Thereafter, the cone-plate geometry was lowered to the measuring gap of 211 μm, and the sample was trimmed at the edges. Strain amplitude sweep experiments were performed between 0.01% and 100% sheer strain at a fixed frequency of 6. Photodegradation experiments. Solutions of OTPh/NaDC ([OTPh] = 0.02 mg mL -1 ) and P3HT/NaDC ([P3HT] = 0.01 mg mL -1 ), and gels of OTPh/NaDC ([OTPh] = 0.006 mg mL -1 ) and P3HT/NaDC ([P3HT] = 0.005 mg mL -1 ) were irradiated using a custom-built irradiation system based on a PTI QM2 fluorimeter sample compartment coupled to the PTI irradiation system containing a xenon-arc irradiation lamp (75W). The samples were irradiated at 365 nm with a 20 nm bandwidth. Absorption spectra were collected at defined times of irradiation with one of the Cary spectrometers. As a control, the degradation was studied for OTPh (0.02 mg mL -1 ) and P3HT (0.01 mg mL -1 ) in chloroform following the same procedure. All the experiments were performed at 20 °C.