Immobilization of laccase from Trametes hirsutus on allumina and decolourisation of textile dyes for colour removal on effluent

Laccase (EC 1.10.3.2) is a multicopper oxidase which reduces oxygen to water and simultaneously performs one-electron oxidation of many aromatic substrates [7]. Laccases catalyze the removal of a hydrogen atom from the hydroxyl group of methoxy-substituted monophenols , ortho- and para-diphenols, but it be able also to oxidize other substrates such aromatic amines, syringaldazine, and non-phenolic compounds to form free radicals [8]

Plasma-assisted deposition of antimicrobial silver nanoparticles on medical textiles

Two of the major problems in worldwide hospitals are the healthcare-associated infections (HAIs) and the skin and soft tissue infections (SSTIs). Every year mortality rates and health costs related to HAIs and SSTIs increases. Furthermore, the antibiotic resistance is moving faster than the development of new efficient antibiotic agents so, alternatives, for antimicrobial action, are urgently needed. Silver nanoparticles (AgNPs) have been used as antimicrobial agent in wound and burn dressings, surgical sutures and medical staff uniforms revealing a noble effect on Gram positive and Gram-negative bacteria, virus and fungi, including various drug resistant strains. AgNPs have improved properties compared with larger particles that allow a unique action due to the high surface to-volume ratio. However, there are some significant problems related with AgNPs based antimicrobial textiles due to the uncontrolled immbolization and release of AgNPs leading to excessive exposure. Several methods are used to incorporate AgNPs into fabrics, however, they often consume many chemicals, energy, time and usually required special equipment and have weak adhesion to the substrate. Dielectric barrier discharge (DBD) plasma treatment can be efficiently used as a pretreatment to activate the surface of the fabrics and improve the AgNPs adhesion. This is a dry environmental friendly and low cost technology since it may be produced at ambient conditions without any chemical product

Desenvolvimento de espaços para a esterilização por irradiação ultravioleta-C (UV-C) em larga escala de Equipamentos de Proteção Individual (EPIs) nos hospitais para a sua reutilização

UV-Fast: Development of spaces for large-scale sterilization by ultraviolet-C (UV-C) irradiation of personal protective equipment (PPE) in hospitals for their reuse Desenvolvimento de espaços para a esterilização por irradiação ultravioleta-C (UV-C) em larga escala de Equipamentos de Proteção Individual (EPIs) nos hospitais para a sua reutilização FCT Project Research4Covid-19 Reference: 011_59580300

Surface chemistry of nanocellulose and its composites

Cellulose is recurrently defined as the most abundant biopolymer on planet Earth, displaying an overall estimated production rate of more than 0.2 billion tons in a single day. Cellulose prompt availability allied to it its mechanical properties made it virtually indissociable from the majority of anthropogenic commodities. Nevertheless, continuous progress demands superior features form daily common materials, being most of them adequately suited by low-cost petrochemical polymers. Fortunately, the higher Environmental awareness of the global population as well as 1 the remarkable properties of biosynthesized polymers, has driven an extensive research on a plethora of biopolymers, including cellulose. Cellulose most notable features are associated to its crystal domains, which are impressively underscored with the development of cellulose nanotechnology. Moreover, at nanoscale the cellulose surface richness in hydroxyl groups is comprehensively more available, considerably t broadening he effectiveness and potential of their interaction per se, but also by enhancing the efficacy of surface modification and functionalization. Nanocellulose surface modification was implemented almost contemporary to its discovery and characterization, and its objectives ranged between improving yield of nanocellulose production, lower its production costs, and to provide nanocellulose a completely distinct surface properties by changing its polarity, generating different functional groups, decorating it with adsorbed or tightly bound nanoparticles, and to provide additional chemical compatibility with distinct compounds to generate advanced nanocomposites. The plethora of successfully reported modifications and functionalizations underscore notable properties of both modified nanocellulose and its composites. This Chapter intends to highlight these remarkable features, hopefully widening the scope of novel applications of these impressive bio-based polymers

The urgency of measuring fluorinated greenhouse gas emission factors from the treatment of textile and other substrates

