Surface properties of distinct nanofibrillated celluloses assessed by inverse gas chromatography

Gamelas, José A. F.; Pedrosa, Jorge; Lourenço, Ana F.; Ferreira, Paulo J.

doi:10.1016/j.colsurfa.2014.12.058

Cited by 21 publications

(22 citation statements)

References 31 publications

(46 reference statements)

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“…Consistent with the Lindman hypothesis, both samples are amphoteric (Lindman et al 2010) (Table S1), both powders feature higher dispersive surface energies than cotton (Kondor et al 2015) and lyocell fibers (Tze et al 2006) and are comparable to TEMPO-oxidized and genuine CNF (Peng et al 2013;Gamelas et al 2015).…”

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confidence: 65%

Surface properties and porosity of highly porous, nanostructured cellulose II particles

et al. 2016

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Recently, a new member of the nanocellulose family was introduced, a cellulose II gel consisting of nanostructured and spherical particles. In this study, we compared two different drying techniques to obtain highly porous powders from this gel with preserved meso-and macroporous nanostructure: first, freeze-drying after solvent exchange to tBuOH and second, supercritical drying of the respective EtOH alcogel. The approaches yielded aerogel powders with surface areas of 298 and 423 m 2 /g, respectively. Both powders are amphiphilic and possess energetically heterogeneous surfaces with dominating dispersive term of the surface energy in the range of 50-52 mJ/m 2 , as determined by a combination of physicochemical surface characterization techniques, such as iGC, BET and SEM. Despite the lower surface area, the cheaper and more widespread method, freeze-drying, yields a more polar and reactive cryogel.Keywords Nanocellulose Á Lyocell Á Inverse gas chromatography Á Thermoporosimetry Á Freezedrying Á Supercritical drying Abbreviations CNFCellulose nanofibrils FD Freeze-drying scCO 2 Supercritical CO 2 Electronic supplementary material The online version of this article

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confidence: 65%

Surface properties and porosity of highly porous, nanostructured cellulose II particles

et al. 2016

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“…For the unmodified xylan a decreasing trend of the γ s d value with temperature in the range of studied temperatures (40-55°C) was found (Fig. 4), as previously observed for related cellulosic materials [35,42]. For the CMX the variation of the γ s d value with temperature (in the same temperature range) was somewhat different: it decreased from 40 to 45°C and then reached a plateau (Fig.…”

Section: Surface Properties Assessed By Inverse Gas Chromatographysupporting

confidence: 59%

“…In the 1500-1700 cm −1 region, bands at 1600 cm −1 and ca. 1645 cm −1 (shoulder) from ionized glucuronic acid groups and sorbed water, respectively, were also observed [33][34][35]. For CMX (Fig.…”

Section: U N C O R R E C T E D P R O O Fmentioning

confidence: 83%

“…The γ s d (at 40°C, and at 35°C for HPX) varied in the following order: BX > CMX > HPX. The relatively high value of γ s d observed for unmodified xylan can be majorly related to a higher amount/accessibility of hydroxyl groups (which are able to establish dispersive interactions with the n-alkanes [35,40]) on the surface of this xylan. No previous studies of xylans surfaces by IGC were found in the literature; however, the γ s d value here obtained for beech xylan is in the same range of those reported for other polysaccharides such as cellulose and bleached pulps (40-50 mJ m −2 range) [22].…”

Section: Surface Properties Assessed By Inverse Gas Chromatographymentioning

confidence: 99%

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Surface properties of xylan and xylan derivatives measured by inverse gas chromatography

Sousa

Pedrosa

Ramos

et al. 2016

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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Xylan (the most common hemicellulose in wood and annual plants) and xylan derivatives have a very wide field of uses for which physico-chemical surface properties play an important role (e.g. in composites or barrier materials). In the present work, for the first time, inverse gas chromatography (at infinite dilution conditions) was used to assess the surface properties of xylan and xylan derivatives. Firstly, carboxymethyl xylan (CMX) and hydroxypropyl xylan (HPX) have been synthesized from commercial xylan (BX) and the presence of substituent groups confirmed by infrared spectroscopy and 1 H NMR. Then, the modified and original xylans were analysed for their dispersive component of the surface energy (γ s d ) and Lewis acid-base properties. It was found that carboxymethylation and hydroxypropylation decreased significantly the γ s d value of xylan: from 47.6 mJ m −2 in BX to 33.0 mJ m −2 and 23.5 mJ m −2 in CMX and HPX, respectively. As for the Lewis acid-base properties, HPX showed a perfectly amphoteric behaviour while the surfaces of unmodified xylan and CMX showed a prevalence of Lewis acidic character over the Lewis basic character, being, however, the surface of CMX less acidic than that of the original xylan. These results were interpreted in terms of the effect of the presence of the new substituent groups in the xylan backbone.

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“…No previous studies of the surface of this type of materials by IGC were found in the literature. However, the γ s d values are comparable with those of chitosan or alginate alone or of other polysaccharides, such as cellulose and hemicelluloses . For instance, a 80% deacetylated chitosan presented a γ s d value of 46 mJ·m −2 at 50°C and sodium alginate showed a γ s d value of 39 mJ·m −2 at 25°C.…”

Section: Resultsmentioning

confidence: 78%

Surface characterization of polysaccharide scaffolds by inverse gas chromatography regarding application in tissue engineering

Coimbra

Coelho

Gamelas

2019

Surface & Interface Analysis

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Scaffolds are of paramount importance in tissue engineering, providing support for cell attachment and allowing proliferation or differentiation, and production of extracellular matrix. Their surface properties are of major interest since in great part, they determine the biological response to the scaffold. In the present work, three chitosan‐based polyelectrolytes scaffolds, namely, 1:1 chitosan‐alginate (Chit‐Alg), chitosan‐pectin (Chit‐Pect), and chitosan‐carboxymethyl cellulose (Chit‐CMC), were studied with regard to their surface properties by inverse gas chromatography. The dispersive component of the surface energy, a measure of the ability of a material to establish Lifshitz Van der Waals interactions, was 47.8 mJ·m−2 for Chit‐Alg, 36.9 mJ·m−2 for Chit‐Pect, and 38.5 mJ·m−2 for Chit‐CMC (at 40°C). All the scaffolds surfaces had an amphoteric character, however, with an apparent prevalence of Lewis acidity over the Lewis basicity. These results have been interpreted in terms of the influence of the different substituent groups in the polysaccharides backbone. The porosities of the Chit‐Alg, Chit‐Pect, and Chit‐CMC scaffolds, assessed by mercury intrusion porosimetry, were found to be of 98%, 96%, and 84%, respectively.

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Surface properties of distinct nanofibrillated celluloses assessed by inverse gas chromatography

Cited by 21 publications

References 31 publications

Surface properties and porosity of highly porous, nanostructured cellulose II particles

Surface properties and porosity of highly porous, nanostructured cellulose II particles

Surface properties of xylan and xylan derivatives measured by inverse gas chromatography

Surface characterization of polysaccharide scaffolds by inverse gas chromatography regarding application in tissue engineering

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