Fabrication and characterization of Hydrogels using novel directional freezing methods with possible clean water applications.

Efficient water vaporization is a critical step in several novel water harvesting, desalination, and purification technologies. In these novel technologies, water molecules are stored and recovered from intermediate porous structures such as hydrogels embedded with absorption materials. These absorption materials greatly increase the evaporation rates of the water allowing it to be recovered as pure vapor using simple illumination under sunlight or even visible-spectrum light-emitting-diodes.

As a research assistant with Professor Gang Chen’s Nanoengineering Group, housed in MIT’s Rohsenow Kendall Heat Transfer Laboratory. I worked on the fabrication and characterization of Hydrogels using novel directional freezing methods.

Key Skills : Independent research, Hydrogel fabrication, tuning of hydrogel pore structures using novel directional freezing, Lyophilizer operation, Wet lab skills: handling of hazardous substances, pipetting, use of centrifuge, fume hood, liquid nitrogen.

My main duties involved fabrication of Hydrogel samples from PVA Polymers, and using specific freeze-thaw cycles to fine tune the porous characteristics of the hydrogels. For this purpose I received training in Cryo-safety for the utilization of liquid nitrogen, as well as lyophilizer equipment operation training for the sublimation of ice within the hydrogel structure to leave behind characterizable porous structures.

Figures 1-3: Images of Fabricated Hydrogel samples, Two samples freezing on copper columns chilled in liquid nitrogen, and a time lapse setup monitoring hydrogel sample in lyophilizer after several freeze-thaw cycles

I would frequently check in with my project mentor to provide progress updates on sample production, troubleshoot any issues in the fabrication process, and figure out next steps. I would otherwise work independently, carrying out literature reviews, fabricating samples, and running experiments within the lab.