0000000000297285

AUTHOR

Gina-gabriela Bumbu

showing 5 related works from this author

Investigation of the Interpolymer Complex between Hydroxypropyl Cellulose and Maleic Acid-Styrene Copolymer, 1

2004

The hydrogen bonding-interpolymer association of hydroxypropyl cellulose (HPC) with maleic acid-styrene (MAc-S) copolymer has been investigated in dilute aqueous solution by viscometry, turbidimetry and potentiometry. At a mixing ration between MAc-S and HPC of 10:90, the solution exhibits a phase separation upon heating, while for other mixing ration no phase separation could be detected. The stability of the interpolymer complex (IPC) increases as the temperatures rises. The stoichiometry of the IPC, in mole units, was estimated as being MAc-S:HPC=5:2. The thermodynamic functions (enthalpy and entropy) of the complexation process have been determined.

Aqueous solutionPolymers and PlasticsMaleic acidChemistryHydroxypropyl celluloseOrganic ChemistryEnthalpyCondensed Matter PhysicsPolyelectrolyteStyrenechemistry.chemical_compoundPolymer chemistryMaterials ChemistryCopolymerTurbidimetryPhysical and Theoretical ChemistryMacromolecular Chemistry and Physics
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Cover Picture: Macromol. Biosci. 10/2005

2005

BiomaterialsGeographyPolymers and PlasticsMaterials ChemistryBioengineeringCover (algebra)Physical geographyBiotechnologyMacromolecular Bioscience
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Interpolymer complex between hydroxypropyl cellulose and maleic acid-styrene copolymer: phase behavior of semi-dilute solutions.

2005

Summary: The phase behavior of a water/hydroxypropyl cellulose/maleic acid–styrene copolymer (H2O/HPC/MAc-S) system was investigated in the semi-dilute range by turbidimetry, rheology, and optical microscopy. The two polymers under investigation form interpolymer complexes via hydrogen bonding. In the case of a total polymer concentration of cpol = 5 mg · mL−1 a second phase segregates upon heating the homogeneous ternary system. By applying a constant shear rate ( = 50 s−1) the phase separation temperature of the system is 10–15 °C lower than for an unsheared one. For cpol = 10 mg · mL−1 phase separation has already occurred at room temperature when the two binary polymer solutions are mix…

Materials sciencePolymers and PlasticsMaleic acidBioengineeringStyreneBiomaterialschemistry.chemical_compoundNephelometry and TurbidimetryPhase (matter)Polymer chemistrySpectroscopy Fourier Transform InfraredMaterials ChemistryCopolymerCellulosechemistry.chemical_classificationCloud pointTernary numeral systemMolecular StructureHydroxypropyl celluloseMaleatesTemperatureWaterPolymerSolutionschemistryChemical engineeringPolystyrenesRheologyBiotechnologyMacromolecular bioscience
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From Spherical Mesopores to Worm-Shaped Mesopores : Morphology Transition in Titania–Polystyrene-b-poly(ethylene oxide) Composite Films with Increasi…

2013

A morphology transition from spherical mesopores to worm-shaped mesopores within titania block copolymer composite thin films has been observed by varying the sol–gel reaction time from 40 min to 48 h in the four-component templating system of polystyrene-$\mathit{b}$-poly(ethylene oxide) (PS-$\mathit{b}$-PEO), 1,4-dioxane, concentrated HCl, and titanium tetraisopropoxide (TTIP) with a PS-$\mathit{b}$-PEO mass concentration of 0.25 wt.-%. The impact of the sol–gel reaction time on the local structure, long-range lateral structure, and vertical structure of the as-prepared, calcined, and UV-degraded thin films as well as the structural changes in solution have been systematically investigate…

ChemieNanotechnologyMicellelaw.inventionInorganic ChemistryX-ray reflectivitychemistry.chemical_compoundDynamic light scatteringchemistryChemical engineeringlawddc:540Grazing-incidence small-angle scatteringCalcinationPolystyreneMesoporous materialSol-gel
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Morphology evolution in mesoporous titania block copolymer composite films with increasing Sol-Gel reaction time

2013

A morphology evolution of thin films of titania from spherical mesopores to worm-shaped mesopores was realized by simply varying the sol–gel reaction time from 46 min to 25 h in the quadruple system consisting of polystyrene–block-poly(ethylene oxide) (PS–b-PEO), 1,4-dioxane, concentrated HCl, and titanium tetraisopropoxide (TTIP). Imaging techniques including scanning electron microscopy (SEM) and atomic force microscopy (AFM) were applied to investigate the local structure change of the as-prepared, calcined, and UV-degraded composite films. Grazing incidence small angle X-ray scattering (GISAXS) experiments prove that the structure change in local areas is representative of that over the…

Inorganic ChemistryX-ray reflectivityChemical engineeringDynamic light scatteringScanning electron microscopeChemistryComposite numberCopolymerChemieGrazing-incidence small-angle scatteringNanotechnologyMesoporous materialSol-gel
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