Aggregation and network formation of aqueous methylcellulose and hydroxypropylmethylcellulose solutions

Bodvik, Rasmus; Dédinaité, Andra; Karlson, Leif; Bergström, Magnus; Bäverbäck, Petra; Pedersen, Jan Skov; Edwards, Katarina; Karlsson, Göran; Varga, Imre; Claesson, Per M.

doi:10.1016/j.colsurfa.2009.09.040

Cited by 143 publications

(195 citation statements)

References 41 publications

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“…A similar effect was observed in other silicate systems, namely in aqueous solutions of lithium silicates [4] and sodiumtetramminezinc silicate [5]), as well as in several non-silicate organic systems. The latter include aqueous solutions of methylcellulose [6,7], of hydroxypropyl methylcellulose [6,8], of some block copolymers based on polyalkylene glycols, N-substituted polyacrylamides, polyphosphazenes, etc. [9,10].…”

Section: Literature Review and Problem Statementmentioning

confidence: 99%

The rheological anomaly in water-silicate systems: a possible thermodynamic explanation

Maliavski

Zhuravlova²,

Denysiuk

2017

EEJET

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Section: Literature Review and Problem Statementmentioning

confidence: 99%

The rheological anomaly in water-silicate systems: a possible thermodynamic explanation

Maliavski

Zhuravlova²,

Denysiuk

2017

EEJET

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“…For a given semicrystalline polymer, such as cellulose, the chains are more in the regular, arrangement and it is rather difficult to unfold the well-packed chains into a disordered state in solution (Lindman et al 2010;Medronho and Lindman 2014). Over decades the hydrogen bonds network in cellulose has been claimed as the reason of the crystalline structure of cellulose and the limitations in cellulose dissolution (Bodvik et al 2010;Zhang et al 2002), while the amphiphilic nature of cellulose has probably been underestimated (Medronho et al 2012. Thus, when developing efficient solvents for cellulose dissolution, not only the intermolecular hydrogen bonds need to be overcome, but also the hydrophobic chain interactions have to be minimized (Glasser et al 2012;Medronho et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Spherical nanocomposite particles prepared from mixed cellulose–chitosan solutions

et al. 2016

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Novel cellulose-chitosan nanocomposite particles with spherical shape were successfully prepared via mixing of aqueous biopolymer solutions in three different ways. Macroparticles with diameters in the millimeter range were produced by dripping cellulose dissolved in cold LiOH/urea into acidic chitosan solutions, inducing instant co-regeneration of the biopolymers. Two types of microspheres, chemically crosslinked and non-crosslinked, were prepared by first mixing cellulose and chitosan solutions obtained from freeze thawing in LiOH/KOH/urea. Thereafter epichlorohydrin was applied as crosslinking agent for one of the samples, followed by water-inoil (W/O) emulsification, heat induced sol-gel transition, solvent exchange, washing and freeze-drying. Characterization by X-ray photoelectron spectroscopy, total elemental analysis, and Fourier transform infrared spectroscopy confirmed the prepared particles as being true cellulose-chitosan nanocomposites with different distribution of chitosan from the surface to the core of the particles depending on the preparation method. Field emission scanning electron microscopy and laser diffraction was performed to study the morphology and size distribution of the prepared particles. The morphology was found to vary due to different preparation routes, revealing a core shell structure for macroparticles prepared by dripping, and homogenous nanoporous structure for the microspheres. The non-crosslinked microparticles exhibited a somewhat denser structure than the crosslinked ones, which indicated that crosslinking restricts packing of the chains before and under regeneration. From the obtained volume-weighted size distributions it was found that the crosslinked microspheres had the highest median diameter. The results demonstrate that not only the mixing ratio and distribution of the two biopolymers, but also the morphology and nanocomposite particle diameters are tunable by choosing between the different routes of preparation.

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“…Interestingly, the development of moduli in aqueous MC is dramatically different to that in aqueous HPMC during the sol-gel transition. [29][30][31][32] For HPMC solutions, as temperature is raised, a sudden drop in the storage modulus is observed followed by an increase as gelation occurs. In contrast for MC solutions no sharp drop appears, the solutions merely thicken as temperature is increased.…”

Section: Introductionmentioning

confidence: 99%

Interplay between Gelation and Phase Separation in Aqueous Solutions of Methylcellulose and Hydroxypropylmethylcellulose

et al. 2012

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Thermally-induced gelation in aqueous solutions of methylcellulose (MC) and hydroxypropyl methylcellulose (HPMC) has been studied by rheological, optical microscopy and turbidimetry measurements. The structural and mechanical properties of these hydrogels are dominated by the interplay between phase separation and gelation. In MC solutions, phase separation takes place almost simultaneously with gelation. An increase in the storage modulus is coupled to the appearance of a bicontinuous structure upon heating. However, a thermal gap exists between phase separation and gelation in the case of HPMC solutions. The storage modulus shows a dramatic decrease during phase 2 separation, and then rises in the subsequent gelation. A macroporous structure forms in the gels via "viscoelastic phase separation" linked to "double phase separation".

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Aggregation and network formation of aqueous methylcellulose and hydroxypropylmethylcellulose solutions

Cited by 143 publications

References 41 publications

The rheological anomaly in water-silicate systems: a possible thermodynamic explanation

The rheological anomaly in water-silicate systems: a possible thermodynamic explanation

Spherical nanocomposite particles prepared from mixed cellulose–chitosan solutions

Interplay between Gelation and Phase Separation in Aqueous Solutions of Methylcellulose and Hydroxypropylmethylcellulose

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