Interplay of colloidal stability of cellulose nanocrystals and their dispersibility in cellulose acetate butyrate matrix

Blachechen, Leandro Schafranski; Mesquita, João Paulo de; Paula, Everton Luiz de; Pereira, Fabiano Vargas; Petri, Denise Freitas Siqueira

doi:10.1007/s10570-013-9881-y

Cited by 19 publications

(15 citation statements)

References 39 publications

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“…Figure 3 shows that the mean E values increased with the increase of TiO 2 content in the cryogels up to 10%, where the maximum E value achieved 100 ± 7 kPa. Similar behavior was observed for TiO 2 in epoxy composites [36] and cellulose nanocrystals in cellulose acetate butyrate composites [37]. A possible explanation for this effect is that for TiO 2 contents larger than 10%, the dispersion of the filler in the matrix is no longer effective, reducing the compressive strength.…”

Section: Characterization Of Composite Cryogelssupporting

confidence: 66%

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Recyclable Xanthan/TiO₂ Composite Cryogels towards the Photodegradation of Cr(VI) Ions and Methylene Blue Dye

Toledo

Marques

Petri

2019

International Journal of Polymer Science

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Composite cryogels were prepared from xanthan gum (XG) precursor gels at 20 g L-1 containing TiO2 load at 5, 10, and 20 wt% and citric acid, as crosslinker. The effect of the pH over precursor gel on the properties of the resulting cryogels was evaluated. The characterization of the XG/TiO2 cryogels comprised compression tests, swelling degree (SD) determination, Fourier transform infrared vibrational spectroscopy in the attenuated total reflectance mode (FTIR-ATR), scanning electron microscopy (SEM), and X-ray microtomography (CT) analyses. The largest compressive modulus (E) was observed for XG/TiO2 10% cryogels prepared at pH 4.0, which amounted to 100±7 kPa, whereas the E value determined for bare XG cryogels was 29±3 kPa. XG/TiO2 10% cryogels presented larger pores and thicker walls than bare XG cryogels, as evidenced by SEM and CT analyses. FTIR-ATR spectra evidenced the ester bonds stemming from the esterification among carboxylic acid groups and/or XG hydroxyl groups. XG/TiO2 10% cryogels presented SD of (61±2) gwater/gcryogel, long-term stability in water, and outstanding photocatalytic properties in the presence of Cr(VI) ions and methylene blue (MB). The photocatalytic processes for the reduction of Cr(VI) to Cr(III) and for the photobleaching of MB fitted the first-order kinetic model, yielding rate constants of 0.019 varying min-1 and 0.0096 min-1, respectively. For both processes, the XG/TiO2 10% cryogels could be recycled five times without losing shape or efficiency.

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Section: Characterization Of Composite Cryogelssupporting

confidence: 66%

“…In general, for cellular materials, the E values are expected to increase if the ρ app increase [38]. Thus, if the inorganic particles are well distributed in the polymeric matrix, increasing the composite density, the improvement of mechanical properties is expected [37].…”

Section: Characterization Of Composite Cryogelsmentioning

confidence: 99%

Recyclable Xanthan/TiO₂ Composite Cryogels towards the Photodegradation of Cr(VI) Ions and Methylene Blue Dye

Toledo

Marques

Petri

2019

International Journal of Polymer Science

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“…The compressive moduli of cryogels of xanthan and chitosan increased from 36 to 58 kPa due to the incorporation of 10% of CNC . The increase of ≈25% in the tensile modulus of cellulose acetate butyrate (CAB) films with sulfated CNC in comparison to neat CAB films was also achieved by the CNC content as low as ≈5%; higher CNC contents did not lead to better mechanical performance . The CNC high Young's modulus (from 50 to 100 GPa), small dimension, and large surface area favor the achievement of significant improvement in the mechanical properties by incorporating small amounts (1–10%) in the composites .…”

Section: Resultsmentioning

confidence: 99%

“…The amount of CNC was 5 or 15 wt% in order to evaluate the effects of CNC content in the mechanical behavior of the resulting cryogels. One should notice that amounts of CNC much higher than 5% seldom improve the mechanical properties of composites and high amounts of CNC might cause filler aggregation . Thus, the samples were coded with respect to the CNC type and concentration as HPMC (0% CNC), HPMC‐CNC‐SO 4 5% (5% CNC‐SO 4 ), HPMC‐CNC‐SO 4 15% (15% CNC‐SO 4 ), HPMC‐CNC 5% (5% CNC), and HPMC‐CNC 15% (15% CNC).…”

