Analysis of Protonation Mechanisms for Models of Surface Complexes of N-(Propyl)ethylenediaminetriacetic Acid with Silica

2021 ◽  
Vol 2021 (8) ◽  
pp. 924-929
Author(s):  
I. A. Babina ◽  
B. S. Vorontsov ◽  
V. V. Moskvin ◽  
I. N. Grekhov ◽  
A. O. Babin
Keyword(s):  
Surface Complexes

Immunogold and immunoblot studies on a cell surface protein found in primary mesenchyme cells and in the cortical secretory vesicles of the sea urchin egg

1987 ◽  
Vol 45 ◽  
pp. 832-833
Author(s):  
G.L. Decker ◽  
M.C. Valdizan
Keyword(s):  
Cell Surface ◽  
Sea Urchin ◽  
Surface Protein ◽  
Egg Cell ◽  
Secretory Vesicles ◽  
Cell Surface Protein ◽  
Surface Complexes ◽  
Mesenchyme Cells ◽  
Lowicryl K4m ◽  
Primary Mesenchyme Cells

A monoclonal antibody designated MAb 1223 has been used to show that primary mesenchyme cells of the sea urchin embryo express a 130-kDa cell surface protein that may be directly involved in Ca2+ uptake required for growth of skeletal spicules. Other studies from this laboratory have shown that the 1223 antigen, although in relatively low abundance, is also expressed on the cell surfaces of unfertilized eggs and on the majority of blastomeres formed prior to differentiation of the primary mesenchyme cells.We have studied the distribution of 1223 antigen in S. purpuratus eggs and embryos and in isolated egg cell surface complexes that contain the cortical secretory vesicles. Specimens were fixed in 1.0% paraformaldehyde and 1.0% glutaraldehyde and embedded in Lowicryl K4M as previously reported. Colloidal gold (8nm diameter) was prepared by the method of Mulpfordt.

Uranyl Surface Complexes Formed on Subsurface Media from DOE Facilities

2002 ◽  
Vol 66 (1) ◽  
pp. 99 ◽  
Author(s):  
Benjamin C. Bostick ◽  
Scott Fendorf ◽  
Mark O. Barnett ◽  
Phillip M. Jardine ◽  
Scott C. Brooks
Keyword(s):  
Surface Complexes

O-O bond activation with cobalt(II)-ethylenediamine complexes in ion-exchange resins

1980 ◽  
Vol 45 (6) ◽  
pp. 1780-1784 ◽  
Author(s):  
Atanas Andreev ◽  
Lachezar Prahov ◽  
Dimitar Shopov
Keyword(s):  
Ion Exchange ◽  
Bond Activation ◽  
Catalytic Properties ◽  
Decomposition Reaction ◽  
Ion Exchange Resins ◽  
Hydrogen Peroxide Decomposition ◽  
Surface Complexes ◽  
Peroxide Decomposition ◽  
Epr Parameters ◽  
Exchange Resins

The formation of Oxygen paramagnetic adducts of Co(II) containing ion-exchange resins in the presence of adsorbed ethylenediamine has been found. The EPR parameters of a complex of the type Co(III) (en)2O-2 and of O-2 species formed in the presence of Co(en)2+3 have been described. The catalytic properties of Co-ethylenediamine surface complexes with respect to the hydrogen peroxide decomposition reaction have been investigated and a probable mechanism has been suggested.

scholarly journals Multiplicity of Active-Site in Heterogeneous Ziegler-Natta Catalyst and Its Correlation with Polymer Microstructure

1970 ◽  
Vol 46 (4) ◽  
pp. 487-494
Author(s):  
ATM Kamrul Hasan
Keyword(s):  
Molecular Weight ◽  
Computer Simulation ◽  
Active Site ◽  
Photoelectron Spectroscopy ◽  
Active Sites ◽  
Chain Structure ◽  
Surface Complexes ◽  
Polymer Microstructure ◽  
Natta Catalyst ◽  
Ziegler Natta Catalyst

Multiplicity of active-site in heterogeneous Ziegler-Natta catalysts and its correlation with polymer microstructure was studied through the surface structure analysis of catalyst by computer simulation of X-ray Photoelectron Spectroscopy (XPS) data and microstructure investigation of polypropylene chains based on the deconvolution of the molecular weight distribution curves by multiple Flory most probable distributions using Gel Permeation Chromatography (GPC) method. The number and relative intensities of these peaks were found correlated to the distribution of multiple active sites. In this investigation, four individual categories of active sites were identified, each of which yields polypropylene with unique properties of molecular weight and chain structure different from other active sites. The reason of the multiplicity of active sites was determined by the presence of different locations of surface titanium species coordinated with other surface atoms or molecules. These different surface complexes of active species determine the multiple active site nature of catalyst which replicates the microtacticity, molecular weight and chain microstructure distribution of polymer. Keywords: Ziegler-Natta catalyst; Multiple active sites; Flory components; Computer simulation; Deconvolution; MWD. DOI: http://dx.doi.org/10.3329/bjsir.v46i4.9596 BJSIR 2011; 46(4): 487-494

scholarly journals Platinum surface complexes as precursors for H2–O2 recombination catalysts

2017 ◽  
Vol 35 (7-8) ◽  
pp. 735-743 ◽  
Author(s):  
Olesya B Volovenko ◽  
Olga A Zaporozhets ◽  
Vladyslav V Lisnyak ◽  
Olga Yu Boldyrieva
Keyword(s):  
Silica Gel ◽  
Platinum Metal ◽  
Langmuir Model ◽  
Ammonium Salts ◽  
Platinum Surface ◽  
Chloride Complexes ◽  
Surface Complexes ◽  
Acidic Solutions ◽  
Modified Surface ◽  
Excellent Stability

In this work, the adsorption of platinum (II, IV) chloride complexes from acidic solutions on silica gel modified with quaternary ammonium salts (QAS) was studied. The uptake of the platinum chloride complexes is caused by the formation of ionic (QAS+)2[PtCl x]2− ( x = 4, 6) associates on the surface of silica gel. The isotherms of adsorption are fitted by the Langmuir model. The maximum capacity for [PtCl4]2− and [PtCl6]2− is 0.99 and 1.13 mmol/g, correspondingly. The respective adsorption constants KL = 6.8 and 10 × 105 l/mol prove the high affinity of the adsorbates to the QAS-modified surface. Platinum metal nanoparticles supported on the surface of the silica gel were prepared by reducing the adsorbed platinum (II, IV) complexes. Such nanoparticles functioning at the moderate temperature regime have demonstrated a reasonable catalytic activity for the hydrogen and oxygen recombination, and an excellent stability over 35 cycles of the reaction.

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