Recent outbreak of the COVID-19 pandemic has changed the world dramatically, posing profound challenges to our healthcare infrastructure, economic systems, social and cultural life but also to our freedom. What this pandemic made us realize so far, is that, despite the tremendous advances in medicine and pharmacy, in the initial moments, which are crucial in the containment of spreading of any pandemic, the key role is played by the non-pharmaceutical measures. These measures are the ones that bridge the time between pandemic outbreaks and the development of drugs or vaccines and are crucial for the number of human lives spared. Smart textiles and novel materials as part of the personal protective equipment (PPE) and telemedicine are crucial factors in the healthcare system. Here, we present an overview on the use of textiles in the fight against pandemics, in the past and current COVID-19, we analyze the morphology of the commonly used face masks, made of cotton and typically used polypropylene (PP). We also present the perspective that smart textiles, wearable technologies and novel materials are offering in the fight against future pandemics, mainly as part of the personal protective equipment and telemedicine.

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Focusing on application aspects of the rubber nanocomposites and the production and testing of industrial-sized samples, this study was performed in two phases. First, natural rubber (NR)/organomontmorillonite (OMMT) nanocomposites containing 2-14 phr OMMT were prepared on a laboratorysized two-roll mill. The vulcanization behavior and mechanical properties of NR/OMMT composites were compared with a referent NR compound containing 60 phr carbon black (N330) as a reinforcing filler. The x-ray diffraction (XRD) analyses showed a predominant intercalated structure for all OMMT nanocomposites. As a result, the organoclay behaved as an effective reinforcement for NR, even at loadings as low as 2 phr. This nanocomposite exhibited an improvement in tensile strength of 29% and in elongation at break of 61% in comparison with the referent NR/N330 compound. With the estimated optimal filler content, in the second phase, bulk NR/OMMT-5/steel samples were successfully produced for dynamic testing. The dynamic moduli were investigated by the method of forced vibrations. Compared to the NR/N 330 samples, NR/OMMT-5 samples showed improved hysteresis, with very low dissipating energy per cycle and significantly reduced Mullins effect.Keywords: organo-montmorillonite; nanocomposites; natural rubber; dynamic properties ДОБИВАЊЕ И СВОЈСТВА НА ПРИРОДНА ГУМА НАПОЛНЕТА СО ОРГАНСКИ МОДИФИЦИРАН МОНТМОРИЛОНИТ: ОД ЛАБОРАТОРИСКИ ПРИМЕРОЦИ ДО МАСИВЕН МАТЕРИЈАЛИстражувањата во овој труд се направени во две фази фокусирајќи се на применливоста на нанокомпозитите на база на гума и на добивањето и карактеризација на примероци со индус-триски димензии. Прво беа подготвени лабораториски примероци нанокомпозити природна гума (NR)/органски модифициран монтморилонит (OMMT) со 2-14 phr OMMT на лабораториски дво-валјак. Вулканизацијата и механичките својства на композитите NR/OMMT се споредувани со референтен примерок на природна гума наполнета со саѓи (N330). Рендгенската дифракција (XRD) покажа дека кај сите нанокомпозити со OMMT доминира интеркалирана структура. Како резултат на тоа, органски модифицираната глина се однесува како ефикасен зајакнувач на природната гума, дури и при концентрации од само 2 phr. Нанокомпозитот се одликува со јачина на истегнување за 29 % поголема од онаа на референтниот примерок со саѓи (NR/N330), како и со зголемено издолжување (за 61 %). Во втората фаза, по определување оптимална количина на полнилото, произведени беа индустриски примероци NR/OMMT и сендвич-структура NR/OMMT-5/челична A. Ivanoska-Dacikj, G. Bogoeva-Gaceva, A. Buzarovska, I. Gjorgjiev, L. Raka Maced. J. Chem. Chem. Eng. 33 (2), 249-265 (2014) 250 плоча наменета за динамичко тестирање. Динамичкиот модул на материјалот е испитуван со методот на принудни вибрации. Произведениот масивен нанокомпозитен материјал NR/OMMT-5 се одликува со подобрена хистереза, многу ниска енергија на дисипација за циклус и значително намален Mullin-ов ефект во споредба со референтниот материјал NR/N330. Клучни зборови: органски модифициран монтморилонит; нанокомпозити; ...

Hybrid nanofillers composed of different ratios of carbon nanotubes (CNTs) and sodium montmorillonite (MMT) were prepared by physically pulverizing both materials in powder form. Their dispersion behavior was investigated in different solvents (water, toluene and carbon tetrachloride). UV-vis spectroscopy showed that the absorbance at 550 nm for the CNTs becomes more intense with the increasing amount of added MMT, when water is used as a solvent, implying their improved dispersion. This is not so evident for toluene and carbon tetrachloride. TGA analyses showed that the thermal stability of the hybrid nanofillers increases with the increase of the MMT content. Raman spectroscopy confirmed the mutual interaction between CNTs and MMT, demonstrated by shift of D and G band with addition of MMT in the nanofiller.

A successful optimization of the electrospinning parameters for obtainment of biodegradable polyester urethane (DP) webs of fibers, neat and graphene oxide (GO) modified, was performed. The effect of the processing parameters (distance between the needle tip and the collector, applied voltage, and flowing rate), solution type and polymer concentration, on the fiber-forming process and the obtained fibers’ morphology was examined. The best homogeneity of the fibers was achieved for 12 wt% DP dissolved in 80:20 wt% mixture of chloroform and ethanol, applying similar processing parameters for the neat and modified samples (0.5 ml/h pumping rate, 15 kV applied voltage, and 150 mm distance to the collector, for the neat sample, and 0.4 ml/h, 18 kV, and 110 mm, for the GO modified samples). The main novelty of this work is the modification of DP with low quantities (0.5, 1.0 and 2.0 wt%) of GO – the “next generation” nanomaterial for stem cell control. The morphological characterization revealed a fibrous microstructure consisting of randomly oriented fibers with a diameters ranging from hundreds nanometers to couple micrometers, representing a feasible imitation of the structure of extracellular matrix (ECM). The XRD studies showed high dispersion of GO in DP matrix and even exfoliation for the sample that contains 2 wt% GO. Raman studies neatly complemented the highest filler/matrix interactions and the superior levels of dispersion for this sample. TGA was used to analyze the thermo-oxidative degradation and also to determine the actual content of GO present in the samples.