**2.2. Pigment leaching and estimation of extraction yields**

To select the best solvent for Osage orange, distilled water and other co-solvents, such as water-acetone, and water- ethanol mixtures all of analytical grade, were tested at concentra‐ tions of 10% v/v. 2 g of Osage orange powder (Hands Ashford NZ, LTD, ChristChurch, NZ) was suspended in 20 cm3 of solvent, and in thermostatic as well ultrasonic baths at 60 ◦C, for 120 min. Once water-acetone co-solvent, and ultrasonic assisted extraction were chosen as the preferable technique of extraction, 10 % w/v Osage orange powder, dissolved in (2.5- 25) % v/v acetone, at (25- 60) o C, for 30- 120 min, were carried out to determine the standardiza‐ tion method of extraction. [24]

### **2.3. Dyeing and mordanting**

The compounds, osajin, iso-osajin, pomiferin, and iso-pomifcrin have been characterized and their chemical structures determined. They are isoflavones with the following structures

As well as Osage orange was applied as an eco-friendly dye acting as one of the environ‐ mental problems solutions. New concepts in the cleaner production are being evaluated to

The use of ultrasonic as a renewable source of energy in textile dyeing has been increased due to many advantages associated with it [22-25]. Ultrasonic energy represents a promising technique for assisting silk treatment, dyeing, and mordanting processes in comparison with the conventional heating technique. Sonic energy succeeded in accelerating the rate of, dye‐ ing, and mordanting at lower temperatures rather than the conventional heating technique Therefore, the present investigation was aimed at identifying the most appropriate leaching solvent for Osage orange pigments to produce an optimum concentrated extract used for dyeing protein fibers; silk and wool fabrics. This has been carried out ultrasonically in com‐ parison with the classical thermal method, using water, in addition to the co-solvents of wa‐ ter-acetone, and water-ethanol mixtures at different concentrations, temperature and time intervals. The optimum condition of the efficiency of ultrasonic assisted dyeing and mor‐ danting methods of Osage orange extraction on the quality of the dyed protein based mate‐

Degummed and bleached plain Habotain silk fabric, and 100% mill scoured wool fabric pur‐ chased from Sherazad Com. New Zealand, were further washed with a solution containing 0.5 g/L of sodium carbonate and 2 g/L of non-ionic detergent (Nonidet ® P 40 Substitute purchased from *Sigma- Aldrich NZ. Ltd*.), keeping the material to liquor ratio at 1:50, for 30

C. The scoured materials were thoroughly washed and dried at ambient tem‐

solve the high water and energy consumption in textile industries.

as shown in Figure 3. [19, 21].

210 Eco-Friendly Textile Dyeing and Finishing

**Figure 3.** Chemical Structure of iso-pomifcrin

rials were determined

**2. Experimental**

**2.1. Materials**

min. at 40-45o

perature. [23]

1 % Osage orange extract was filtered and used as a dyeing bath. Silk and wool samples were added to the extract, and the dyeing parameters were studied ultrasonically keeping the material to liquor ratio at L: R of 1:30, for time intervals varied between 30- 120 min, at temperatures from 30-60o C. In terms of the pH used for dyeing; the pH values ranging from (3-11) were carried out to control the dye uptake.

On studying the mordanting methods, the optimum concentration of 8% w/v Osage orange extract was carried out. Stock solutions of 50 gm/ l alum and 25 g/l mixture of each of alum and cream of tartar were prepared. Two different methods of mordanting were used: (1) pre-mordanting method: the samples were first mordanted and then dyed without inter‐ mediate washing; and (2) post-mordanting method: the samples were first dyed and then mordanted. Ultrasonic assisted mordanting was carried out in comparison with the conven‐ tional heating method at 50-60o C, for 90 min, at pH 5. samples were rinsed, washed with 0.5 g/L sodium carbonate and 2 g/L of non-ionic detergent at 40-45o C for 30 min, keeping the material to liquor ratio at 1:50. Finally washed with water, and dried at ambient tempera‐ ture. [23, 26, 27]

#### **2.4. Measurements**

Dyestuff content of the dyed fabrics was determined according Kubelka–Munk equation [28] using *Cary 100 UV-Vis Spectrophotomete*r

$$f\left(R\right) = \frac{\left(1 - R\right)^2}{2R} = \frac{k}{s}$$

R is the absolute reflectance of the sampled layer, K is the molar absorption coefficient and s is the scattering coefficient.

After which the samples were tested for color fastness to light and washing according to AATCC107-1997 [29] The CIE-Lab values of the dyeings were measured and the cylindrical co-ordinates of color were determined after exposure to arc lamp irradiation for 1, 2, 4, 6, 24, 48, and 72 hrs. The colors are given in an internationally commission (CIE L\*a\*b\*) coordi‐ nates, L\* corresponding to brightness, a\* to red–green coordinate (positive sign = red, nega‐ tive sign = green) and b\* to yellow–blue coordinate (positive sign = yellow, negative sign = blue). [30-32].

$$
\Delta E^{\star}\_{\;\;ab} = \left\{ (\Delta L^{\;\;\ast})^2 + (\Delta a^{\ast})^2 + (\Delta b^{\ast})^2 \right\}^{1/2}
$$
