Cellulose acetate plasma treatment

The CF4 plasma treatment yields F/C peak area ratio of approximately 1.5 for both cellulose and cellulose acetate films. When those surface-tagged films were immersed in liquid water, the fluorine atoms, which are detectable by XPS, decreases as a function of the immersion time. Figure 25.9 depicts change of F Is/C Is ratio as a function of immersion time in water, which shows that the disappearance rate of F Is peak is much higher for the semicrystalline cellulose film than that for the amorphous cellulose acetate film. These data actually compare the extent of X interaction rather than the degree of crystallinity, indicating that x interaction overwhelms the degree of crystallinity. 

Phosgene has been employed in the modification of the surfaces of cellulose-acetate membranes used for water desalination and waste water treatment [1450]. Similarly, phosgene has been used to surface-modify porous diaphragms for electrolytic cells [324]. Aluminium and aluminium-based alloys can be etched at a high rate when COClj is used in a mixed gas plasma [1004], as can semiconductors (see Section 9.12). 

Figure 9-37. Permeability of the polymer membrane from acetate cellulose with respect to He, H2, CO2, and CH4 as function of microwave plasma treatment time o, Hhc , Hh a, ricoz +, ncH< microwave pulse power 2 kW pulsing period 2 ms pulse duration 100 /ts gas pressure in the microwave discharge chamber 2 Torr nitrogen/oxygen ratio in the plasma gas N2 02 =4 1 flow rate of the plasma gas 40 cm /s.

In the woik of Olde Riekerink et al. (2002), one type of UF (cellulose triacetate, CTA) membrane and one type of RO (cellulose acetate blend, CAB) membrane were selected for CO2 plasma modification. CTA ultrafilters are well known for their low fouling properties and CAB membranes are widely used for desalination. CO2 plasma treatment resulted in the gradual etching of the membrane s dense top layer. 

Kusumocahyo, S.P., Kanamori, T., Iwatsubo, T., Sumaru, K. and Shinbo, T. 2002. Development of polyion complex membranes based on cellulose acetate modified by oxygen plasma treatment for pervaporation. 

Tsai PP, Wadsworth LC, Roth JR (1997) Surface modification of fabrics using a one-atmosphere glow discharge plasma to improve fabric wettability. Text Res J 67(5) 359-369 Noeske M et al (2004) Plasma jet treatment of five polymers at atmospheric pressure surface modifications and the relevance for adhesion. Int J Adhes Adhes 24(2) 171-177 Shenton MJ, Stevens GC (2001) Surface modification of polymer surfaces atmospheric plasma versus vacuum plasma treatments. J Phys D Appl Phys 34(18) 2761-2768 Baltazar-Y-Jimenez A et al (2008) Atmospheric air pressure plasma treatment of lignocellu-losic fibres Impact on mechanical properties and adhesion to cellulose acetate butyrate. Compos Sci Technol 68(l) 215-227... 

A. Baltazar-y-Jimenez, M. Bistritz, E. Schulz, and A. Bismarck, Atmospheric air pressure plasma treatment of lignocellulosic fibres Impact on mechanical properties and adhesion to cellulose acetate butyrate. Compos. Sci. Technol. 68(1), 215-227 (2008). 

Cellulose based ultrafine fibers with superhydrophobicity have been prepared. Park et al. [115] electrospim cellulose triacetate fibers using methylene chloride/ethanol as the solvent system and further converted the fiber mat to be superhydrophobic by plasma treatment. Another method using sol-gel coating to converting cellulose acetate fiber mats fi om superhydrophilicity to superhydrophobicity was done by Ding et al. [116]. The resultant superhydrophobic fiber mats are useful for many potential applications such as self-cleaning materials and contamination prevention, due to their poor wettability. 

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