**5. Ultrasonic in textile industry**

grafted onto a cotton fabric via gamma-ray irradiation to improve the hydrophobic and

The results show that the fabric became highly hydrophobic and oleophobic with the contact

In the other research, a novel coating formulation for improving the UV protection property on cotton, PET, and cotton/PET fabrics was prepared, and gamma rays were applied for surface curing. Aluminum potassium sulfate (Alum) was used individually and in binary coat with

Microwaves comprise electromagnetic radiation in the frequency range of 300 MHz–300 GHz. As the polar or charged particles in a reaction medium fail to align themselves as fast as the direction of the electric field of microwaves changes, friction is created to heat the medium [18]. They can penetrate into a material and heat the deep layers of the material strongly when they release their energy. Microwave irradiation offers a number of advantages over conventional heating methods, including using less energy, offering a higher heating rate, and offering the

Sulfonating a PET fabric by dilute sulfuric acid and microwave irradiation has been found to

PET fabric has been immersed in H2SO4 solutions with different concentrations at room

PET fabric samples were then dried at 50°C for 30 min and then irradiated with microwaves at 2450 MHz using a commercial 700 W microwave oven for 4 min. The SEM images of both

produce a super-hydrophilic PET fabric, and the fibers sustained minimal damage.

for water and sunflower oil, respectively (**Figure 3**) [16].

**Figure 3.** Photographs of water and sunflower oil drops on the grafted sample [16].

Zinc Oxide (ZnO), to induce the UV-blocking properties [17].

**4. Microwave applications in textile industry**

ability to more quickly start and stop heating.

and 140o

oleophobic properties.

314 Radiation Effects in Materials

angles of above 150o

temperature for 5 min.

Ultrasound technology is among the irradiation technologies whose applications in different branches of industries have soared in recent years.

Ultrasound technology has been extensively used for detecting defects in a large variety of industrial components and materials. Using ultrasound waves through the air is not the first choice due to the high impedance mismatch between air and most of transducer and compo‐ nent materials. As a result, a higher impedance substance is employed as a couplant to optimize the acoustic energy transfer to the sample, for example, water or a coupling gel. Nevertheless, in some processes, it is not allowed to use a wet coupling, which makes room for a specific category of applications usually named as noncontact or airborne ultrasound. An example of this is the inspection of textile goods, where a wet coupling substance could degrade the fabric and/or slow the manufacturing process.

Several previous investigations have shown that ultrasonic technology enhances mass transfer during some textile processing steps such as desizing, scouring, bleaching, mercerizing, and dyeing of natural fabrics.

Pazos-Ospina et al. in 2015 presents a design methodology for half-curved airborne ultrasonic arrays based in cellular ferroelectret film. The geometry of the array proposed allows them focus naturally in the vertical plane and electronically in the horizontal one, obtaining similar spatial resolution in both directions. Theoretical predictions and simulated results were validated with a developed array prototype designed to operate at frequencies between 50 kHz and 300 kHz. The potential of the device was shown by inspecting different textile samples in transmission mode. This multi-transducer design is a low-cost alternative to the use of composite 2D arrays in noncontact ultrasonic inspections [22].

Cleaning of materials is one of the most important applications of ultrasound. However, the use of ultrasonic energy for textile washing has been searched many years without achieving commercial development. The cleaning action of ultrasonic energy is due to cavitations. The implosion of vapor bubbles inside the cleaning auxiliaries and near the surface to be cleaned imposes such stress on the surface that erodes the contaminant and removes the impurities. On the other hand, stable cavitations, may also cause the dispersion of the particles of contaminant removed from the surface.

**Figure 5.** Basic scheme of the ultrasonic process [23].

An ultrasonic system for the continuous washing of textiles in liquid layers based on a procedure has been designed and constructed by Gallego-Juarez et al. in 2010. The system incorporates, as the main part, special plate transducers capable for high-power operation without the interaction of perturbing undesired vibration modes. This system has shown very good washing behavior either with the laboratory or the semiindustrial set-up (**Figure 5**) [23].

Ultrasound technology has been extensively used for detecting defects in a large variety of industrial components and materials. Using ultrasound waves through the air is not the first choice due to the high impedance mismatch between air and most of transducer and compo‐ nent materials. As a result, a higher impedance substance is employed as a couplant to optimize the acoustic energy transfer to the sample, for example, water or a coupling gel. Nevertheless, in some processes, it is not allowed to use a wet coupling, which makes room for a specific category of applications usually named as noncontact or airborne ultrasound. An example of this is the inspection of textile goods, where a wet coupling substance could degrade the fabric

Several previous investigations have shown that ultrasonic technology enhances mass transfer during some textile processing steps such as desizing, scouring, bleaching, mercerizing, and

