Fig. 5. XRD profiles of the conversion products with adding 0.3 g Gly (a), Arg (b) and Glu (c) respectively after soaked in 0.15 M K2HPO4 with varied pH 3–12 at 37 °C for 10 d. Note that the pH values appearing in the figures only indicate the initial ones before soaking the CC particles. The solution pH, originally adjusted at 3, increased to 8–9 due to acid decomposition of CC when the CC particles were soaked in the solution. For solution of initial pH 6, 7, 10 and 12, it reached pH 8–9, 8–9, 9–10 and 11–12 in final stage, respectively.
