Acidic and basic sites on SVTPUP@ZnONPs were determined by Boehm titration method

Acidic and basic sites on SVTPUP@ZnONPs were determined by Boehm titration method (Boehm, 1994). Acid site were neutralized by 0.1 M NaOH, while basic site were neutralized by 0.1 M HCl. The results clear that SVTPUP@ZnONPs contains 0.87 and 0.47 mmol/g of acidic and basic sites, so acidic character was mainly controlled in the surface which make it better sorption for cationic dyes (Br.G, To.B) and azo dyes (Tr.B).
The DC electrical conductivity (?DC) value of ZnONPs is 5.8×10-6 ?1 m-1, but for SVTPUP@ZnONPs (7.1×10-8 ?1 m-1) which is greater than SVT-PUF (1.23×10-8 ?1 m-1) because of adding ZnONPs to PUF change electric properties for composite to be better. The conductivity influenced by movement of free charge or increasing number of charge carriers 24 , consequently the ZnONPs increased polar domain and that raise conductivity.