The fashion industry is responsible for up to 10% of global CO2 emissions (Niinimäki et al., 2020), and according to the United Nations Framework Convention on Climate Change the sector's emissions are expected to rise by more than 60% by 2030 (UNFCCC 2018). While the vast majority of the sector's carbon footprint results from CO2 emissions, an additional source – still unaccounted for and growing – likely results from emissions of fluorinated greenhouse gasses (F-GHGs) during the treatment of textile and leather. Indeed, fluorine-based treatment of fibers and other substrates (paper, metals, plastics, etc.) is increasingly performed using wet- or plasma-based methods to functionalize surfaces for water and oil repellence, soil and stain release, improved textile breathability, softening, dyeing ability, increased mechanical strength, reduced adherence, antibacterial and anti-odor properties, and to fabricate wrinkle-free materials. For more information see Chapter 8 of (IPCC 2019). Although F-GHG emissions only represent 2.6% of global greenhouse gas emissions, F-GHGs have long atmospheric life (up to 50,000 years for CF4) and high global warming potential (GWP, up to 23,500 for SF6). Thus, it is concerning that the atmospheric concentration of some of these gasses is higher than what is predicted through bottom-up analyses i.e., when estimating emissions using the 2006 IPCC Guidelines for National GHG Inventories for all processes and industrial sectors known to emit F-GHGs. During the 2015–2016 Technical Assessment of the 2006 IPCC Guidelines, potential emissions from the textile industry were accounted, among others, as a possible reason for the gap between top-down and bottom-up estimates of F-GHG emissions (IPCC 2016). Surprisingly, although several international and national reports refer to possible atmospheric emissions of F-GHGs during finishing of textile, carpet, leather, and paper, no corresponding emission factors (EFs) were found to have been measured and published in the open literature. For more information see Chapter 8 of (IPCC 2019). While the existing literature on the environmental impacts of textile finishing processes typically focuses on formaldehyde emissions, total volatile organic compounds (VOCs) release, and the impacts of a limited number of long chains perfluoroalkane sulfonic acids (PFASs) such as perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA), and their precursors, the literature is silent on the potential climate impacts of these compounds and other fluorinated surface treatment chemicals. Fluorinated wet treatment processes include several application techniques but about 80% of the processes use the pad-dry-cure method, where the dry fabric is immersed in a F-based finishing liquor and then squeezed between rollers before being dried and finally cured, usually at temperatures up to 180 °C. Chemicals used for wet treatment processes include fluorotelomer alcohols, and perfluoroalkyl carboxylic acids. Although such chemicals may not be GHGs by themselves, it is unclear whether fluorinated ethers, unreacted monomers or by-products formed during the deposition processes, and in the atmosphere, can produce relevant F-GHGs. For more information see Appendix 1 of (IPCC 2019). Notwithstanding, it has been proved that during the drying and curing phases, F-based off-gas emissions can be produced by the volatility of the active substances themselves as well as by their constituents through evaporative losses and cracking. For more information see Appendix 1 of (IPCC 2019). Moreover, high-GWP perfluoropolyethers were identified as being used in a number of commercial applications, including for textile treatment, increasing the concerns about the atmospheric release of these compounds. For more information see Chapter 6 of (IPCC 2019). Recently, due to the persistent and bio-accumulative nature of the chemicals used in wet-based treatment processes, several manufacturers have developed alternate plasma-based treatments for specialized fibers and substrates (Tudoran et al., 2020). Plasma technology can be tailored to achieve many desirable properties and may provide equal or even better performance than wet methods. Plasma processes can be divided into three process types: (1) plasma treatment, (2) plasma polymerization and (3) plasma etching. Plasma treatment and polymerization are the main processes of concern because they can use large quantities of F-GHG feedstocks such as CF4, C2F6, C3F6, C3F8, C4F8, C5F10, CHF3, SF6, and other larger molecules such as perfluoroalkyl acrylates to deposit thin films on a substrate. Because the application of high plasma power densities