Table 2.

Composition dependence of the gelation for the HA/chitosan mixture. The nominal charge ratio was estimated from the ratio of carboxyl groups and amino groups after taking into consideration the incomplete deacetylation of chitosan determined by NMR (SI). * Samples were too weak to perform quantitative measurements.

Mass ratio in feed (w/w) (HA/chitosan)	1.6	1.8	2.0	2.1	2.2	2.3
Nominal charge ratio (−/+)	0.87	0.98	1.09	1.14	1.20	1.25
Gelation	○	○	○	○	○	○
Polymer conc. of gel (wt%)	-*	23	25	23	24	-*
Mechanical property	very weak	weak	strong	weak	weak	very weak