The impact of β-CD on 4 benzophenones (BPs), typical sunscreen agents, [namely, BP, HBP, d-HBP, t-HBP] and its resultant effect on the ultraviolet protection factor (UPF) of poplin cotton fabric are tested. Drastic enhancement in the UPF values for BPs:β-CD complexes treated fabrics is noticed (compared to the untreated/fabric treated with free BPs). The impact of β-CD on the tautomerism of hydroxyl substituted BPs are demonstrated by investigating the guest(BPs=absorbers)-host(β-CD=enhancer) process. Orientation of -OH substituted benzene towards 1° rim and positioning of C = O group of BPs in the middle of β-CD could be attributed to the steric effect driven preference of the guest molecules for achieving a rigid fit. Rigid fit rendered by β-CD improves the photostability of BPs and dissipates UVR efficiently through keto-enol tautomerization. With the highest UPF (= 51) d-HBP:β-CD complex is identified as a potential application material for producing sun-protective clothing.
Krishnamoorthy, S., Allabasha, N., Mani, M.K. et al. Effect of β-cyclodextrin on benzophenones and its impact on UVR filtration of cotton fabric through ‘guest absorber—host enhancer’ mechanism. J Incl Phenom Macrocycl Chem 103, 131–145 (2023). https://doi.org/10.1007/s10847-023-01184-3