299 research outputs found

    Numerical methods for flow and transport in textile materials

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    Functionalization of cotton fabrics with polycaprolactone nanoparticles for transdermal release of melatonin

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    Drug delivery by means of transdermal patches raised great interest as a non-invasive and sustained therapy. The present research aimed to design a patch for transdermal delivery of melatonin, which was encapsulated in polycaprolactone (PCL) nanoparticles (NPs) by employing flash nanoprecipitation (FNP) technique. Melatonin-loaded PCL nanoparticles were successfully prepared with precise control of the particle size by effectively tuning process parameters. The effect of process parameters on the particle size was assessed by dynamic light scattering for producing particles with suitable size for transdermal applications. Quantification of encapsulated melatonin was performed by mean of UV spectrophotometry, obtaining the estimation of encapsulation efficiency (EE%) and loading capacity (LC%). An EE% higher than 80% was obtained. Differential scanning calorimetry (DSC) analysis of NPs was performed to confirm effective encapsulation in the solid phase. Cotton fabrics, functionalized by imbibition with the nano-suspension, were analyzed by scanning electron microscopy to check morphology, adhesion and distribution of the NPs on the surface; melatonin transdermal release from the functionalized fabric was performed via Franz’s cells by using a synthetic membrane. NPs were uniformly distributed on cotton fibres, as confirmed by SEM observations; the release test showed a continuous and controlled release whose kinetics were satisfactorily described by Baker–Lonsdale model

    High Performance Functional Bio-based Polymers for Skin-contact Products

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    Beauty masks, diapers, wound dressings, wipes, protective clothes and biomedical products: all these high-value and/or large-volume products must be highly compatible with human skin and they should have specific functional properties, such as anti-microbial, anti-inflammatory and anti-oxidant properties. They are currently partially or totally produced using fossil-based sources, with evident issues linked to their end of life, as their waste generates an increasing environmental concern. On the contrary, biopolymers and active biomolecules from biobased sources could be used to produce new materials that are highly compatible with the skin and also biodegradable. The final products can be obtained by exploiting safe and smart nanotechnologies such as the extrusion of bionanocomposites and electrospinning/electrospray, as well as innovative surface modification and control methodologies. For all these reasons, recently, many researchers, such as those involved in the European POLYBIOSKIN project activities, have been working in the field of biomaterials with anti-microbial, anti-inflammatory and anti-oxidant properties, as well as biobased materials which are renewable and biodegradable. The present book gathered research and review papers dedicated to materials and technologies for high-performance products where the attention paid to health and environmental impact is efficiently integrated, considering both the skin-compatibility of the selected materials and their source/end of life

    Graphene textile smart clothing for wearable cardiac monitoring

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    Wearable electronics is a rapidly growing field that recently started to introduce successful commercial products into the consumer electronics market. Employment of biopotential signals in wearable systems as either biofeedbacks or control commands are expected to revolutionize many technologies including point of care health monitoring systems, rehabilitation devices, human–computer/machine interfaces (HCI/HMIs), and brain–computer interfaces (BCIs). Since electrodes are regarded as a decisive part of such products, they have been studied for almost a decade now, resulting in the emergence of textile electrodes. This study reports on the synthesis and application of graphene nanotextiles for the development of wearable electrocardiography (ECG) sensors for personalized health monitoring applications. In this study, we show for the first time that the electrocardiogram was successfully obtained with graphene textiles placed on a single arm. The use of only one elastic armband, and an “all-textile-approach” facilitates seamless heart monitoring with maximum comfort to the wearer. The functionality of graphene textiles produced using dip coating and stencil printing techniques has been demonstrated by the non-invasive measurement of ECG signals, up to 98% excellent correlation with conventional pre-gelled, wet, silver/silver-chloride (Ag / AgCl) electrodes. Heart rate have been successfully determined with ECG signals obtained in different situations. The system-level integration and holistic design approach presented here will be effective for developing the latest technology in wearable heart monitoring devices

