Rozdziały
Stały URI dla kolekcjihttp://hdl.handle.net/11652/4411
Przeglądaj
9 wyniki
collection.search.results.head
Pozycja Fabric topgraphy influence on nanofibers deposition(Wydawnictwo Politechniki Łódzkiej, 2022) Ljungerg, Ida; Sánchez-Martínez, Ainhoa; Martínez-González, Inés; Mínguez-García, David; Montava, Ignacio; Díaz-García, PabloInterest in nanotechnology has increased in recent years and the textile sector has not been left out of this technology. Obtaining nanofibers opens up multiple applications in fields such as filtration. However, due to the fragility of said nanofibers, conventional textiles can serve as a support for the created nanofiber net. In this work we intend to demonstrate the influence of the weave pattern on the homogeneity of nanofibers deposited on the fabric. Two fabrics characterised by wave patterns showing different topography are studied. Authors demonstrate there is a strong influence of topography on the nanofibers deposition. Nanofibers tend to cover wave´s fibres in a higher plane first and it require longer periods to find some fibres on lower planes.Pozycja Fiber cross-section influence on the deposition of nanofibers on textile weaved structures(Wydawnictwo Politechniki Łódzkiej, 2022) Mínguez-García, David; Capablanca, Lucía; Montava, Ignacio; Díaz-García, PabloRoughness is directly related to the increase of adhesion between surfaces. Different cross section on fibres implies different longitudinal shape of fibres, altering the roughness of filaments. In this study, a procedure to evaluate the nanofibers adhesion to the substrate has been designed. In order to test it, different cross-section shapes are evaluated to demonstrate its influence on the nanofibers net adhesion. Circular, tetralobal and trilobal fibres were tested. Focused on corroborating it, two yarns with different filament fineness were also tested. Different weights are placed on an acetate film which is placed on the nanofibers net. The pressure helps the nanofiber to move to the acetate. This procedure helps to determine the influence of fibre cross-section or roughness, demonstrating the adhesion of nanofibers net on the structures is enhanced with higher roughness.Pozycja Fabrication of UV-responsive chromic system using nanospider device and its photo-fatigue behavior under continuous mode of UV irradiance(Wydawnictwo Politechniki Łódzkiej, 2022) Solanki, Utkarshsinh; Vikova, Martina; Holec, Pavel; Erben, Jakub; Vik, MichalIn this paper, we proposed the preparation of a photochromic nonwoven fabric based on photochromic nanofibers with high color response, which has excellent photochromic properties, good durability, and can quickly return to its original state. Photochromic nanofibers were colored by spiropyran (SP) class of photochromic dyes. The SP was dissolved in an ethanol solution containing polyvinyl butyral and then the composition was spined using a needle-free NANOSPIDER system. The test data of colorimetric and spectral characteristics of photochromic color change demonstrate that the prepared samples exhibit significant color changes and sufficient stability during fatigue tests. At the same time, a good agreement of the measured experimental data with the proposed theoretical model is documented, which allows estimating the total amount of energy that causes a 50% decrease in color response. This enabled the design of an accelerated UV resistance test method for photochromic textiles.Pozycja Preparation of PVDF nanofibers by optimizing solvent properties: improved solvent viscosity and evaporation rate(Wydawnictwo Politechniki Łódzkiej, 2022) He, Zhongchen; Rault, François; Mohsenzadeh, Elham; Lewandowski, Maryline; Salaün, FabienPVDF nanofibers have been intensively investigated in wearable energy harvesting because of their flexibility and piezoelectric properties. In this study, we prepared PVDF nanofibers by the electrospinning method. Different solvents like DMF and DMF/acetone with the ratio of 6/4, 5/5, and 4/6 were selected to adjust the solvent properties. SEM, FTIR, and DSC characterizations were used to characterize the morphology, structure, and β phase content of PVDF nanofibers. The results demonstrate that the electrospun PVDF nanofibers produced by using DMF/acetone have predominantly a fibre structure and increased β phase compared to electrospun samples using DMF alone as solvent. PVDF nanofibers fabricated by using DMF/acetone with a ratio of 4/6 exhibit the maximum content of β phase and the highest value of piezoelectric coefficient (d33).Pozycja Electrospun bioactive polymer/gelatin coatings for medical application - creation and investigation(Wydawnictwo Politechniki Łódzkiej, 2022) Andziukeviciute-Jankuniene, Akvile; Sinkevičiūtė, Joana; Adomaviciute, Erika; Valeika, Virgilijus; Balciunaitiene, Aiste; Jankauskaite, VirginijaSkin protects human body from negative external influences; however, it has property to be injured. There are a lot of different types of medical dressings, nevertheless, electrospun materials for medical applications are on demand due to nonwoven materials properties, such as large surface area, specific porosity, polymers suitability. Natural polymers for wound dressings are highly investigated not only for their antimicrobial and anti-inflammatory properties, but for electrospinning feasibility as well. The aim of this research is to develop bioactive polymer/gelatin coating from animal waste and investigate its feasibility for medical dressing. Polyvinyl butyral (PVB) and