1. CIEPQPF; Department of Chemical Engineering; University of Coimbra; Polo II, Rua Silvio Lima; Coimbra; 3030-290; Portugal
2. Cires S.A. - Companhia Industrial de Resinas Sintéticas; Apartado 20, Samoqueiro - Avanca; Estarreja; 3864-752; Portugal
3. Department of Colour Science; School of Chemistry; University of Leeds; Leeds; LS2 9JT; UK