**1. Introduction**

Recently, the usage of unique dyes and finishing agents has had a substantial influence on textiles' functionality. The dyeing of textiles with multi-functional characteristics has attracted significant interest in recent years. Nanotechnologies and nanomaterials offer a wider application potential for preparing functional textiles, such as flame retardant, self-cleaning, wrinkle-resistant, antistatic, antimicrobial, and UV-protective, etc. [1–14] In recent years, several approaches to metal and metal oxide NP fabrication and application have been developed to impart functionalities to different types of textile substrates [15–23]. In addition, nanomaterials, such as gold and silver nanoparticles, stabilized by opportune functional capping agents, have been used as a novel class of functionalizing nanofillers either themselves [24–29] or for the functionalization of different types of materials (such as concrete, glass, geopolymer and also embedded in coloring or antibacterial coatings), especially for textile fabrics [30].

The coloration of fabric/fiber can be achieved through a combination with metal nanoparticles by means of the particular optical properties of plasmon nanomaterials, called localized surface plasmon resonance (LSPR), producing brilliant and vivid colors,

**Citation:** Elmaaty, T.A.; Raouf, S.; Sayed-Ahmed, K.; Plutino, M.R. Multifunctional Dyeing of Wool Fabrics Using Selenium Nanoparticles. *Polymers* **2022**, *14*, 191. https://doi.org/10.3390/ polym14010191

Academic Editor: Sándor Kéki

Received: 30 November 2021 Accepted: 31 December 2021 Published: 4 January 2022

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which are different from traditional dyes in that they are not the chromophore of traditional dyes but the shape and size of nanoparticles that determine the colors [31,32]. This has recently motivated research activities to directly employ metal nanoparticles in the dyeing of different textile substrates to overcome color fading and high water and energy consumption problems associated with conventional dyeing methods. Furthermore, excessive exposure to dyes may cause respiratory problems and skin irritation and increase risk of cancer [33]. Hence, several different approaches have been developed to impart colors and functionalities to diverse fabrics/fibers, such as cotton, wool [34–41], silk [42–45], bamboo [46], ramie [47], viscose and acrylic [48] using noble metal nanoparticles via a self-assembly or in-situ synthesis methods.

Owing to the localized Surface Plasmon Resonance (LSPR) property of selenium nanoparticles (Se-NPs), they exhibit adaptable colors depending on the synthesizing measures. Besides, Se-NPs have strong cytotoxicity towards a broad range of microorganisms, low toxicity to human cells, high selectivity, and long-term durability [49]. Se-NPs have significant antimicrobial and antioxidant activity, which have been widely reported in the literature [50–52], and their applications in textile fabrics have been reported once by Joanne Yip et al. [53] as an antimicrobial agent for polyester fabric.

In our previous study, cotton and polyester were colored with silver and gold NPs via a printing technique to render different functions of fibrous materials [54]. Subsequently, Se-NPs were used in the wool fabric printing process to fabricate antimicrobial textiles with low cytotoxicity [55]. In the current study, wool fabrics were dyed with Se-NPs in a different way to produce multifunctional fabrics with brilliant stable colors in one step and compare between the results obtained from both dyeing and printing techniques.

### **2. Experimental**

#### *2.1. Materials*

The fabrics used here were 100% scoured and bleached wool. Sodium hydrogen selenite, vitamin C and polyvinylpyrrolidone (PVP) were purchased from *Loba Chemie, India*. In addition, the other chemicals used in this study were of commercial grade.
