Modification of silica surfaces by grafting of alkyl chains. I — Characterization of silica surfaces by inverse gas-solid chromatography at zero surface coverage

1987 ◽  
Vol 23 (2) ◽  
pp. 121-128 ◽  
Author(s):  
A. Vidal ◽  
E. Papirer ◽  
Wang Meng Jiao ◽  
J. B. Donnet
Keyword(s):  
Surface Coverage ◽  
Alkyl Chains ◽  
Silica Surfaces

Synthesis and characterization of a novel long-alkyl-chain ester-substituted benzimidazole gelator and its octan-1-ol solvate

2017 ◽  
Vol 73 (4) ◽  
pp. 350-356 ◽  
Author(s):  
H. Cristina Geiger ◽  
Patricia L. Zick ◽  
William R. Roberts ◽  
David K. Geiger
Keyword(s):  
Hydrogen Bonds ◽  
Surface Coverage ◽  
Alkyl Chain ◽  
Benzimidazole Derivative ◽  
Aromatic Rings ◽  
Alkyl Chains ◽  
Solvent Molecules ◽  
Chain Ester ◽  
Long Alkyl Chain

The synthesis of a novel benzimidazole derivative with a long-chain-ester substituent, namely methyl 8-[4-(1H-benzimidazol-2-yl)phenoxy]octanoate, (3), is reported. Ester (3) shows evidence of aggregation in solution and weak gelation ability with toluene. The octan-1-ol solvate, methyl 8-[4-(1H-benzimidazol-2-yl)phenoxy]octanoate octan-1-ol monosolvate, C22H26N2O3·C8H18O, (4), exhibits a four-molecule hydrogen-bonded motif in the solid state, with N—H...O hydrogen bonds between benzimidazole molecules and O—H...N hydrogen bonds between the octan-1-ol solvent molecules and the benzimidazole unit. The alkyl chains of the ester and the octan-1-ol molecules are in unfolded conformations. The phenylene ring is canted by 10.27 (6)° from the plane of the benzimidazole ring system. H...C contacts make up 20.7% of the Hirshfeld surface coverage. Weak C—H...π interactions involving the benzimidazole alkyl chain and three aromatic rings are observed.

scholarly journals Crystal structure of thermostable alkylsulfatase SdsAP from Pseudomonas sp. S9

2017 ◽  
Vol 37 (3) ◽  
Author(s):  
Lifang Sun ◽  
Pu Chen ◽  
Yintao Su ◽  
Zhixiong Cai ◽  
Lingwei Ruan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Sodium Dodecyl ◽  
Titration Calorimetry ◽  
Pseudomonas Sp ◽  
Sterol Carrier Protein ◽  
Dimerization Domain ◽  
Alkyl Chains ◽  
Hydrolysis Of

A novel alkylsulfatase from bacterium Pseudomonas sp. S9 (SdsAP) was identified as a thermostable alkylsulfatases (type III), which could hydrolyze the primary alkyl sulfate such as sodium dodecyl sulfate (SDS). Thus, it has a potential application of SDS biodegradation. The crystal structure of SdsAP has been solved to a resolution of 1.76 Å and reveals that SdsAP contains the characteristic metallo-β-lactamase-like fold domain, dimerization domain, and C-terminal sterol carrier protein type 2 (SCP-2)-like fold domain. Kinetic characterization of SdsAP to SDS by isothermal titration calorimetry (ITC) and enzymatic activity assays of constructed mutants demonstrate that Y246 and G263 are important residues for its preference for the hydrolysis of ‘primary alkyl’ chains, confirming that SdsAP is a primary alkylsulfatase.