Section: Methodsmentioning

confidence: 99%

Cellulose Based Cryogels as Adsorbents for Organic Pollutants

Toledo

Martins

Pirich

et al. 2019

Macromolecular Symposia

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Cryogels of hydroxypropyl methylcellulose (HPMC) and bacterial cellulose nanocrystals (CNC) were prepared with 0, 5, or 15 wt% contents of CNC. Two types of CNC were used, namely, CNC‐SO4 and CNC, with ζ‐potential values of − (46 ± 1) mV and − (5 ± 1) mV, respectively. Regardless the CNC type or content, all cryogels presented similar density, capillarity constant, contact angle, swelling rate values, and morphology. However, the addition of only 5% of CNC‐SO4 to HPMC cryogels increased the compressive modulus from (120 ± 15) kPa to (150 ± 19) kPa. The cryogels were tested as adsorbents for 17α‐ethinyl estradiol (EE) and methylene blue (MB). In the dilute range, the pollutants removal efficiency of reinforced cryogels was considerably larger than that of neat cryogels. In the more concentrated range, all adsorbents presented similar efficiency. The adsorption isotherms of EE and MB onto cryogels fitted with sigmoidal and Freundlich adsorption models, indicating higher affinity for aerogels with 5% CNC‐SO4. Cryogels could be recycled 10 and 5 times, respectively, for MB and EE adsorption/desorption under flow without losing efficiency, disclosing their potential for preconcentration of pollutants, and environmental remediation.

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“…At the same time, the fibers release the rigid crystalline regions which form needle‐shaped nanoparticles of cellulose nanocrystals (CNCs). Because of the fully stretched cellulose chains in perfect crystals, CNCs own outstanding mechanical performances with high Young's modulus (150 GPa) and strength (7 GPa), therefore, CNCs had been frequently chosen as reinforcing material for various polymers such as polylactide, cellulose acetate butyrate, poly(butylene succinate), poly(vinyl alcohol), poly(3‐hydroxybutyrate‐ co ‐3‐hydroxyvalerate), polyurethane, and alginate …”

Section: Introductionmentioning

confidence: 99%

Nanocomposites of poly(propylene carbonate) reinforced with cellulose nanocrystals via sol‐gel process

Wang

Xia

Wei

et al. 2014

J of Applied Polymer Sci

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Cellulose nanocrystals (CNCs) organogels were first produced from aqueous dispersion through solvent exchange of CNCs to acetone via a simple sol-gel process. After mixing the organogels with poly(propylene carbonate) (PPC) in dimethylformamide followed by solution casting, green nanocomposites were obtained with CNCs well dispersed in PPC polymer matrix which was confirmed by scanning electron microscopy observations. Differential scanning calorimeter analysis revealed that glass transition temperature of the nanocomposites was slightly increased from 34.0 to 37.4 C. Tensile tests indicated that both yield strength and Young's modulus of CNCs/PPC nanocomposites were doubled by adding 10 wt % CNCs. However, poor thermal stability of PPC occurred after incorporating with CNCs due to the thermo-sensitive sulfate groups located on the surface of CNCs. Furthermore, PPC became more hydrophilic because of the inclusion of CNCs according to the water contact angle measurement. The enhanced mechanical and hydrophilic properties, coupled with the inherent superior biocompatibility and degradability, offered CNCs/PPC composites potential application in biomedical fields.

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Interplay of colloidal stability of cellulose nanocrystals and their dispersibility in cellulose acetate butyrate matrix

Cited by 19 publications

References 39 publications

Recyclable Xanthan/TiO₂ Composite Cryogels towards the Photodegradation of Cr(VI) Ions and Methylene Blue Dye

Recyclable Xanthan/TiO₂ Composite Cryogels towards the Photodegradation of Cr(VI) Ions and Methylene Blue Dye

Cellulose Based Cryogels as Adsorbents for Organic Pollutants

Nanocomposites of poly(propylene carbonate) reinforced with cellulose nanocrystals via sol‐gel process

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Interplay of colloidal stability of cellulose nanocrystals and their dispersibility in cellulose acetate butyrate matrix

Cited by 19 publications

References 39 publications

Recyclable Xanthan/TiO2 Composite Cryogels towards the Photodegradation of Cr(VI) Ions and Methylene Blue Dye

Recyclable Xanthan/TiO2 Composite Cryogels towards the Photodegradation of Cr(VI) Ions and Methylene Blue Dye

Cellulose Based Cryogels as Adsorbents for Organic Pollutants

Nanocomposites of poly(propylene carbonate) reinforced with cellulose nanocrystals via sol‐gel process

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Product

Resources

About

Recyclable Xanthan/TiO₂ Composite Cryogels towards the Photodegradation of Cr(VI) Ions and Methylene Blue Dye

Recyclable Xanthan/TiO₂ Composite Cryogels towards the Photodegradation of Cr(VI) Ions and Methylene Blue Dye