**4. Conclusion**

Chemical modification of cotton cellulose in the fabric form was effected through periodate oxidation treatment and chitosan treatment in the consecutive steps under different conditions. A single-step process was also devised for preparation of the same modified cotton. The idea in both cases was to create functional groups in the molecular structure of cotton such as aldehyde and carboxyl groups to expedite strong interactions with chitosan. Modified cotton fabrics processed as per the two processes were monitored, nitrogen content, carbonyl content, tensile strength and elongation at break in addition IR spectra.

**Part 2** 

**Dyeing** 

Results conclude that modified cotton fabrics processed as per the one-step process is by for better than those processed according to the two-step process. Attachment of chitosan to the fabric considerably improves the dye uptake of reactive and acid dyes resulting in greater the colour yield (K/S) as compared with the nonmodified fabric. The enhanced dyeability of the modified fabrics is attributed the reduction of the culombic repulsion between the fabric surface and the anionic dye molecules in the presence of the positively charged chitosan on the surface. The drop in fabric strength by oxidation by oxidation prior to chitosan treatment could be overcome by combining the oxidation and chitosan treatment in one-step process where the fabric is treated in an aqueous solution containing NaIO4 and chitosan.

#### **5. References**


**Part 2** 

12 Natural Dyes

Results conclude that modified cotton fabrics processed as per the one-step process is by for better than those processed according to the two-step process. Attachment of chitosan to the fabric considerably improves the dye uptake of reactive and acid dyes resulting in greater the colour yield (K/S) as compared with the nonmodified fabric. The enhanced dyeability of the modified fabrics is attributed the reduction of the culombic repulsion between the fabric surface and the anionic dye molecules in the presence of the positively charged chitosan on the surface. The drop in fabric strength by oxidation by oxidation prior to chitosan treatment could be overcome by combining the oxidation and chitosan treatment in one-step process

[1] Liu, X.D., Nishi, N., Tokura, S., & Sakairi, N. (2001). Chitosan coated cotton fiber: preparation and physical properties. Carbohydrate Polymers, 44, 233-238. [2] Varma, A.J. & Kulkarni, M.P. (2002). Oxidation of cellulose under conrolled conditions.

[3] Shin,Y., & Yoo, D.I. (1998). Use of chitosan to improve dyeability of DP-finished cotton

[4] Weltrowski, M., & Masri, M.S. (1996). Method for treatment of cellulosefabrics to improve their dyeability with reactive dyes. US Patent 5, 501, 711, 26 March.

[7] ASTM Test Methods D-1628, in "Book of Standard", ASTM, Philadelphia, PA, Part 24,

[9] Hebeish, A.A., Waly, A., Higazy, A. & Elshafei A. (2004). Hydrolytic and Oxidative

where the fabric is treated in an aqueous solution containing NaIO4 and chitosan.

Polymer Degradation and Stability, 77, 25-27.

[6] Klimova, V. A. & Zabrodina, K. S. (1966), Zhakn, 15, 726.

[8] Kubellka, P., Munk, F. & Tech, Z. (1931). Physik.12,593.

(II). Journal Applied Polymer Science, 67, 1515-1521.

[5] D. Duchene and D. Wouessidjewe, Acta pharm. Technol., 36, 1 (1991)

Degradation of Chitosan. Egyt.J.Chem.Special Issue, 102-122.

**5. References** 

1972.

**Dyeing** 

**0**

**2**

<sup>1</sup>*RIKEN*

*Japan*

<sup>2</sup>*The University of Tokyo*

**Dyeing in Computer Graphics**

Yuki Morimoto1,3, Kenji Ono1,2 and Daisaku Arita3

<sup>3</sup>*ISIT (Institute of Systems, Information Technologies and Nanotechnologies)*

In this chapter, we introduce a physically-based framework for visual simulation of dyeing. Since ancient times, dyeing has been employed to color fabrics in both industry and arts and crafts. Various dyeing techniques are practiced throughout the world, such as wax-resist dyeing (*batik dyeing*), hand drawing with dye and paste (*Yuzen dyeing*), and many other techniques Polakoff (1971); Yoshiko (2002). Tie-dyeing produces beautiful and unique dyed patterns. The tie-dyeing process involves performing various geometric operations (folding, stitching, tying, clamping, pressing, etc.) on a support medium, then dipping the medium

The design of dye patterns is complicated by factors such as dye transfer and cloth deformation. Professional dyers predict final dye patterns based on heuristics; they tap into years of experience and intimate knowledge of traditional dyeing techniques. Furthermore, the real dyeing process is time-consuming. For example, clamp resist dyeing requires the dyer to fashion wooden templates to press the cloth during dyeing. Templates used in this technique can be very complex. Hand dyed patterns require the dyer's experience, skill, and effort, which are combined with the chemical and physical properties of the materials. This allows the dyer to generate interesting and unique patterns. There are no other painting techniques that are associated with the deformation of the support medium. In contrast to hand dyeing, dyeing simulation allow for an inexpensive, fast, and accessible way to create dyed patterns. We focus on dye transfer phenomenon and woven folded cloth geometry as important factors to model dyed patterns. Some characteristic features of liquid diffusion on cloth that are influenced by weave patterns, such as thin spots and mottles are shown in Figure 1. Also, we adopted some typical models of adsorption isotherms to simply show adsorption. Figure 2 shows the simulated results obtained using our physics-based dyeing framework and a real dyed pattern. Figure 3 depicts the framework with a corresponding dyeing process.

Non-photorealistic rendering (NPR) methods for painting and transferring pigments on paper have been developed for watercolor and Chinese ink paintings Bruce (2001); Chu & Tai (2005); Curtis et al. (1997); Kunii et al. (2001); Wilson (2004). These methods are often based on fluid

into a dyebath. The process of dipping a cloth into a dyebath is called dip dyeing.

**1. Introduction**

**2. Related work**