Pazos-Ospina et al. in 2015 presents a design methodology for half-curved airborne ultrasonic arrays based in cellular ferroelectret film. The geometry of the array proposed allows them focus naturally in the vertical plane and electronically in the horizontal one, obtaining similar spatial resolution in both directions. Theoretical predictions and simulated results were validated with a developed array prototype designed to operate at frequencies between 50 kHz and 300 kHz. The potential of the device was shown by inspecting different textile samples in transmission mode. This multi-transducer design is a low-cost alternative to the use of

Cleaning of materials is one of the most important applications of ultrasound. However, the use of ultrasonic energy for textile washing has been searched many years without achieving commercial development. The cleaning action of ultrasonic energy is due to cavitations. The implosion of vapor bubbles inside the cleaning auxiliaries and near the surface to be cleaned imposes such stress on the surface that erodes the contaminant and removes the impurities. On the other hand, stable cavitations, may also cause the dispersion of the particles of

and/or slow the manufacturing process.

contaminant removed from the surface.

**Figure 5.** Basic scheme of the ultrasonic process [23].

composite 2D arrays in noncontact ultrasonic inspections [22].

dyeing of natural fabrics.

316 Radiation Effects in Materials

Recently, attempts have been made to use acoustic cavitation for washing textiles. Ultrasonic cleaning has been widely employed to remove submicron-sized contaminant particles adhering to solid substrates (e.g., photo masks and wafers) in semiconductor industry. Ultrasonic waves traveling in a liquid result in cavitation and thus produce bubbles. The bubbles exhibit rich dynamic behaviors such as translation, oscillation, growth, and collapse in response to the varying acoustic pressure [24].

In the recent decade, the application of ultrasonic irradiation as an advanced oxidation process has attracted much attention because of the generation of high amounts of •OH radicals due to the ultrasonic cavitation. The ultrasonic waves result in the rapid growth and subsequently, collapse of the cavitation bubbles, which produces extremely high pressure (up to 1800 atm) and temperature (as high as 5000 K) in the bubbles. The high temperature, together with the high pressure, named "hot spots" leads to the generation of •OH within the gas–liquid transition zone near the bubbles and bulk solution as a result of the water dissociation. It has been demonstrated that the catalytically enhanced ultrasonic irradiation based on the appli‐ cation of semiconductors, known as sonocatalysis, has higher degradation efficiency and lower processing time than that of sonication alone.

Darvishi Cheshmeh Soltani et al. in 2016 used a porous clay-like support with unique charac‐ teristics for the synthesis and immobilization of ZnO nanostructures to be used as a sonoca‐ talyst for the sonocatalytic decolorization of methylene blue (MB) dye in the aqueous phase. They concluded that the sonocatalytic activity of ZnO–biosilica nanocomposite (77.8%) was higher than that of pure ZnO nanostructures (53.6%). Increasing the initial pH from 3 to 10 led to increasing the color removal from 41.8% to 88.2%, respectively. Increasing the sonocatalyst dosage from 0.5 to 2.5 g/L resulted in increasing the color removal. They also concluded that the ZnO–biosilica nanocomposite can be a suitable sonocatalyst for the sonocatalytic decolor‐ ization of colored solutions with high reusability potential and cost-efficiency [25].

As an alternative to the existing finishing technologies, a facile one-step sonochemical route has been suggested for uniform deposition of inorganic nanoparticles on the surface of solid substrates, including textiles.

The antimicrobial finishing is very important for medical textiles, decreasing the risk of hospital-acquired infections.

Petkova et al. in 2016 report a simultaneous sonochemical/enzymatic process for durable antibacterial coating of cotton with zinc oxide nanoparticles (ZnO NPs). The novel technology goes beyond first enzymatic preactivation of the fabrics and subsequent sonochemical nanocoating and is designed to produce "ready-to-use" antibacterial medical textiles in a single step.

A multilayer coating of uniformly dispersed NPs was obtained in the process. The pretreat‐ ment with enzymes causes better adhesion of the ZnO NPs on the surface of cotton fabrics. The NPs-coated cotton fabrics inhibited the growth of *S. aureus* and *E. coli*, respectively, by 67% and 100% [26]

Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. Ultrasonic-assisted dyeing of cellulosic fibers has already proved to be a better choice among conventional dyeing by many researchers.

Khatri et al. in 2016 reported ultrasonic dyeing of nanofibers. They chose cellulose nanofibers and dyed with two reactive dyes, CI reactive black 5 and CI reactive red 195. Results revealed that the ultrasonic dyeing produced higher color yield (K/S values) than the conventional dyeing. The color fastness test results depicted good dye fixation. Also they have reported that ultrasonic energy during dyeing does not affect surface morphology of nanofibers. The results conclude successful dyeing of cellulose nanofibers using ultrasonic energy with better color yield and color fastness results than conventional dyeing [27].
