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Opis: Skripta z naslovom »Ekologija plemenitilnih procesov« je namenjena študentom visokošolskega študijskega programa Tehnologije tekstilnega oblikovanja. Pripravljena je tako, da študente v prvih poglavjih seznani z osnovami tehnoloških procesov plemenitenja tekstilij in njihovo ekološko problematiko. Poseben problem v tekstilni industriji predstavljajo odpadne tehnološke vode, saj so močno obremenjene, vsebujejo različne kemikalije in tekstilna pomožna sredstva, različne tipe organskih barvil, imajo ekstremne pH-vrednosti in visoke vrednosti kemijske potrebe po kisiku (KPK) in biokemijske potrebe po kisiku (BPK), vsebujejo fosfate, sulfate in ostale soli, tenzide, maščobe in olja ter različne tipe težkih kovin. V nadaljevanju so v gradivu predstavljeni alternativni mediji in postopki plemenitenja, ki za dosego izbranega učinka plemenitenja porabijo manj kemikalij in tekstilnih pomožnih sredstev, manj energije in tako vplivajo na manjšo obremenitev okolja. Poseben poudarek je na alternativnih tehnikah obdelave, ki vključujejo avtomatizacijo, ki dodatno vpliva na nižjo porabo vode in energije, manjšo količino odpadkov, odpadnih vod in emisij toplogrednih plinov ter na večjo produktivnost, varnost pri delu in optimalno izrabo delovnega časa. Pridobljeno znanje bo študentom omogočilo, da bodo poleg temeljnih znanj poznali tudi napredne pristope in tehnologije pri razvoju in plemenitenju sodobnih inženirskih materialov.
Ključne besede: ekologija, plemenitenje, tekstilni materiali, napredni postopki, odpadne vode
Objavljeno v DKUM: 16.12.2024; Ogledov: 0; Prenosov: 20
Celotno besedilo (5,38 MB)
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Opis: This bachelor thesis depicts the chemical degradation of polyurethane and melamine formaldehyde, which are representatives of thermosets. A high–pressure reactor was used to perform chemical degradation. The effectiveness of the chemical degradation of the selected thermosets was monitored by measuring pH, total organic carbon (TOC) and total nitrogen (TN) of the liquid residues. The remaining solid material was characterized by infrared spectroscopy and the mass loss was determined. Using these analytical methods, it was concluded that the chemical degradation depends on the temperature and the duration of the reactions as well as the reaction medium. It was found that “white liquor” is a more effective medium for the chemical degradation of polyurethane and melamine formaldehyde than water.
Ključne besede: chemical degradation, polyurethane, melamine formaldehyde, FTIR
Objavljeno v DKUM: 22.10.2024; Ogledov: 0; Prenosov: 0

Opis: Plastics play a crucial role in our daily lives. The challenge, however, is that they become waste and contribute to a global environmental problem, increasing concerns about pollution and the urgent need to protect the environment. The accumulation and fragmentation of plastic waste, especially micro- and nanoplastics in aquatic systems, poses a significant threat to ecosystems and human health. In this study, the decomposition and fragmentation processes of conventional and biobased plastic waste in simulated water bodies (waters with different pH values) and in real water systems (tap water and seawater) are investigated over a period of one and six months. Three types of plastic were examined: thermoplastic polyethylene terephthalate and thermoset melamine etherified resin in the form of nonwovens and biobased polylactic acid (PLA) in the form of foils. Such a comprehensive study involving these three types of plastics and the methodology for tracking degradation in water bodies has not been conducted before, which underlines the novelty of the present work. After aging of the plastics, both the solid fraction and the leachate in the liquid phase were carefully examined. The parameters studied include mass loss, structural changes and alterations in functional groups observed in the aged plastics. Post-exposure assessment of the fragmented pieces includes quantification of the microplastic, microscopic observations and confirmation of composition by in situ Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy. The leachate analysis includes pH, conductivity, turbidity, total carbon and microplastic size distribution. The results highlight the importance of plastic waste morphology and the minor degradation of biobased PLA and show that microfibers contribute to increased fragmentation in all aquatic systems and leave a significant ecological footprint. This study underlines the crucial importance of post-consumer plastic waste management and provides valuable insights into strategies for environmental protection. It also addresses the pressing issue of plastic pollution and provides evidence-based measures to mitigate its environmental impact.
