POM was used to probe the dissolution process of the p-WNPin AmimCl, as shown in Fig. 1. It can be seen that p-WNP consistedof many microfibers with diameters of 10–50 m. As time wenton, the number of undissolved fibers decreased. At the end of 3 hduration, a relatively homogeneous clear solution was obtained.These results indicate that most of the organic substance in thep-WNP was dissolved quickly in AmimCl under the mild conditions