Ureasil–polyether hybrid blend with tuneable hydrophilic/hydrophobic features based on U-PEO1900 and U-PPO400 mixtures

Molina, Eduardo F.; Jesus, Celso Ricardo Nogueira; Chiavacci, Leila Aparecida; Pulcinelli, Sandra Helena; Briois, Valérie; Santilli, Celso Valentim

doi:10.1007/s10971-014-3300-1

Cited by 30 publications

(27 citation statements)

References 60 publications

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“…Subsequently the solvent was removed by heating under reduced pressure to form the hybrid precursor. This hybrid precursor was subjected to hydrolysis and condensation reactions [18], promoted by adding ethanol and water and catalyst. Two catalysts were tested, HCl at a concentration of 2 M and NH 4 F at a concentration of 0,1 M. During these reactions the OH groups were progressively eliminated, leading to the formation of the films (ureasil-PPO and ureasil-PEO), in which the inorganic-organic networks were joined by covalent bonds [19].…”

Section: Preparation Of Ureasil Hybrid Materialsmentioning

confidence: 99%

Development of Cutaneous Bioadhesive Ureasil-Polyether Hybrid Films

Oshiro

Carvalho

Soares

et al. 2015

International Journal of Polymer Science

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The hydrolysis and condensation reactions involved in synthesis of ureasil-polyether films influence the film formation time and the number of chemical groups able to form hydrogen bonds, responsible for the bioadhesion, with the biological substrate. The objective of this work was to study the influence of the use of an acid catalyst (hydrochloric acid) and a basic catalyst (ammonium fluoride) in the hydrolysis and condensation reactions on the time formation and bioadhesion of ureasil-polyether films. The toxicity of the films was evaluated. The MTT assay has shown cell viability of human skin keratinocytes higher than 70% of all analyzed materials suggesting low cytotoxicity. The bioadhesion of the films is strongly dependent on the viscosity and hydrophilic/hydrophobic balance of the polyether chains used to synthetize the hybrid molecules. The use of acid catalyst promotes the formation of less viscous films with higher bioadhesion. The hybrids formed by more hydrophilic PEO chains are more bioadherent, since they can interact more efficiently with the water present in the stratum corneum increasing the bioadhesion. Due to their low toxicity and high bioadhesion, the ureasil-PEO films obtained by using HCl as catalyst agent are good candidates for application to the skin as bioadhesive films.

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Section: Preparation Of Ureasil Hybrid Materialsmentioning

confidence: 99%

Development of Cutaneous Bioadhesive Ureasil-Polyether Hybrid Films

Oshiro

Carvalho

Soares

et al. 2015

International Journal of Polymer Science

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“…For semicrystalline and hydrophilic polymers (such as PEO), photoaging starts in the amorphous phase, due to the easy diffusion of oxygen through the unordered chains [53]. Accordingly, the observed decrease of the electron density contrast between the siloxane nodes and the polymeric matrix indicated a more compact structure resulting from increase of the crystalline phase fraction [54], caused by the scission of polyether chains in the amorphous phase. However, the U-PEO:Eu 3+ nanostructure was preserved, as evidenced from the maintenance of the spatial correlation between the regularly spaced siloxane cross-linked nodes.…”

Section: Effect Of Photooxidation On Structural and Nanostructural Prmentioning

confidence: 99%

“…This indicated that the more intense I(q max ) decrease observed for U-PEO:Eu 3 was due to degradation of the polyether chains. However, the effect of chain scission on the nanostructure of the amorphous U-PPO:Eu 3+ could be seen from the slight displacement of the q max position from 1.44 to 1.37 nm -1 , due to the formation of more compact structures [54]. In contrast, no systematic changes were observed in the U-PEO:Eu 3+ correlation peak position following UV exposure, suggesting that the average correlation distance between two adjacent siloxane nodes of the already compact structure was less influenced by this effect, due to the semicrystalline nature of the material.…”

Section: Effect Of Photooxidation On Structural and Nanostructural Prmentioning

confidence: 99%

Accelerated ultraviolet aging of structural and luminescent properties of the ureasil-polyether hybrid materials U-PEO:Eu3+ and U-PPO:Eu3+

Palácio

Boyer

Thérias

et al. 2019

Polymer

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Eu 3+) a concomitant decreases of the Eu 3+ complexed to urea bridges, the spatially correlated siloxane nodes, and the Judd-Ofelt parameter Ω 2 (R) were observed during the photodegradation process  The sensitivity of structural features and PL properties arising from the photoinduced degradation of ureasil-polyether films could be exploited in the fabrication of new transparent, flexible, and biocompatible UV dosimeters and sensors.

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“…Molina et al silylated amino-PEG and amino-poly(propylene) with 3-glycidoxypropyl trimethoxysilane (GPTMS) ( Table 1-3), to obtain a hybrid film with tunable hydrophilic/hydrophobic properties, in the perspective to developing stimuli-responsive delivery devices. 113 Biopolymers were also silylated, to afford the biocompatibility required for biomedical applications. Primary amines of chitosan 5 and 1-6).…”

Section: Nanostructured Hydrogels As Intermediatesmentioning

confidence: 99%