Cross-linked pectic acid. The effect of cross-linking on cation exchange, binding of endopolygalacturonase and biodegradability

1976 ◽  
Vol 41 (7) ◽  
pp. 1879-1893 ◽  
Author(s):  
R. Kohn ◽  
Ľ. Rexová-Benková ◽  
O. Luknár ◽  
Ľ. Kuniak
Keyword(s):  
Cation Exchange ◽  
Cross Linking ◽  
Pectic Acid

Comparison of Cation Exchange in Ganophyllite and [Na + Al]-Substituted Tobermorite: Crystal-Chemical Implications

1988 ◽  
Vol 52 (366) ◽  
pp. 371-375 ◽  
Author(s):  
Sridhar Komarneni ◽  
Stephen Guggenheim
Keyword(s):  
Cation Exchange ◽  
Exchangeable Cations ◽  
Cross Linking ◽  
Crystal Chemical ◽  
Layer Silicates ◽  
Residual Charge ◽  
Interlayer Region ◽  
Exchange Properties ◽  
Charge Configuration

AbstractGanophyllite and [Na+ + Al3+]-substituted tobermorite exhibited similar cation exchange properties and, in particular, selective cesium exchange. [Na+ + Al3+]-substituted tobermorite and ganophyllite showed a selective Cs exchange of 10.77 and 8.71 meq/100 g from 0.02N NaCl and of 11.08 and 9.04 meq/100 g from 0.02N CaCl2, respectively. The [Na+ + Al3+]-substituted tobermorite is structurally similar to ganophyllite: both are roughly analogous to 2:1 layer silicates, both have cross-linking tetrahedra across the interlayer region, and both have exchangeable cations located in zeolite-like sites in the interlayer region. The similarities in cation exchange properties imply that the residual charge configuration of the analogue 2 : 1 layer must be approximately equivalent also.

CATION EXCHANGE IN ANHYDROUS ETHYLENEDIAMINE

1965 ◽  
Vol 43 (5) ◽  
pp. 1096-1101 ◽  
Author(s):  
Walter R. Heumann ◽  
Onil Dionne ◽  
Gilles Tremblay
Keyword(s):  
Aqueous Solutions ◽  
Cation Exchange ◽  
Alkali Metals ◽  
Cross Linking ◽  
Exchange Reactions ◽  
Degree Of Dissociation ◽  
Cation Exchangers ◽  
Low Degree ◽  
Acid Cation

The swelling of the strongly acid cation exchangers Dowex 50 W of various degrees of cross-linking is markedly less in ethylenediamine than in water. However, it is sufficient for exchange reactions to occur. In contrast with aqueous solutions, electrolytes dissolved in ethylenediamine cause the swelling to increase, which is attributed to the low degree of dissociation attainable in this solvent. This explanation is supported by the observation that in water slightly dissociated electrolytes also produce a slight increase in swelling. Exchange reactions were carried out successfully with the slightly cross-linked resin Dowex 50 W-X2. The bromide, ethoxide, aminoethoxide, and 2-aminoethylamide of lithium exchanged the latter cation with other alkali metals or tetrabutylammonium easily.

Preparation and characterization of Ca(II) cross-linking modified pectin microspheres for Pb(II) adsorption

2019 ◽  
Vol 79 (8) ◽  
pp. 1484-1493
Author(s):  
Fen Li ◽  
Zhao Xu ◽  
Xiaoyan Wen ◽  
Xiaoyong Li ◽  
Yanhong Bai ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Isotherm Models ◽  
Cross Linking ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Wastewater Purification ◽  
Adsorption Ability ◽  
Pectic Acid ◽  
Pseudo Second Order

Abstract A novel adsorbent, composed of cross-linked de-esterified pectin microspheres, was prepared via cross-linking with Ca(II) and modification by de-esterified pectin, low-methoxyl pectin (LMP) and pectic acid (PA). Fourier transform infrared (FTIR), energy dispersive spectrometry (EDS), scanning electron microscopy (SEM) and atomic absorption spectroscopy (AAS) were applied too, exhibiting a successful fabrication, good adsorption ability, and well-defined surface microstructure beneficial to Pb(II) adsorption. The adsorption ability of pectin microspheres (PMs), low-methoxyl pectin microspheres (LMPMs) and pectic acid microspheres (PAMs) for Pb(II) in aqueous solution were explored. The maximum adsorption capacity of PMs, LMPMs and PAMs was 127 mg·g−1, 292 mg·g−1 and 325 mg·g−1 at pH 5.0 respectively, indicating a great improvement of LMPMs and PAMs in the adsorption ability for Pb(II) compared with PMs. Furthermore, the adsorption mechanism was proposed. The experimental data were well fitted with pseudo-second-order kinetic and Langmuir isotherm models. Five-cycle reusability tests demonstrated that microspheres could be used repeatedly. All the results confirmed that LMPMs and PAMs, which presented outstanding adsorption capability and reusability, could be a good candidate for wastewater purification.

Selective Co(ii) removal from aqueous media by immobilizing silver nanoparticles within a polymer-matrix through a formaldehyde cross linking agent

RSC Advances ◽  
2015 ◽  
Vol 5 (30) ◽  
pp. 23340-23349 ◽  
Author(s):  
S. Siva ◽  
S. Sudharsan ◽  
R. Sayee Kannan
Keyword(s):  
Aqueous Solution ◽  
Silver Nanoparticles ◽  
Cation Exchange ◽  
Polymer Matrix ◽  
Cation Exchanger ◽  
Exchange Resin ◽  
Phenol Formaldehyde ◽  
Aqueous Media ◽  
Cation Exchange Resin ◽  
Cross Linking

A novel hybrid cation exchange resin was developed by encapsulating AgNPs within a macroporous phenol–formaldehyde cation exchanger for the removal of cobalt from aqueous solution.

Influence of Calcium Ions on the Plant Cell Surface: Membrane Fusions and Conformational Changes

1974 ◽  
Vol 32 ◽  
pp. 154-155
Author(s):  
D. James Morré ◽  
Charles E. Bracker ◽  
William J. VanDerWoude
Keyword(s):  
Cell Wall ◽  
Cell Surface ◽  
Conformational Changes ◽  
Calcium Ions ◽  
Surface Membrane ◽  
Carboxyl Groups ◽  
Cross Linking ◽  
Ultrastructural Evidence ◽  
Glycine Max L ◽  
Wall Extensibility

Calcium ions in the concentration range 5-100 mM inhibit auxin-induced cell elongation and wall extensibility of plant stems. Inhibition of wall extensibility requires that the tissue be living; growth inhibition cannot be explained on the basis of cross-linking of carboxyl groups of cell wall uronides by calcium ions. In this study, ultrastructural evidence was sought for an interaction of calcium ions with some component other than the wall at the cell surface of soybean (Glycine max (L.) Merr.) hypocotyls.

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