**2. Materials and Methods**

## *2.1. Materials*

Nanoclay/spring water hydrogels were prepared by mixing Alicún thermal station spring water (ALI, Granada, Spain) with two commercial fibrous nanoclays; sepiolite (PS9) and palygorskite (G30). Nanoclays were kindly gifted by the TOLSA group (Madrid, Spain).

Sepiolite hydrogel included in this study was prepared with a concentration of 10% (*w*/*w*) of PS9 dispersed in ALI spring water (ALIPS9, 250 g in total). Additionally, two palygorskite hydrogels (250 g each), ALIG30@10 and ALIG30@20, were also obtained and their final concentration was 10% *w*/*w* and 20% *w*/*w* of G30, respectively. The three formulations were prepared by means of a turbine high-speed agitator (Silverson LT, Chesham, UK) equipped with a high-traction stirrer head of square mesh and working at 8000 rpm for 5 min.
