Phase separation in aqueous mixtures of hydrophobically modified cellulose derivatives with their nonmodified analogues

2001 ◽  
Vol 279 (4) ◽  
pp. 340-347 ◽  
Author(s):  
M. Tsianou ◽  
K. Thuresson ◽  
L. Piculell
Keyword(s):  
Phase Separation ◽  
Cellulose Derivatives ◽  
Aqueous Mixtures ◽  
Hydrophobically Modified ◽  
Modified Cellulose

Influence of Polymer Charge, Temperature, and Surfactants on Surface Sizing of Liner and Greaseproof Paper With Hydrophobically Modified Starch

TAPPI Journal ◽  
2009 ◽  
Vol 8 (2) ◽  
pp. 33-38 ◽  
Author(s):  
ANNA JONHED ◽  
LARS JÄRNSTRÖM
Keyword(s):  
Phase Separation ◽  
Contact Angles ◽  
Low Ph ◽  
Hydrophobically Modified ◽  
Paper Sizing ◽  
Surface Sizing ◽  
Separation Temperature ◽  
Hydrophobic Nature ◽  
Sizing Agents ◽  
Charge Temperature

The aim of this study was to investigate the properties of hydrophobically modified (HM) quaterna-ry ammonium starch ethers for paper sizing. These starches possess temperature-responsive properties; that is, gelation or phase separation occurs at a certain temperature upon cooling. This insolubility of the HM starches in water at room temperature improved their performance as sizing agents. The contact angles for water on sized liner were substantially larger than on unsized liner. When the application temperature was well above the critical phase-separation temperature, larger contact angles were obtained for liner independently of pH compared with those at the lower application temperature. Cobb60 values for liner decreased upon surface sizing, with a low pH and high application temperature giving lower water penetration. Contact angles on greaseproof paper decreased upon sur-face sizing as compared to unsized greaseproof paper, independently of pH and temperature. Greaseproof paper showed no great difference between unsized substrates and substrates sized with HM starch at different pH. This is probably due to the already hydrophobic nature of greaseproof paper. However, the Cobb60 values increased at low pH and low application temperature. Surfactants were added to investigate how they affect the sized surface. Addition of surfactant reduces the contact angles, in spite of indications of complex formation.

scholarly journals Skin and bubble formation in films made of methyl nanocellulose, hydrophobically modified ethyl(hydroxyethyl)cellulose and microfibrillated cellulose

Cellulose ◽  
2020 ◽  
Author(s):  
Johanna Lyytikäinen ◽  
Maria Morits ◽  
Monika Österberg ◽  
Isto Heiskanen ◽  
Kaj Backfolk
Keyword(s):  
Methyl Cellulose ◽  
Microfibrillated Cellulose ◽  
Hydroxyethyl Cellulose ◽  
Effect Of Temperature ◽  
Cellulose Derivatives ◽  
Air Bubbles ◽  
Oxygen Transmission Rate ◽  
Hydrophobically Modified ◽  
Film Forming ◽  
Ethyl Hydroxyethyl Cellulose

AbstractThe use of nanomaterials and polymers from renewable resources is important in the search for sustainable alternatives to plastic-based packaging materials and films. In this work, self-supporting thin films prepared from derivatized and non-derivatized nanocellulose and cellulose derivatives were studied. The effect of drying temperature on the film-forming behavior of compositions comprising hydrophobically modified ethyl(hydroxyethyl)cellulose (EHEC), native microfibrillated cellulose (MFC) and nanocellulose made from methyl cellulose was determined. The interaction between the components was assessed from viscosity measurements made at different temperatures, the result being linked to a thermal-dependent association during liquid evaporation, and the subsequent barrier and film-forming properties. The effect of temperature on suspensions was clearly different between the materials, confirming that there were differences in interaction and association between EHEC–MFC and methyl nanocellulose–MFC compositions. The amphiphilic EHEC affected both the suspension homogeneity and the film properties. Air bubbles were formed under certain conditions and composition particularly in MFC films, dependent on the drying procedure. The presence of air bubbles did not affect the oxygen transmission rate or the oil and grease resistance. An increasing amount of MFC improved the oxygen barrier properties of the films.

Dispersed Lipid Liquid Crystalline Phases Stabilized by a Hydrophobically Modified Cellulose

Langmuir ◽  
2007 ◽  
Vol 23 (5) ◽  
pp. 2768-2777 ◽  
Author(s):  
Mats Almgren ◽  
Johanna Borné ◽  
Eloi Feitosa ◽  
Ali Khan ◽  
Björn Lindman
Keyword(s):  
Liquid Crystalline ◽  
Crystalline Phases ◽  
Hydrophobically Modified ◽  
Liquid Crystalline Phases ◽  
Modified Cellulose

Unusual liquid–liquid phase transition in aqueous mixtures of a well-known dendrimer

2015 ◽  
Vol 17 (43) ◽  
pp. 28818-28829 ◽  
Author(s):  
Viviana C. P. da Costa ◽  
Onofrio Annunziata
Keyword(s):  
Phase Transition ◽  
Phase Separation ◽  
Liquid Phase ◽  
Aqueous Solutions ◽  
Salt Concentration ◽  
High Salt Concentration ◽  
Aqueous Mixtures ◽  
Liquid Phase Transition ◽  
Low Salt ◽  
Liquid Liquid Phase Separation

Salt induces liquid–liquid phase separation (LLPS) of the aqueous solutions of a dendrimer. LLPS occurs by cooling at low salt concentration and by heating at high salt concentration.

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