    Preparation and characterization of psf/vanillin capsules

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    La industria de detergentes y suavizantes de ropas ha ido incorporado en sus procesos la tecnología de microencapsulación de perfumes. Esta tecnología permite proteger los compuestos volátiles antes, durante y después de los procesos industriales; además, también protege las fragancias durante el ciclo de lavado; asimismo, ofrece una liberación prolongada del perfume durante el secado y almacenamiento de la ropa, haciendo que la fragancia se perciba por más tiempo. Sin embargo, algunas de las cápsulas industriales presentan una serie de desventajas tales como una baja estabilidad del material de la cápsula, una baja capacidad de encapsulación y además con el método industrial de encapsulación que actualmente utilizan es extremadamente complicado encapsular compuestos polares. Con el propósito de resolver estos problemas, se ha propuesto el uso de cápsulas de polisulfona (PSf) con contenido de vainilla y preparadas por la técnica de precipitación por inversión de fases En esta investigación, han sido exitosamente preparadas y caracterizadas cápsulas de PSf/Vanillin. Los resultados muestran que estas cápsulas pueden asegurar una alta capacidad de encapsulación de perfume, una liberación prolongada de la fragancia, una buena estabilidad del material y una protección óptima del perfume. Por todas estas cualidades, las cápsulas de PSf/Vanillin presentan el potencial de ser usadas no solo en detergentes y suavizantes de ropas, sino que también en otros productos textiles.Textile detergent and softener industries have been incorporating in their processes the perfume microencapsulation technology. This technology allows the protection of the fragrance before and during industrial processes, as well as in the product storage. Moreover, it protects the perfume during the laundry and it provides a long-lasting fragrance release after the drying and storage of fabrics. However, certain current industrial microcapsules present a number of drawbacks such as low material stability, low perfume encapsulation capacity and, in addition, with the industrial encapsulation method presently used it is extremely complicated to encapsulate polar perfumes. With the aim to solve these problems, polysulfone (PSf) capsules containing vanillin and prepared by phase inversion precipitation technique have been proposed. In this investigation, PSf/Vanillin capsules have been successfully prepared and characterized. Results show that PSf/Vanillin capsules may ensure a high perfume encapsulation capacity, a long lasting fragrance release, a good material stability, and an optimal perfume protection. Because all these qualities, PSf/Vanillin capsules have the potential to be used not only in detergents and softeners but also in other textile products

    Preparation of biofunctional textiles by surface functionalization based on the nanoencapsulation technique.

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    L'abstract è presente nell'allegato / the abstract is in the attachmen

    Computer-Aided Multiscale Modelling for Chemical Product-Process Design

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    Multifunctional systems with polymer actuators : mechanochromism and peristalic pumping

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.Includes bibliographical references (leaves 105-109).The mission of the ISN is to explore the long-range vision of the role of nanotechnology in the future of soldier protection. Unprecedented survivability will arise from the cohesive and comprehensive coordination of the functions and interactions of each technology. The present work approaches these objectives with basic research to support the development of two multifunctional soldier survivability systems, pumping microfibers and mechanochromic pixels. Progress was made along the two major paths of investigation towards the realization of a pumping microfiber. Polypyrrole was chemically deposited onto copolyetherester. Tubular polypyrrole actuators at the millimeter scale were electrochemically fabricated and actuated. Mechanochromic polymers can be combined with actuating polymers to create a color changing pixel. Reflectance spectrum changes with strain in mechanochromic materials were characterized. Several pixel designs were analyzed and tested in which the polymer actuator polypyrrole induces deformation of the mechanochromic block copolymer. Integrative studies inform the overall systems architecture of the far future battlesuit. Scoping calculations to investigate battlesuit functionality requirements were performed.(cont.) The multiscale, multifunctional design solutions employed in the human body and the US Army and were studied, and the Dynamic Systems Integration Map was developed to apply the lessons learned to coordinate and leverage the many emerging survivability technologies.by Melinda Joy Cromie.S.M

    Rice straw as a valuable source of cellulose and polyphenols: Applications in the food industry

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    Background: Rice plants generate a large amount of straw after harvesting, which is currently managed mainly by incineration or used as animal bedding, animal fodder or wrapping of materials during transport. Other technological uses, such as the production of energy and biofuels, pulp and paper production or construction materials have also been described. However, due to the current European Union (EU) restrictions, alternatives for waste management must be sought. Valorisation of rice straw is aligned with the Sustainable Development Goals agenda set by the EU, since interesting biocompounds have been described in their composition and, after a successful extraction and purification, they can be used in various sectors. Scope and approach: This review gathers the most relevant works related to the valorisation of rice straw. It focuses on polyphenolic extracts and cellulose derivatives obtained by different extraction techniques, either conventional or innovative. In addition, the different applications that these compounds have in the field of food and nutrition sciences are summarized. Key findings and conclusions: Polyphenols and cellulose fractions have shown their viability to be extracted from rice straw, showing great potential as antioxidants in the food sector or as nutritional components in the development of new food or packaging materials, respectively. In conclusion, the valorisation of rice straw as a rich source of valuable compounds has been demonstrated, which currently generates serious environmental and human problems due to difficulties in its management and incineration, adding value to these underutilized residues and contributing to the circular bioeconomy concept
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