Formation Of Single-Wall Carbon Nanotubes Forrest Assemblies On Metal Surfaces

2002 ◽  
Vol 734 ◽  
Author(s):  
Debjit Chattopadhyay ◽  
Izabela Galeska ◽  
Fotios Papadimitrakopoulos
Keyword(s):  
Carbon Nanotubes ◽  
Surface Coverage ◽  
Iron Hydroxide ◽  
Growth Characteristics ◽  
Self Organization ◽  
Single Wall Carbon Nanotubes ◽  
Unique Challenge ◽  
Single Wall Carbon ◽  
Topological Characteristics

ABSTRACTLearning how to purify and manipulate single wall carbon nanotubes (SWNTs) presents a unique challenge in material science. The processing-related difficulties of these long nano-fibers stem from their high aspect ratio, rigidity and the profound hydrophobic attractions along their tubular walls. Shortening them into discrete segments, with lengths from tens to hundreds of nanometers, presents a viable methodology to alleviate the shape-induced intractability. In addition, the metal-assisted self-organization of these nanosized objects into nano-forest geometries with dense perpendicular surface grafting, demonstrates that such nanosized objects hold significant promise for the development of nanoscale devices. This paper will present an extensive characterization of the topological characteristics of these assemblies, along with their surface coverage, growth characteristics and height fluctuation on iron hydroxide substrates.

Determination of the Orientation of Silanes on Silica Surfaces by Fourier Transform Infrared Photoacoustic Spectroscopy

1986 ◽  
Vol 40 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Marek W. Urban ◽  
Jack L. Koenig
Keyword(s):  
Fourier Transform ◽  
Photoacoustic Spectroscopy ◽  
Surface Coverage ◽  
Silica Surface ◽  
Fourier Transform Infrared ◽  
Coupling Agents ◽  
Surface Hydroxyl ◽  
Silica Surfaces ◽  
Quantitative Surface Analysis ◽  
Infrared Photoacoustic Spectroscopy

Fourier transform infrared photoacoustic spectroscopy has been used for quantitative surface analysis of silica treated with trifunctional coupling agents such as γ-Methacryloxypropyltriethoxysilane (γ-MPS), γ-Glycidoxypropyltrimethoxysilane (γ-GPS), and γ-Aminopropyltri-ethoxysilane (γ-APS). The calibration curves are obtained for several characteristic bands of the coupling agents. Using a highly polarizable gas in the photoacoustic cell and comparing the spectra with a nonpolarizable coupling gas, it is possible to evaluate orientation of the coupling agents on the silica surface. The type of orientation is a function of the extent of surface coverage. At low surface coverage, coupling agents tend to take a perpendicular orientation with respect to the surface, and increasing surface coverage leads to parallel orientation. Increasing the coupling agent concentration also causes orientational changes of the species which form chemical bonds with the silica surface (hydroxyl, water, and carbonyl groups).

scholarly journals Characterization of nanomedicines’ surface coverage using molecular probes and capillary electrophoresis

2018 ◽  
Vol 130 ◽  
pp. 48-58 ◽  
Author(s):  
J.-B. Coty ◽  
F. Varenne ◽  
A. Benmalek ◽  
O. Garsaa ◽  
I. Le Potier ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Surface Coverage ◽  
Molecular Probes

Characterization of immobilized antibodies on silica surfaces

1988 ◽  
Vol 35 (6) ◽  
pp. 466-471 ◽  
Author(s):  
Jinn-Nan Lin ◽  
J. Herron ◽  
J.D. Andrade ◽  
M. Brizgys
Keyword(s):  
Silica Surfaces ◽  
Immobilized Antibodies

Production and Characterization of Deposited Mono-Sized Clusters

1990 ◽  
Vol 206 ◽  
Author(s):  
Donald M. Cox ◽  
Barbara Kessler ◽  
Pierre Fayet ◽  
Wolfgang Eberhardt ◽  
Rex D. Sherwood ◽  
...  
Keyword(s):  
Cluster Size ◽  
Surface Coverage ◽  
Metal Clusters ◽  
High Energy ◽  
Cluster Ions ◽  
Rare Gas ◽  
Ion Sputtering ◽  
Transition Metal Clusters ◽  
X Ray

ABSTRACTUsing high energy rare gas ion sputtering of metal targets, we are able to produce nanoamps of mass selected transition metal clusters. Mono-sized cluster ions are deposited at low kinetic energy upon substrates, e.g. silica or carbon, and are then characterized using UV and x-ray photoemission. In this paper we will discuss photoemission measurements of the 4f7/2 core level energies of Au (1–5,7 atom samples) clusters deposited on silica. From such studies we are beginning to understand how electronic structure, cluster stability and mobility depend on (deposited) cluster size, surface coverage, and substrate temperature.

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