Browsing by Author "Barros, Maria Catarina"
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- Chitosan as an antimicrobial agent for footwear leather componentsPublication . Barros, Maria Catarina; Fernandes, Isabel P.; Pinto, Vera; Ferreira, Maria José; Barreiro, M.F.; Amaral, Joana S.Chitosan is being increasingly used in distinct areas such as pharmaceutical, biomedical, cosmetics, food processing and agriculture. Among the interesting biological activities that have been ascribed to chitosan, the antimicrobial activity is probably the one to generate the higher number of applications. Within this work the role of chitosan in diverse applications has been reviewed with particular emphasis for those exploring its antimicrobial power. Furthermore, the mechanism to explain the antimicrobial activity of this emerging biopolymer is also discussed. The viability of using chitosan to effectively provide a functional coating for leather products was presented through an experimental case study. Results confirmed the potential of using this strategy to create antimicrobial leather products to be used, e.g., in the footwear industry.
- Chitosan as an antimicrobial agent for footwear leather componentsPublication . Barros, Maria Catarina; Fernandes, Isabel P.; Amaral, Joana S.; Barreiro, M.F.; Pinto, Vera; Ferreira, Maria JoséIn the footwear industry, microorganisms’ growth can pose problems of material deterioration with associated unpleasant smell and generate possible infections in susceptible individuals. Generally, footwear presents high relative humidity conditions that enable the growth of bacteria and fungi. Additionally, leather itself and some tannery agents such as oils and greases, provide a substrate where microorganisms can grow. In the foot, microtraumas caused by ingrown nails, abrasions and lacerations can allow microbial invasion through epidermis, resulting in skin infection. In this work, the applicability of chitosan functional coatings to leather was tested, with the purpose to develop new base materials to produce footwear components. The leather treated with chitosan was then studied for its antibacterial properties against 3 different bacteria.
- Revestimentos funcionais de base quitosano desenvolvimento de aplicações para a indústria do calçadoPublication . Barros, Maria Catarina; Barreiro, M.F.O termo revestimento emerge do conceito clássico de protecção, tendo sido desenvolvido para responder a um determinado estímulo. Deste conceito surgem dois tipos de revestimentos principais, os revestimentos orgânicos e os revestimentos funcionais, podendo também existir um terceiro tipo revestimento obtido a partir da junção dos dois anteriores, denominados camadas híbridas. O quitosano é um polímero que apresenta características motivadoras para o seu uso como revestimento funcional. A sua grande abundância faz dele um recurso economicamente atractivo com características de elevado interesse para determinadas áreas específicas, incluindo a biomédica. Uma das características mais focadas nas suas aplicações é o seu poder antimicrobiano. Neste trabalho foi estudada a viabilidade de se fabricarem revestimentos funcionais de base quitosano, com ou sem a incorporação de aditivos, e a sua aplicabilidade à indústria do couro como material base para a produção de componentes para a indústria do calçado. O desenvolvimento experimental compreendeu três partes distintas para a formação de revestimentos funcionais de base quitosano: (1) Formação de microcápsulas pelo método de coacervação simples, utilizando um sistema óleo-em-água; (2) Formação de filmes de quitosano pelo método da evaporação do solvente e (3) Formação de filmes incorporando microcápsulas. Fazendo uma análise detalhada ao processo produtivo do couro, os revestimentos funcionais desenvolvidos experimentalmente, podem ser inseridos em duas etapas do processo: Curtume ou Acabamentos. The terminology coating emerges from the classical concept of protection that has been developed to respond to a given stimulus. From this concept arise two main types of coatings, organic and functional coatings. It may also be defined a third type of coating obtained from the combination of the last two, called hybrid layers. Chitosan is a biopolymer with unique properties for being used as a functional coating. Its abundance makes it an economically attractive resource with characteristics suited for specific areas, for example, biomedical applications. One of the most relevant characteristic is its antimicrobial activity. In the present work the feasibility of producing chitosan-based functional coatings was studied, with or without the incorporation of additives and, thereafter, its applicability to the leather as a base material to produce footwear components evaluated. The experimental development comprised three main topics: (1) Production of microcapsules by simple coacervation using an oil-in-water system; (2) Production of chitosan-based films by the solvent evaporation technique and (3) Production of films with incorporated microcapsules. Moreover, a detailed analysis of the leather productive process pointed out for the viability of introducing the developed functional coatings into two distinct stages of the process: Tanning and Finishing