Photothermal membrane distillation (PMD) is a promising configuration of membrane distillation (MD), which can overcome the temperature polarization problem and allows using solar thermal energy. However, the effect on wetting of the incorporation of plasmonic nanoparticles (NPs) into a membrane is still unknown. This paper aims supporting the development of photoplasmonic membranes for PMD, by studying their wetting in vacuum MD operation, thanks to two methods recently developed in our group: the ex-situ detection of dissolved tracer intrusion (DDTI) and an in-operando optical method. Different composite membranes with Ag-NPs included in PVDF were elaborated by phase-inversion for checking if the proportion of NPs influences membrane wetting. This study demonstrates the importance of considering wetting in the earlier stages of the development of new membranes. Indeed, whatever the NP load, at global scale partial wetting was detected and the pore wetting ratio increased with the NP load, whereas the PVDF membrane remained un-wetted. Wetting dynamics was highly impacted by the presence of NPs and wetting occurred faster with increasing NP load, thus reducing the duration of the MD operation for the highest load. For limiting short-term wetting, a limited proportion of Ag-NPs (<= 25 %) is recommended to membrane manufacturers or developers.