Exploring the methods of making nano-scale cellulose
Date Issued
2004
Date
2004
Author(s)
Chao, Ming-Yu
DOI
zh-TW
Abstract
In the present study the cotton cellulose were degraded for the preparation of nanoscale-cellulose particles by application of three methods: acid hydrolysis, ozonolysis and milling. The relations between the particle size distributions and the degrading methods were investigated.
In the acid hydrolysis, the fiber suspended in an acidic solution (H2SO4:HCl＝3:1(v/v)) and dealt by supersonic treatment in a water bath at 70 ℃. It resulted that the mean particle size in differential volume was ranged from 128.7 μm to 13.48μm in 24 hours, and its corresponding count mean diameter was 3 μm to 1.037μm.
While in the ozonolysis, the cotton fiber was treated by the ozone with concentration 80 mg/min (20 hr) and 70 mg/min (28 hr), respectively, at 80℃. It showed that the rate of degradation was quick and efficient due to high ozone concentration, which resulted in smaller particles. Here, the mean particle size in differential volume was ranged in 49.86~128.7μm, and the count mean diameter was 1.753~3μm.. Note that the smaller particles can be further degraded to oligosaccharides in the ozonolysis.
By the application of mechanical milling, the cellulose fiber was degraded to more smaller particle with higher efficiency in comparision with the previous two methods. The mean particle size in differential volume was ranged from 128.7μm to 2.278μm in 3 hours, and more than 25 % particles were smaller than 882 nm. The count mean diameter was from 3μm to 645 nm with more than 25 % particles being smaller than 475 nm.
In general, mechanical milling shows the most powerful and efficient method to reach nanoscale-cellulose. As the same degree of degradation was demanded, ozonolysis and acid hydrolysis required longer reaction time to obtain nano-particles.
Subjects
臭氧降解
奈米顆粒
奈米
纖維素
機械研磨
nano
cellulose
nanoparticle
ozonolysis
mechani
Type
thesis
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