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The application of nanocoatings in the textile finishing is increasingly being explored because they open a whole new vista of value-addition possibilities in the textile sector. In the present work, low temperature pulsed DC magnetron sputtering method was used to create functional TiO2 nanocoatings on poly(lactic acid) textile fibres surfaces. In this study, the principal objectives in the application of TiO2 nanocoatings to textile materials are to impart UV protection functions and self-cleaning properties to the textile substrates. The TiO2 films were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy, transmission electron microscopy, UV-visible spectroscopy and contact angle analysis. The Photocatalytic activity of the films was tested by measuring the photodegradation rates of rhodamine-B dye aqueous solution under UV light irradiation. The ultraviolet protection function was tested according to the Australian/New Zealand standards. It was observed that the TiO2 nanocoatings on poly(lactic acid) fibres showed an excellent ultraviolet protection (> 40) function and the photocatalytic efficiency was maintained even after a strong washing treatment.

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Multiwalled carbon nanotubes (MWCNTs), both oxidized and amine functionalized (triethylenetetramine-TETA), have been used to improve the mechanical properties of nanocomposites based on epoxy resin. The TGA and XPS analysis allowed the evaluation of the degree of chemical modification on MWCNTs. Nanocomposites were manufactured by a three-roll milling process with 0.1, 0.5, and 1.0 wt % of MWCNT-COOH and MWCNT-COTETA. A series of nanocomposites with 5.0 wt % of reactive diluent was also prepared. Tensile and impact tests were conducted to evaluate the effects of the nanofillers and diluent on the mechanical properties of the nanocomposites. The results showed higher gains (258% increase) in the impact strength for nanocomposites manufactured with aminated MWCNTs. Optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to investigate the overall filler distribution, the dispersion of individual nanotubes, and the interface adhesion on the nanocomposites.Particularly, the epoxy resins are thermosetting polymers used in the development of structural composites due to their high tensile strength, good chemical resistance, high adhesion, and low shrinkage. 18,19 However, the cross-linked resins are generally brittle materials with low fatigue resistance to heat and impact, which limits their application. CNTs can contribute to the improvement of mechanical and thermal properties, such as tensile strength, modulus of elasticity, impact resistance, and increase in the glass transition temperature in high-performance nanocomposites. 19,20 Guo and co-workers dispersed 2.0, 4.0, 6.0, and 8.0 wt % of oxidized MWCNTs directly in epoxy resin Additional Supporting Information may be found in the online version of this article.

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Resumo: Este trabalho apresenta uma caracterização de sistemas epoxídicos a base do éter diglicidílico do bisfenol A (DGEBA), curado com dois co-monômeros do tipo amina cicloalifática -piperidina (Pip) e 4,4'-diamino-3,3'-dimetildiciclohexilmetano (3DCM) -antes e após a aplicação de irradiação com raios gama. Variações nas propriedades mecânicas e térmicas foram investigadas através de medidas do módulo elástico, da temperatura de transição vítrea e do perfil de degradação dos materiais. Foi possível observar que uma dose de irradiação de 50 kGy provoca variações sutis em propriedades como rigidez e estabilidade, que são relevantes do ponto de vista fundamental. Este trabalho permite afirmar que as variações de propriedades observadas não implicam em impacto negativo na utilização destes sistemas como biomaterial na área médica, considerando a etapa de esterilização por radiação de que são objeto. Palavras-chave: Polímeros epoxídicos, raios gama, degradação, reticulação. Effect of Gamma Irradiation on Mechanical and Thermal Properties of DGEBA/ Cycloaliphatic Amine Networks with Potential for Medical ApplicationsAbstract: Two epoxy polymers based on diglycidyl ether of bisphenol A (DGEBA), cured with piperidine (Pip) and 4,4'-diamino-3,3'-dimethyldicyclohexylmethane (3DCM), were characterized before and after treatment with γ irradiation. The changes in the mechanical and thermal properties were studied by elastic modulus, glass transition temperature and degradation temperature measurements. A dose of 50 kGy of irradiation caused subtle variations in properties such as rigidity and stability, which are relevant from the fundamental point of view. The variations do not imply on negative impact when considering the stage of sterilization during the use of these systems as a biomaterial in the medical area. Keywords: Epoxy polymers, gamma rays, degradation, crosslinking. IntroduçãoExiste na atualidade uma grande demanda por biomateriais que possam melhorar a qualidade de vida do ser humano [1][2][3] . Os polímeros epoxídicos apresentam propriedades otimizadas tais como dureza, tenacidade, resistência química, baixa contração, assim como excelente adesão, que são associadas à natureza estrutural dos monômeros que formaram a rede tridimensional [4,5] . Estes materiais poliméricos apresentam potencialidade para serem utilizados em algumas aplicações médicas, porque manifestam boas propriedades biológicas em paralelo às propriedades mecânicas adequadas [6][7][8][9] . Esta afirmação pode ser corroborada pelos estudos prévios do grupo com estes polímeros, usando ensaios biológicos in vitro de compatibilidade que mostraram reduzida atividade trombogênica com o sangue humano e não citotoxicidade com células de ovário hanster chinês [10] . Neste trabalho, os polímeros formulados com aminas cicloalifáticas mostraram melhor comportamento biológico, ou seja, reduzido comportamento trombogênico quando comparado às aminas alifáticas. Além disto, as aminas cicloalifáticas apresentam maior tempo de manipulação que as aminas alifá...

Graphene-based 2D nanomaterials possess unique physicochemical characteristics which can be utilized in various biomedical applications, including the transport and presentation of chemotherapeutic agents. In glioblastoma multiforme (GBM), intratumorally administered thin graphene oxide (GO) nanosheets demonstrate a widespread distribution throughout the tumor volume without impact on tumor growth, nor spread into normal brain tissue. Such intratumoral localization and distribution can offer multiple opportunities for treatment and modulation of the GBM microenvironment. Here, the kinetics of GO nanosheet distribution in orthotopic GBM mouse models is described and a novel nano-chemotherapeutic approach utilizing thin GO sheets as platforms to non-covalently complex a proteasome inhibitor, bortezomib (BTZ), is rationally designed. Through the characterization of the GO:BTZ complexes, a high loading capacity of the small molecule on the GO surface with sustained BTZ biological activity in vitro is demonstrated. In vivo, a single low-volume intratumoral administration of GO:BTZ complex shows an enhanced cytotoxic effect compared to free drug in two orthotopic GBM mouse models. This study provides evidence of the potential that thin and small GO sheets hold as flat nanoscale platforms for GBM treatment by increasing the bioavailable drug concentration locally, leading to an enhanced therapeutic effect.