1 Sara K. Murase 1 , María Teresa Casas 1 , Juan Carlos Martinez 3 , Francesc Estrany 1,2 , Lourdes Franco 1,2* , Jordi Puiggalí 1,2, * 1 Departament d'Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028, SPAIN 2 Center for Research in Nano-Engineering, Universitat Politècnica de Catalunya, Campus Sud, Edifici C’, C/Pasqual i Vila s/n, Barcelona E-08028, SPAIN 3 ALBA Synchrotron Light Facility, Ctra. BP 1413 km. 3,3 | 08290 | Cerdanyola del Vallès| Barcelona | SPAIN (www.albasynchrotron.es) Correspondence to: Jordi Puiggalí (E-mail: Jordi.Puiggali@upc.edu) REVERSIBLE CHANGES INDUCED BY TEMPERATURE IN THE SPHERULITIC BIREFRINGENCE OF NYLON 6 9