLUTIONS, FILMS, FORCES, MONTE-CARLO, PHASE-EQUILIBRIA, SLIT}, isbn = {0021-9606}, url = {://A1993LA76300069}, author = {Berard, D. R. and Attard, P. and Patey, G. N.} } @article {2928, title = {XPS STUDIES OF THE STABILITY AND REACTIVITY OF THIN-FILMS OF OXIDIZED ZIRCONIUM}, journal = {Applied Surface Science}, volume = {72}, number = {3}, year = {1993}, note = {ISI Document Delivery No.: MF104Times Cited: 21Cited Reference Count: 32}, month = {Nov}, pages = {237-244}, type = {Article}, abstract = {X-ray photoelectron spectroscopy (XPS) has been used to characterize thin films formed by the deposition of zirconium on to gold foil. With deposition rates of the order of 1 angstrom min-1, in the presence of an atmosphere of 10(-9) mbar H2O, the film has an outer region Of ZrO2 and inner regions of a lower oxidation state material, ZrO(x), and Zr-Au alloy. Initially both ZrO(x) and Zr-Au alloy are oxidized by either H2O or O2 at 300-degrees-C, although this process is hindered as the ZrO2 layer gets thicker. However, even with the protective oxide layer, heating in 5 x 10(-7) mbar D2 (with a partial pressure of 10(-9) mbar H2O) can convert ZrO(x) to ZrO2, a reaction apparently facilitated by migrating D atoms.}, keywords = {ADSORPTION, AES, BINDING-ENERGY SHIFTS, electron, HYDROGEN, OXIDATION, OXYGEN, RAY PHOTOELECTRON-SPECTROSCOPY, SINGLE-CRYSTAL, SURFACES, ZR}, isbn = {0169-4332}, url = {://A1993MF10400004}, author = {Wang, Y. M. and Li, Y. S. and Wong, P. C. and Mitchell, K. A. R.} } @article {7315, title = {A LEED CRYSTALLOGRAPHIC ANALYSIS FOR THE C(2X2) SURFACE-STRUCTURE FORMED BY THE CHEMISORPTION OF PH3 ON THE RH(100) SURFACE}, journal = {Surface Science}, volume = {268}, number = {1-3}, year = {1992}, note = {ISI Document Delivery No.: HR728Times Cited: 5Cited Reference Count: 26}, month = {May}, pages = {L274-L278}, type = {Letter}, abstract = {An analysis with low-energy electron diffraction (LEED) is reported for the c(2 x 2) structure obtained by the adsorption and dissociation of PH3 on the Rh(100) surface. Intensity-versus-energy curves measured for 12 independent beams were compared with those from multiple scattering calculations for overlayer structural models in which the metal atoms remain in their regular bulk positions. The best correspondence between the two sets of beam intensities occurs with P atoms chemisorbed in the "expected" 4-coordinate bonding sites, and with the nearest-neighbour P-Rh bond distance equal to 2.13 angstrom.}, keywords = {ADSORPTION, CHEMISTRY, CO, H-2, PHOSPHORUS-CONTAINING MOLECULES, PREADSORBED PHOSPHORUS}, isbn = {0039-6028}, url = {://A1992HR72800006}, author = {Lou, J. R. and Mitchell, K. A. R.} } @article {7249, title = {LEED CRYSTALLOGRAPHIC STUDIES FOR THE CU(110)-(2 X 3)-N SURFACE-STRUCTURE}, journal = {Surface Science}, volume = {271}, number = {3}, year = {1992}, note = {ISI Document Delivery No.: JA639Times Cited: 19Cited Reference Count: 31}, month = {Jun}, pages = {519-529}, type = {Article}, abstract = {An initial multiple-scattering analysis of LEED intensities has been performed for the Cu(110)-(2 x 3)-N surface structure. R-factor analysis supports neither simple N overlayer models nor models with Cu(100)-type top-layer reconstructions. The best correspondence between calculated and experimental intensities appears with models where every other [001] row is missing, similar to that observed for the Cu(110)-(2 x 1)-O surface. The favoured surface structure has N atoms chemisorbed on long-bridge sites such that chains of (Cu(a)-N-Cu(b)-N-Cu(a))x create a surface analogous to the ideal Cu3N(110) surface, except that every third N atom is missing from the surface chains. There is evidence that lateral displacement of copper atoms from the ideal positions leads to two different N-Cu surface bond lengths with values near 1.83 and 1.90 angstrom. Each N atom also bonds to two Cu atoms in the second layer with equal bond lengths of about 1.88 angstrom.}, keywords = {ADSORPTION, AES, chemisorption, CU(110)(2X3)-N STRUCTURE, ENERGY ELECTRON-DIFFRACTION, NI(110), NITRIDE, NITROGEN, RECONSTRUCTION, SITE}, isbn = {0039-6028}, url = {://A1992JA63900025}, author = {Grimsby, D. T. V. and Zhou, M. Y. and Mitchell, K. A. R.} }