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Graphene-based functional coatings for cotton textiles were realized through an easy dip-coating procedure. Cotton fabrics were coated with a reduced graphene oxide (rGO) layer and then protected with a very thin polyurethane (PU) layer that does not affect the flexibility and the hand of the pristine cotton. The application of the rGO coating induces electrical conductivity to the fabric and the application of the PU phase increases the durability of the coatings, that show very stable surface resistivity after 10 washing cycles performed at temperatures up to 40 °C. Furthermore, the rGO and rGO/PU coated fabrics show good comfort properties, increased thermal conductivity and breathability with respect to cotton. In particular, the realized coatings allow to confine the heat transfer in correspondence of a localized heating source, which is very interesting for thermal therapy applications. Finally, the rGO/PU coated fabrics present a piezoresistive behaviour characterized by very stable electrical response to applied stretching up to 50% deformation, high sensitivity especially at low deformations with gauge factor values up to 11.7 and fast response time down to 500 ms when stretched at 100 mm/min rate at 2.5% strain. Overall, the results demonstrate that rGO/PU coated fabrics are very promising wash-durable electrically conductive e-textiles with improved comfort, enhanced thermal conductivity for possible thermal therapy applications, and piezoresistive properties for sensing applications as human motion monitoring. [ABSTRACT FROM AUTHOR]

The question addressed in this paper is whether cotton textiles mercerized with liquid ammonia (L-NH3) can be distinguished from NaOH mercerized cotton textiles with FTIR-ATR spectroscopy. In collaboration with a process-house, cotton textiles were treated with L-NH3, NaOH, neither or both. The treatment conditions were set to mimic commercial-scale operations. The samples were then analyzed with FTIR-ATR spectroscopy, and for comparison, also with powder X-ray diffraction. The analyses were aimed at detecting changes in the cellulose crystal lattice structure that result from the two mercerization processes. The measured spectra and diffractograms were evaluated both visually and with Principal Component Analysis (PCA), and the results show that with FTIR-ATR spectroscopy it was possible to differentiate between the untreated, L-NH3 mercerized and NaOH mercerized textiles, whereas with X-ray diffraction it was difficult to detect differences between the untreated and treated samples. The better performance of FTIR-ATR spectroscopy is attributed to the method being more sensitive to changes on sample surfaces, whereas X-ray diffraction results are more representative of the sample bulk. The samples were treated under conditions mimicking commercial-scale operations, which are optimized to maximize treatment speed. Hence, the mercerization induced changes are likely to be limited to sample surfaces and hence detectable with FTIR-ATR spectroscopy but not with X-ray diffraction. It is reported that Sum Frequency Generation Vibrational Spectroscopy, another surface-limited analytical method, may also be employed for detection of mercerization type, but FTIR-ATR spectroscopy has the advantages of ease of operation and the devices are less expensive. [ABSTRACT FROM AUTHOR]

In this paper, several methods of hydrophobization of cotton fabrics using the thio-ene click reaction were compared. Durable, superhydrophobic textiles were obtained in an easy way. Various variants of functionalized silsesquioxanes were used for the hydrophobization of fabrics. The synthesis of bifunctional silsesquioxanes (RSiMe2O)4(ViSiMe2O)4Si8O12 and (RSiMe2O)4(R'SiMe2O)4Si8O12 were performed via hydrothiolation of silsesquioxane derivative (ViSiMe2O)8Si8O12. Alkoxysilyl, alkyl and fluoroalkyl moieties were introduced as functional groups. Samples were prepared using four methods, differing in the modification method and the number of stages. During the research, fabrics were modified via (a) the dip-coating process, (b) carrying out thiol-ene click reactions directly on the surface of the fabric and (c) using both of these methods. The hydrophobicity of the fabric was evaluated by measuring the Water contact angle (WCA). The obtained samples were also examined using infrared analysis (FT-IR), Scanning electron microscope (SEM), and Elemental analysis (SEM–EDS). All analyses were performed before and after the washing process in order to verify the stability of the performed modifications. [ABSTRACT FROM AUTHOR]

Smart textiles have got increasing attention for potential application in personal thermal management, wearable human motion monitoring, and healthcare. However, it is still a challenge to prepare a multifunctional electronic textile with water-resistant, electro-thermal response, mechanical-sensitive performance, and antibacterial activities. Here, a multifunctional conductive cotton textile is fabricated by in-situ reduction silver nanoparticles(Ag NPs) on cotton fiber under the assistance of tannic acid, followed decorating with polydimethylsiloxane (PDMS). These obtained multifunctional textiles (cotton/TA/Ag NPs/PDMS textile) not only maintain the innate flexibility, and permeability characteristics of cotton textiles, but also exhibit rapid thermal response, outstanding long-time steady heating performance, and antifouling property. Furthermore, the cotton/TA/Ag NPs/PDMS textiles exhibit excellent strain sensing performance for potential human motions monitoring. Impressively, cotton/TA/Ag NPs/PDMS textiles show resistance to bacterial. Thus, this multifunctional cotton textile provides a new way for the study of the next generation of lightweight, portable, and wearable electronic textile devices. [ABSTRACT FROM AUTHOR]