| Cassava peel |
(A) Nitric method: NH3 3.5%, NaOH 2%, NaSO3 2%, NaClO2 2% |
— |
— |
The alkaline method had the highest yield (17.80%) and cellulose content (93.24%), with type II cellulose and a 51% crystallinity index |
— |
12
|
| (B) Sulfuric method: H2SO4 0.5 M, NaClO2 2% |
| (C) Alkaline method: NaOH 4%, NaClO 4% |
| Sugarcane bagasse |
(A) Hemicellulose removal: H2SO4 10% (v/v) |
NaOH : urea (aq.) (7 : 12) |
CA, ECH/freeze-thawing (−20, 30 °C) |
The final pulp contained 84% cellulose, 12% hemicellulose and lignin, and 4% water. Adding 40% CA formed a hydrogel with mechanical strength similar to one cross-linked with 5% ECH |
Methylene blue dye removal |
13
|
| (B) Delignification: NaOH 20% (w/v) |
Crystallinity analysis showed cellulose I and II in both hydrogels, with crystallinity indices of 49% for CA and 54% for ECH |
| (C) Bleaching: NaClO 1% (v/v) |
Porosity measurements indicated higher porosity in the CA-cross-linked hydrogel |
| Starch |
— |
Water |
CA/heating (70–80, 105 °C) |
With an increase in the content of CA as a cross-linker, the swelling degree of hydrogels drops. The highest swelling degree is 8.55 for the hydrogel with the smallest content of CA |
Drug delivery |
14
|
| Rice husk |
(A) HNO3 1 M |
— |
— |
The cellulose extraction rate was 17.4% |
— |
7
|
| (B) NaOH 1 M (24 h), NaOH 6 M (6 h) |
| (C) H2SO4 5 M (up to pH = 5–6) |
| WP |
(A) Alkaline treatment: NaOH 20% (70 °C, 2 h) |
NaOH : urea (aq.) (7 : 12) |
CA/heating (30–70 °C) |
As temperature increases, the swelling ratio decreases initially and then increases. At low temperatures, less cross-links form, while at higher temperatures, stronger hydrogen bonds between CA and cellulose improve water stability |
Agricultural medium |
11
|
| (B) Bleaching: H2O2 1.5% (70 °C, 1 h) |