polyvinylpyrrolidone (PVP) as polymers were chosen due to their adhesive properties, solubility in various solvents and biocompatibility. Gelatin as bioactive polymer was chosen due to its anti-inflammatory properties. Natural Symphytum officinale (SO) extract in compositions was used. Electrospun polymeric nano/microfibers were coated with gelatin compositions. Nano/microfibers diameters and gelatin compositions droplets sizes were evaluated. It was determined that composition modification with SO has influence on used polymers nano/microfibers diameter. Plant extract addition to polymer solution induces thinner nano/microfibers. Consequently, it was ascertained that gelatin and SO composition forms high quality droplets both on PVB/SO and PVP/SO nanofibers surface.Pozycja Tunable silica nanofibrous structures in view of resolving challenging purification and separation obstacles(Wydawnictwo Politechniki Łódzkiej, 2022) Loccufier, Eva; Swanckaert, Bianca; Geltmeyer, Jozefien; Deventer, Koen; Van Hulle, Stijn W.H.; D’hooge, Dagmar R; De Buysser, Klaartje; De Clerck, KarenElectrospinning of polymer nanofibers has been studied extensively and has shown to be possible via stable, reproducible and controllable processes. The development of more inert nanofibers with higher thermal and chemical resistance extends the application field towards challenging purification and separation obstacles of today. By direct electrospinning of a tetraorthosilicate (TEOS) based sol–gel solution, without a sacrificing carrier polymer, dense ceramic silica nanofibers can be produced. A humidity or temperature induced wettability-switch from highly hydrophobic after electrospinning to superhydrophilic makes the resulting silica nanofibrous membranes ideal for fast gravity-driven separation, especially upon tuning the surface chemistry and the functionalization. This is showcased for the separation of immiscible liquids and the photocatalytic degradation of organic micro-pollutants.Pozycja TPU-based elctrospun nanofibers assembled with nonwoven structure for face mask’s application(Wydawnictwo Politechniki Łódzkiej, 2022) Hebie, Ali; Moretti, Joséphine; Mohsenzadeh, Elham; Gidik, Hayriye; Lewandowski, Maryline; Vroman, PhilippeThe outbreak of Coronavirus Disease 2019 (COVID-19) has triggered great global public health concerns. Face masks are essential tools to reduce the spread of SARS-CoV-2 from human to human. However, there are still challenges with extending the serving life and maintaining the filtration performance of the current commercial masks. Filters composed of ultrafine fibers with diameters down to tens of nanometers have the potential to physically block viruses. The idea of developing an electrospun membrane with these ultrafine fibers to be integrated into the mask seems an innovative idea. A right mechanism must be developed to make it happen. This study presents the development of an electrospun membrane on a non-woven support by using thermoplastic polyurethane (TPU) for face masks.Pozycja Design and development of a nanofiber reinforced multilayered cloth face mask(Wydawnictwo Politechniki Łódzkiej, 2022) Palak, Handan; Kayaoglu, Burcak KaragüzelThe use of medical masks in daily life has become inevitable due to the Covid-19 pandemic. Especially at the beginning of the pandemic, the supply of face masks was unable to meet the demand. Also, medical masks are causing plastic waste since they are not sustainable. Accordingly, cloth masks have the potential to be an environmentally friendly and sustainable alternative to medical masks. In this study, it was aimed to develop two and three layered cloth masks, and investigate the effects of fabric parameters of the masks on the bacterial filtration efficiency (BFE). Four fabrics with different cover factors were woven. The raising finishing was applied to the outer layer to increase the filtration by closing the pores on the surface. An electrospun nanofiber layer was also used as a mid-layer to improve bacterial filtration. All BFE results were higher than the minimum standard BFE of 90%. The results showed that an electrospun mid-layer was more effective for increasing the BFE compared to raising finishing onto the outer layer of the masks. The BFE improved slightly when the cover factor of the fabric increased.Pozycja Multilevel full factorial design in optimizing polymer type and blend ratio for PLA/PCL and PLLA/PCL electropsun webs(Wydawnictwo Politechniki Łódzkiej, 2022) Öztemur, Janset; Özdemir, Suzan; Sezgin, Hande; Yalçın-Eniş, İpekBiopolymers have gained attention for tissue engineering researches in the last decade. Polycaprolactone(PCL), poly(lactic acid) (PLA), and poly(L-lactide) (PLLA) are highly popular biopolymers for scaffoldfabrication due to their biocompatibility and biodegradability. These polymers can be used as blend form to highlight their strengths such as morphological, mechanical, and biological. The blending ratio has an impact on the end product properties so, the structural features of the polymers like molecular weight and viscosity should be considered before surface development. In this study, electrospun fibroussurfaces with various ratios (10/90, 20/80, 30/70, 40/60, and 50/50) of PLA/PCL and PLLA/PCL blends are produced and the effect of polymer type as well as the blending ratio is examined. The findings of the fiber diameter research revealed that depending on the molecular weights of the polymers, the blend ratio has a statistically significant effect on fiber diameter.