Cellulose powder (CF-11, Whatman) was used as the
raw material. The weight-average molecular weight (Mw)
was determined to be 3.46 104 with static laser light
scattering (DAWN DSP, Wyatt Technology Co. Ltd.) in
NaOH/urea aqueous solution. Sodium carboxymethylcellulose
(CMC, 2.43 104) was analytical-grade reagent purchased
from Shanghai Chemical Agents Co. Ltd. The
degree of carboxymethyl substitution (DS) is 0.7, which is
the number of substituents per sugar ring. Bovine serum
albumin (BSA, molecular weight = 67 kDa) was purchased
from Sigma. Epichlorohydrin (ECH) (1.18 g/mL) was analytical-
grade, and was used without further purification.