Thermal behavior of water in the selected starch- and cellulose-based polymeric hydrogels

Faroongsarng, Damrongsak; Sukonrat, Patchara

doi:10.1016/j.ijpharm.2007.10.022

Cited by 47 publications

(30 citation statements)

References 24 publications

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“…In the whole range of W c , the T max were positive and the cluster gently rose from 0°C not exceeding 3°C (DT max & 3°C). This corresponds very well with the observations of Faroongsarng and Sukonrat [27], who showed that the depression of melting temperature is not only attributed to water-polymer interactions, but water embedded in the pores and/or cavities of the matrix as well.…”

Section: Resultssupporting

confidence: 92%

The DSC approach to study non-freezing water contents of hydrated hydroxypropylcellulose (HPC)

Talik

Hubicka

2017

J Therm Anal Calorim

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The research consisted of investigation of non-freezable bound water (NFW) contents of raw hydroxypropylcellulose (HPC) Klucel Ò Pharm HF, MF, and LF by differential scanning calorimetry. Polymers (HF, MF and LF) used in the research differed significantly in their molecular mass and viscosity. Mixtures of HPC and low soluble salicylic acid or highly soluble sodium salicylate were used to examine the effect of counter-ions presence and drug solubility on NFW contents. The dependencies of determined enthalpies of melting (DH) and respective contents of water W c (water fraction in the dry mass of HPC or HPC mixture) DH = f(W c ) were linear. The sought values of non-freezing water were calculated (by extrapolation) as the concentration at which DH = 0. It was found that the viscosity and molecular mass of the raw HPCs did not affect the contents of non-freezing water, which ranged between 0.54 and 0.51 g g -1 for all types LF, MF, HF. Poorly soluble salicylic acid (SA) reduced the non-freezing water content to 0.19-0.17 g g -1 . On the other hand, matrices composed of highly soluble sodium salicylate (NaSA) showed variable decrease of NFW content-0.44 g g -1 for HF and 0.54-0.51 g g -1 for LF and MF. It was also found that the maximum temperature T max of melting was strongly influenced by the solubility of the drug. Highly soluble NaSA shifted T max toward the lower negative values, while SA toward the higher positive values. Assessing NFW contents in hydrated HPC matrices may contribute to a better understanding of the drug release and dissolution mechanisms of tablet formulations.

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Section: Resultssupporting

confidence: 92%

The DSC approach to study non-freezing water contents of hydrated hydroxypropylcellulose (HPC)

Talik

Hubicka

2017

J Therm Anal Calorim

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“…Water absorbency values generally in the range of 40 to 1400 g/g have been reported in such studies, with the highest value reported by Pourjavadi et al (2008). Copolymers incorporating CMC have also been prepared with polyvinyl alcohol (El Salmawi 2007), hydroxyethyl cellulose (Oppermann 1995;Lionetto et al 2003;Sannino and Nicolais 2005;Demitri et al 2008;Dai and Kadla 2009), and with hydroxypropylethyl cellulose (Faroongwarng and Sukonrat 2008).…”

Section: Copolymers Of Cmc By Reaction With Monomersmentioning

confidence: 96%

“…In other words, its properties can be expected to differ from those of bulk water in terms of such behaviors as freezing tendencies and temperatures. Accordingly, Faroongwarng and Sukonrat (2008) observed that the freezing point of water was depressed within hydrogels. Gelin et al (2007) estimated that only about 10% of water present in a typical hydrogel acts like bulk water.…”

Section: Hydration and Hydrogen Bonding Effectsmentioning

confidence: 99%

Enhanced Absorbent Products Incorporating Cellulose and Its Derivatives: A Review

Hubbe¹,

Ayoub²,

Daystar³

et al. 2013

BioResources

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Cellulose and some cellulose derivatives can play vital roles in the enhancement of the performance of absorbent products. Cellulose itself, in the form of cellulosic fibers or nano-fibers, can provide structure, bulk, water-holding capacity, and channeling of fluids over a wide dimensional range. Likewise, cellulose derivatives such as carboxymethylcellulose (CMC) have been widely studied as components in superabsorbent polymer (SAP) formulations. The present review focuses on strategies and mechanisms in which inclusion of cellulose -in its various formscan enhance either the capacity or the rate of aqueous fluid absorption in various potential applications.

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“…Thermodynamically, this phenomenon governs by two different processes, i.e., either polymer solution or water confinement within reticulated structure of cellulose. On one hand, it has been demonstrated that the depressed melting temperature of a fraction of bound water in hydrogels of some cellulose derivatives may be due to polymer solution (6). On the other hand, previous study in microcrystalline cellulose-water interaction suggested that bound water may reside in small pores created during wet granulation resulting in lowering its phase transition temperature (7).…”

Section: Introductionmentioning

confidence: 99%

“…In addition, the reticulated structure characterization of BC film becomes important due to the fact that some agents such as silver nanoparticles (4) have been incorporated in BC to have the wound dressing with antimicrobial activity. Thermal behavior of water may characterize the reticulated structure of BC membranes as the interfacial tension related to surface of curvature of water within pores could develop and then depress the water confinement phase transition (6). The aim of this study is to examine the thermal behavior of freezable bound/confined water within reticulated structure of BC films by sub-ambient differential scanning calorimetry with an approach using thermoporosimetry.…”

Section: Introductionmentioning

confidence: 99%

Behavior of Freezable Bound Water in the Bacterial Cellulose Produced by Acetobacter xylinum: An Approach Using Thermoporosimetry

2008

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Abstract. The aim of the study is to examine thermal behavior of water within reticulated structure of bacterial cellulose (BC) films by sub-ambient differential scanning calorimetry (DSC). BC films with different carbon source, either manitol (BC (a)) or glycerol (BC (b)), were produced by Acetobacter xylinum using Hestrin and Shramm culture medium under static condition at 30±0.2°C for 3 days. BC samples were characterized by electron scanning microscopy and X-ray diffraction spectroscopy. The pore analysis was done by B.H.J. nitrogen adsorption. The pre-treated with 100% relative humidity, at 30.0±0.2°C for 7 days samples were subjected to a between 25 and −150°C-cooling-heating cycle of DSC at 5.00°C/min rate. The pre-treated samples were also hydrated by adding 1 μl of water and thermally run with identical conditions. It is observed that cellulose fibrils of BC (a) were thinner and reticulated to form slightly smaller porosity than those of BC (b). They exhibited slightly but non-significantly different crystalline features. The freezable bound water behaved as a water confinement within pores rather than a solvent of polymer which is possible to use thermoporosimetry based on Gibb-Thomson equation to approach pore structure of BC. In comparison with nitrogen adsorption, it was found that thermoporosimetry underestimated the BC porosity, i.e., the mean diameters of 23.0 nm vs. 27.8 nm and 27.9 nm vs. 33.9 nm for BC (a) and BC (b), respectively, by thermoporosimetry vs. B.H.J. nitrogen adsorption. It may be due to large non-freezable water fraction interacting with cellulose, and the validity of pore range based on thermodynamic assumptions of Gibb-Thomson theory.

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Thermal behavior of water in the selected starch- and cellulose-based polymeric hydrogels

Cited by 47 publications

References 24 publications

The DSC approach to study non-freezing water contents of hydrated hydroxypropylcellulose (HPC)

The DSC approach to study non-freezing water contents of hydrated hydroxypropylcellulose (HPC)

Enhanced Absorbent Products Incorporating Cellulose and Its Derivatives: A Review

Behavior of Freezable Bound Water in the Bacterial Cellulose Produced by Acetobacter xylinum: An Approach Using Thermoporosimetry

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