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Biodegradable polycaprolactone-titania nanocomposites: preparation, characterization and antimicrobial properties.

Muñoz-Bonilla A, Cerrada ML, Fernández-García M, Kubacka A, Ferrer M, Fernández-García M - Int J Mol Sci (2013)

Bottom Line: TEM evaluation provides evidence of an excellent nanometric dispersion of the oxide component in the polymeric matrix, with aggregates having an average size well below 100 nm.Presence of these TiO2 nanoparticles induces a nucleant effect during polymer crystallization.The bactericidal behavior has been explained through the analysis of the material optical properties, with a key role played by the creation of new electronic states within the polymer-based nanocomposites.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), C/Juan de la Cierva 3, 28006 Madrid, Spain. sbonilla@ictp.csic.es.

ABSTRACT
Nanocomposites obtained from the incorporation of synthesized TiO2 nanoparticles (≈10 nm average primary particle size) in different amounts, ranging from 0.5 to 5 wt.%, into a biodegradable polycaprolactone matrix are achieved via a straightforward and commercial melting processing. The resulting nanocomposites have been structurally and thermally characterized by transmission electron microscopy (TEM), wide/small angle X-ray diffraction (WAXS/SAXS, respectively) and differential scanning calorimetry (DSC). TEM evaluation provides evidence of an excellent nanometric dispersion of the oxide component in the polymeric matrix, with aggregates having an average size well below 100 nm. Presence of these TiO2 nanoparticles induces a nucleant effect during polymer crystallization. Moreover, the antimicrobial activity of nanocomposites has been tested using both UV and visible light against Gram-negative Escherichia coli bacteria and Gram-positive Staphylococcus aureus. The bactericidal behavior has been explained through the analysis of the material optical properties, with a key role played by the creation of new electronic states within the polymer-based nanocomposites.

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Real-time variable-temperature Lorentz-corrected SAXS profiles (main plots: only the polymeric contribution; insets: initial patterns in the nanocomposites: TiO2 and polymeric contributions) obtained with synchrotron radiation for all the samples as processed in a melting experiment from 20 to 76 °C at 8 °C/min.
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f2-ijms-14-09249: Real-time variable-temperature Lorentz-corrected SAXS profiles (main plots: only the polymeric contribution; insets: initial patterns in the nanocomposites: TiO2 and polymeric contributions) obtained with synchrotron radiation for all the samples as processed in a melting experiment from 20 to 76 °C at 8 °C/min.

Mentions: Real time variable-temperature SAXS experiments were also performed to estimate long spacing values and the effect of TiO2 incorporation. PCL-TiO2-0 profiles, as well as those represented in the distinct insets of Figure 2 show the initial profiles during heating for all of the samples analyzed. Several characteristics are common independently of TiO2 content: (a) an important shift of the peak to lower s values (i.e., a rise of long spacing, LSAXS, since s = 1/d and d = LSAXS) with increasing temperature and this fact indicating changes in the PCL lamellar thickness, in its amorphous layer thickness or in both of them; (b) the existence of a periodicity peak after melting of the polymeric matrix in all the nanocomposites (see the insets in Figure 2 for the distinct hybrids). This correlation peak is ascribed to a characteristic spacing between TiO2 nanoparticles [19]. Therefore, two specific contributions should be initially taken into consideration: the one associated with differences in electronic density between crystallites and amorphous regions in the PCL component and that regarding the presence of TiO2 in the resulting materials.


Biodegradable polycaprolactone-titania nanocomposites: preparation, characterization and antimicrobial properties.

Muñoz-Bonilla A, Cerrada ML, Fernández-García M, Kubacka A, Ferrer M, Fernández-García M - Int J Mol Sci (2013)

Real-time variable-temperature Lorentz-corrected SAXS profiles (main plots: only the polymeric contribution; insets: initial patterns in the nanocomposites: TiO2 and polymeric contributions) obtained with synchrotron radiation for all the samples as processed in a melting experiment from 20 to 76 °C at 8 °C/min.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3676781&req=5

f2-ijms-14-09249: Real-time variable-temperature Lorentz-corrected SAXS profiles (main plots: only the polymeric contribution; insets: initial patterns in the nanocomposites: TiO2 and polymeric contributions) obtained with synchrotron radiation for all the samples as processed in a melting experiment from 20 to 76 °C at 8 °C/min.
Mentions: Real time variable-temperature SAXS experiments were also performed to estimate long spacing values and the effect of TiO2 incorporation. PCL-TiO2-0 profiles, as well as those represented in the distinct insets of Figure 2 show the initial profiles during heating for all of the samples analyzed. Several characteristics are common independently of TiO2 content: (a) an important shift of the peak to lower s values (i.e., a rise of long spacing, LSAXS, since s = 1/d and d = LSAXS) with increasing temperature and this fact indicating changes in the PCL lamellar thickness, in its amorphous layer thickness or in both of them; (b) the existence of a periodicity peak after melting of the polymeric matrix in all the nanocomposites (see the insets in Figure 2 for the distinct hybrids). This correlation peak is ascribed to a characteristic spacing between TiO2 nanoparticles [19]. Therefore, two specific contributions should be initially taken into consideration: the one associated with differences in electronic density between crystallites and amorphous regions in the PCL component and that regarding the presence of TiO2 in the resulting materials.

Bottom Line: TEM evaluation provides evidence of an excellent nanometric dispersion of the oxide component in the polymeric matrix, with aggregates having an average size well below 100 nm.Presence of these TiO2 nanoparticles induces a nucleant effect during polymer crystallization.The bactericidal behavior has been explained through the analysis of the material optical properties, with a key role played by the creation of new electronic states within the polymer-based nanocomposites.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), C/Juan de la Cierva 3, 28006 Madrid, Spain. sbonilla@ictp.csic.es.

ABSTRACT
Nanocomposites obtained from the incorporation of synthesized TiO2 nanoparticles (≈10 nm average primary particle size) in different amounts, ranging from 0.5 to 5 wt.%, into a biodegradable polycaprolactone matrix are achieved via a straightforward and commercial melting processing. The resulting nanocomposites have been structurally and thermally characterized by transmission electron microscopy (TEM), wide/small angle X-ray diffraction (WAXS/SAXS, respectively) and differential scanning calorimetry (DSC). TEM evaluation provides evidence of an excellent nanometric dispersion of the oxide component in the polymeric matrix, with aggregates having an average size well below 100 nm. Presence of these TiO2 nanoparticles induces a nucleant effect during polymer crystallization. Moreover, the antimicrobial activity of nanocomposites has been tested using both UV and visible light against Gram-negative Escherichia coli bacteria and Gram-positive Staphylococcus aureus. The bactericidal behavior has been explained through the analysis of the material optical properties, with a key role played by the creation of new electronic states within the polymer-based nanocomposites.

Show MeSH
Related in: MedlinePlus