*2.1. Materials*

Sodium alginate (SA) was obtained from Zhejiang Yinuo Biotechnology Company (Lanxi, China). Halloysite nanotubes (HNTs) were purchased from Xi'an Mingda Biotechnology Co., Ltd. (Xi'an, China), with a purity of 99.96%. Sigma-Aldrich (St. Louis, MO, USA) provided the use of glycerin (MW = 92.09). Cinnamaldehyde (CIN) (Purity 98%) was purchased from Shanghai Macklin Biotech Co., Ltd. (Shanghai, China) The manufacturer of the analytical pure sulfuric acid was the Xilong Chemical Factory in Shantou, Guangdong. The other reagents used in this experiment were all of analytical grade.
