Search results for "Polymer gels"

showing 2 items of 2 documents

Guar gum/borax hydrogel: Rheological, low field NMR and release characterizations

2013

Guar gum (GG) and Guar gum/borax (GGb) hydrogels are studied by means of rheology, Low Field Nuclear Magnetic Resonance (LF NMR) and model drug release tests. These three approaches are used to estimate the mesh size (ζ) of the polymeric network. A comparison with similar Scleroglucan systems is carried out. In the case of GGb, the rheological and Low Field NMR estimations of ζ lead to comparable results, while the drug release approach seems to underestimate ζ. Such discrepancy is attributed to the viscous effect of some polymeric chains that, although bound to the network to one end, can freely fluctuate among meshes. The viscous drag exerted by these chains slows down drug…

Low field NMRMaterials sciencePolymers and PlasticsField (physics)General Chemical EngineeringDiffusionTransport processeslcsh:Chemical technologyPolymer Gels; Rheology; Low Field NMR; Transport processes; Mesh-sizechemistry.chemical_compoundRheologylcsh:TA401-492Materials ChemistryPolymer Gellcsh:TP1-1185Physical and Theoretical ChemistryComposite materialTransport processeGuar gumBoraxPolymer gelsOrganic ChemistryMesh-sizeLow field nuclear magnetic resonanceLow Field NMRlow field nmr; mesh-size; polymer gels; rheology; transport processesChemical engineeringchemistrySettore CHIM/09 - Farmaceutico Tecnologico ApplicativoSelf-healing hydrogelsViscous effectlcsh:Materials of engineering and construction. Mechanics of materialsRheologyExpress Polymer Letters
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Multivalent N-donor ligands for the construction of coordination polymers and coordination polymer gels

2018

This work describes the synthesis and characterisation of several multivalent N-donor ligands and their coordination compounds and the use of these ligands in the construction of coordination polymers and coordination polymer gels. The project can be divided into two parts. The first part of the research is focused on the coordination chemistry of ring-substituted biimidazoles in acidic media. The dependence of the formation of ion pairs and zwitterionic, especially zinc and copper containing coordination compounds on the pH of the reaction medium and ring-substituents of the ligand were examined. The second part of the study deals with the preparation of Ag, Zn and Cu coordination polymers…

geelitin situsemirigid N-donorsself-assemblykompleksiyhdisteetliganditioniccoordination polymerszwitterionicpolymeeritcoordination polymer gelsröntgenkristallografiakahtaisionitX-ray crystallography
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