Acidic Bonding Curls Acidic Bonding Curls Acidic Bonding Curls Silicone-Free Shampoo A silicone-free and sulfate-free shampoo crafted to repair curl strength and repair weakened bonds to processed, curly hair. Acidic Bonding Curls Silicone-Free Shampoo is a gentle cleanser for curls and coils formulated with Curl-Bond Technology to build bonds and repair curl strength from the inside. Featuring a formula without silicone, this shampoo works to hydrate and restore curls.