could damage fragile substrates, it is highly probable that feedstock molecules are not fully disassociated by the plasma. Further, the plasma disassociation of F-GHGs is well known to result in the formation of other F-GHG byproducts (e.g., of CF4 from C2F6). For more information see Appendix 1 of (IPCC 2019). Therefore, plasma-based fluorinated treatment of textile, carpet, leather, paper, and other substrates is expected to lead to higher F-GHG emissions than wet chemistry methods. The authors of the 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories have proposed four distinct tiered methods (Tier 1, Tier 2a, Tier 2b, and Tier 3) to account for emissions from wet- and plasma-based fluorinated treatment of textile, leather, carpet, and paper. For more information see Appendix 1 of (IPCC 2019). However, because no Tier 1 or Tier 2 default (industry average) factors are available, only the Tier 3 method is currently practicable, using equipment-specific, process-specific, or site-specific measured emission factors. Measurements should preferentially be performed by Fourier transform infrared spectroscopy (FTIR) due to part per billion (ppb) sensitivity and portability or by gas chromatography followed by mass spectrometry (GC/MS), allowing near real time measurements. Without experimentally measured emission factors, it is not possible to estimate the potential global climate impact of the above-mentioned processes. Thus, there is a critical need of consistent research on the fate and atmospheric chemistry of volatile PFASs, fluorinated ethers, perfluoropolyethers and unreacted precursors and greenhouse gas by-products formed during the wet, plasma, and other thermal coating processes used for the fluorinated treatment of textiles and other substrates. Research should particularly focus on establishing a database of experimental emission factors that can be used to estimate GHG emissions per mass of input chemicals consumed, or per surface area or mass of substrates treated. Once a representative set of emission factors will have been measured, it will then be possible to derive default (industry-average) EFs that could be used to estimate industry-wide emissions. In parallel with the measurement of emission factors to establish the industry's baseline emissions, a coordinated research effort should be undertaken to mitigate climate impacts. Emissions reduction strategies could include – in decreasing order of priority from an ecological standpoint: (1) replacement (not using fluorinated precursors that may emit F-GHGs), (2) optimization (reducing emissions through process improvements), (3) capture and recycle, and (4) abatement. While replacement may prove difficult – especially for the most demanding applications –, optimization of processes to increase the utilization efficiency of fluorinated precursors certainly appears as a viable option, especially for plasma-based processes. Indeed, previous experience in optimizing F-based plasma processes in the electronics industry have proved that it is possible to increase the utilization efficiency of the precursors, thereby reducing their consumption and overall emissions, while lowering costs and improving productivity (e.g., through shorter processing times). For more information see Chapter 6 (IPCC 2019). Also, even if complete replacement of fluorinated chemistries may not always be possible, using alternate fluorinated precursors that are easier to disassociate (e.g., NF3 instead of CF4) or have lower GWPs (e.g., c-C5F8 instead of c-C3F6) can be viable options. While capture and recycling may be costly, abatement of F-GHGs is an established technology that offers low mitigation costs for high-GWP fluorinated gasses. Indeed, combustion-, catalytic-, absorption-, hot-wet-, and plasma-based abatement solutions have been developed to provide up to 99% destruction removal efficiencies (DREs), notably in the electronics industry. For more information see Chapter 6 of (IPCC 2019). Emissions of F-GHGs from wet- and plasma-based fluorinated treatment of textile, leather, paper fibers, and other substrates may be substantial due to the large volume of materials treated and the sheer size and global nature of these industrial sectors. It is therefore urgent to measure the corresponding emissions factors and to create a comprehensive international database of such factors in order to estimate and mitigate emissions from these yet-unaccounted-for sources.Centro de Ciência e Tecnologia Têxtil (2C2T) of the Universidade do Minho for the travel expenses reimbursement through the project UID/CTM/00264/2019 of the Portuguese Fundação para a Ciência e Tecnologia (FCT

