First application of chlorophyll-a as biomordant: sonicator dyeing of wool with betanin dye

► The purpose of this study is to investigate the use of chlorophyll-a as biomordant. ► The dyeing conditions and the overall fastness properties were investigated. ► Chlorophyll-a used at acidic pH enhance the dyeability of wool with betanin dye. ► Ultrasonic dyeing method enhances the fastness properties of dyed wool. ► Ultrasonic dyeing method gives higher dye exhaustion at a shorter dyeing time.