Ključne besede: polylactic acid, polyethylene terephthalate fabric, melamine etherifed resin fabric, aquatic environment, fragmentation, waste disposal
Objavljeno v DKUM: 09.09.2024; Ogledov: 73; Prenosov: 20
Celotno besedilo (3,73 MB)
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Opis: The reuse of decontaminated disposable medical face masks can contribute to reducing the environmental burden of discarded masks. This research is focused on the effect of household and laboratory washing at 50 °C on the quality and functionality of the nonwoven structure of polypropylene medical masks by varying the washing procedure, bath composition, disinfectant agent, and number of washing cycles as a basis for reusability. The barrier properties of the medical mask were analyzed before and after the first and fifth washing cycle indirectly by measuring the contact angle of the liquid droplets with the front and back surface of the mask, further by measuring air permeability and determining antimicrobial resistance. Additional analysis included FTIR, pH of the material surface and aqueous extract, as well as the determination of residual substances—surfactants—in the aqueous extract of washed versus unwashed medical masks, while their aesthetic aspect was examined by measuring their spectral characteristics. The results showed that household washing had a stronger impact on the change of some functional properties, primarily air permeability, than laboratory washing. The addition of the disinfectant agent, didecyldimethylammonium chloride, contributes to the protective ability and supports the idea that washing of medical masks under controlled conditions can preserve barrier properties and enable reusability.
Ključne besede: medical masks, washing, detergent, didecyldimethylammonium chloride, air permeability, antimicrobial activity, residuals
Objavljeno v DKUM: 15.03.2024; Ogledov: 333; Prenosov: 26
Celotno besedilo (3,67 MB)
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Opis: In the scope of the Doctoral Dissertation, a polysaccharide based stimuli-responsive smart material with controlled drug release was developed by using electrospinning technique, which allowed to form stimuli-responsive nanofibers with rapid visual detection of pH change in the wound bed along with anti-inflammatory activity. Incorporation of halochromic dyes into electrospun nanofibers has been an intriguing area for wound healing applications. Furthermore, it is known that the pH value within the wound milieu directly and indirectly influences all biochemical reactions taking place in the process of wound healing. It has been proven that the surface pH of a wound plays an important role in wound healing as it helps control infection and increases the antimicrobial activity, oxygen release, angiogenesis, protease activity, and bacterial toxicity. Therefore, visual pH monitoring without the need of removing the wound dressing was one of the aims of the Doctoral Dissertation. Produced stimuli-responsive wound dressings were characterized according to their morphological and chemical properties using well-known techniques such as, rheometry, conductivity, Scanning Electron Microscopy (SEM),CIE Lab, Thermogravimetric Analysis (TGA), UV/VIS Spectrophotometry, and Attenuated Total Reflection Infra-Red Spectroscopy (ATR-IR). Responsiveness of the nanofibers were achieved by integration of different halochromic dyes [bromocresol green (BCG), bromothymol blue (BTB) and thymol blue (TB)] to obtain a range of pH values. To tackle the problem of leaching of the dyes, a complexing agent; poly-diallyldimethylammonium chloride (PDADMAC) was integrated and an analysis on the formation of complexation was performed by using pH-potentiometric titration and Quartz Crystal Microbalance with Dissipation (QCM-D) and Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) techniques. Additionally, release tests were performed to prove that the leaching of the halochromic dyes is reduced significantly up to 97%. Furthermore, the responsiveness of the nanofibers was investigated by exposing the nanofibers to different buffer solutions with pH values 4, 7 and 10. The color change of the nanofibers were analyzed using the CIE Lab system while a visual color shift was observed according to their characteristics. Lastly, diclofenac (DFC), an anti-inflammatory drug molecule was integrated to the system and drug release studies were performed by using Franz diffusion cells. A controlled release of the drug molecule (DFC) to the wound bed is achieved and quantitative evaluations were done. Consequently, the drug release from the smart wound dressings were identified to have two separate profiles during the release. The mathematical models that were identified to fit to the kinetics are, first-order, Korsmeyer-Peppas, and Higuchi release model, confirming the controlled drug release.
Ključne besede: stimuli-responsive, polysaccharides, wound dressings, halochromism, controlled drug release, smart materials
Objavljeno v DKUM: 06.10.2023; Ogledov: 426; Prenosov: 42
Celotno besedilo (8,48 MB)