Structure properties change of ready-to-use nonwoven wiping materials over storage time

Healthcare-associated infections (HAIs) caused by the transfer of nosocomial pathogens from high-touch environmental surfaces and medical devices are responsible for significant patient morbidity, mortality and economic cost.[1] An effective cleaning and disinfection practice plays a key role in preventing cross-contaminations and spread of HAIs.[2] Traditionally, healthcare staff has used the “bucket method”, which consists of towels saturated with diluted disinfectant contained in a bucket. This method exhibits several limitations such as improper disinfectant dilution, inadequate saturation, uneven moisture distribution, unknown material compatibility and possible contamination from reusing.[3-4] Among the most effective surface disinfection methods, the nonwoven ready-to-use disinfectant wipes are increasingly accepted for decontamination of high-touch surfaces because of its convenience and reliable performance.[5] Though some research has been done on the effectiveness of commercial available disinfecting wipes in practical use.[6] Whereas their behaviour during storage remains unknown. In addition, a lower or even abolished disinfectant efficacy of the active ingredients due to their interaction with the textile materials has been also reported.[7] This project studied the ageing of the disinfecting wipes over storage time. Chloramine as a surface disinfectant and 3 commercial wiping materials of polyester, viscose, and their combination have been selected. The wipes before and after the contact with disinfectant solution were analysed by FTIR (Fourier-transform infrared spectroscopy) and DMA (Dynamic mechanical analysis).Xinyu Song acknowledges Fundação para a Ciência e Tecnologia (FCT), Portugal, for its PhD grant financial support (SFRH/BD/130028/2017). Andrea Zille also acknowledges FCT through the iFCT Research contract (IF/00071/2015) and the project POCI-01-0145-FEDER-007136 under the COMPETE and FCT/MCTES (PIDDAC) co-financed by European funds (FEDER) through the PT2020 program.info:eu-repo/semantics/publishedVersio

On the applicability of the moving line source theory to thermal response test under groundwater flow: considerations from real case studies

The classical methodology to perform and analyze thermal response test (TRT) is unsuccessful when advection contributes to heat transfer in the ground, due to the presence of a groundwater flow. In this study, the applicability, the advantages, and the limitations of the moving line source model to interpret TRT data are discussed. Two real TRT case studies from the Italian Alpine area are reported and analyzed, with both the standard infinite line source approach and the moving line source one. It is shown that the inverse heat transfer problem is ill-posed, leading to multiple solutions. However, besides minimization of the error between measurements and modeling, physical considerations help to discriminate among solutions the most plausible ones. In this regard, the MLS approach proves to be effective in the advection-dominated case. The original time criterion proposed here to disregard initial data from the fitting, based on a resistance–capacitance model of the borehole embedded in a groundwater flow, is validated in terms of convergence of the solution. In turn, in the case when advection and conduction are competitive, the MLS approach results more sensitive to ground thermal conductivity than to Darcy velocity. Although in this case a limited impact of the uncertainty in the groundwater velocity on the boreholes sizing is expected, future studies should focus on the development of a successful TRT methodology for this condition

Redox biodegradation of azo dyes

Apresentação efetuada "4th International Conference on Textile Biotechnology, Seoul, Korea, 2006

O uso da nanotecnologia nos materiais fibrosos

Apresentação efetuada na III Semana de Engenharia Têxtil – SETEX 2014, no Brasil , 201

Synthesis and characterization of silver-chitosan nanoparticles on textile

Metal nanoparticles these times have gathered huge popularity in the fields of health industry. This study focuses on synthesis of silver and chitosan nanoparticles and study their antibacterial effects and cytotoxicity when they are coated on a fabric. The prepared fabric was subjected to characterization techniques such as XPS, XRD, EDX and SEM. These tests confirmed the presence of silver nanoparticles on the surface of the fabric. Antibacterial and cytotoxicity tests were conducted, and the results exhibited that silver nanoparticles have showed good antibacterial effect on both gram positive and gram-negative bacteria and showed no cytotoxicity. The antibacterial effect was effective after 10 cycles of washing.t PLASMAMED - PTDC/CTM-TEX/28295/2017 fnanced by FCT, FEDER and POCI in the frame of the Portugal 2020 program, the project UID/CTM/00264/2019 of 2C2T under the COMPETE and FCT/MCTES (PIDDAC) co-fnanced by FEDER through the PT2020 progra