Investigation of Poly-(N-isopropylacrylamide) (PNIPAM) for water collection applications

  • Mashael Abdulla AlShehhi

Student thesis: Master's Thesis


The climate of the UAE is arid with rapid economic development and fast-growing population, which may lead to future water demand that exceeds the limited fresh water supplies. One of the methods of supplying water to satisfy the future demands in the UAE could be water harvesting from humidity. This report addresses the use of smart thermoresponsive polymer that can collect and release water from the humid atmosphere of the UAE. It focuses mainly on the adsorption and desorption processes of water from the atmosphere by polymeric material. The thermo-responsive polymer has the ability to respond to a change in temperature within the typical day-and-night cycle, which results in structural changes of the temperature-responsive polymer. This material is based on temperature-responsive polymer named Poly-(N-isopropylacrylamide) PNIPAM, which changes from hydrophilic-to-hydrophobic in aqueous solution across a lower critical solution temperature (LCST) at 32 °C. Below this temperature the PNIPAM adsorbs water and swells, and above 32 °C it expels the water and shrinks. Different chemical structures of the PNIPAM were tested for their ability to adsorption and desorption water from the humid atmosphere. The different structures included hydrogels and grafted polymer. All prepared samples were placed in a humidity chamber for adsorption test under 90% humidity and temperature below LCST of PNIPAM. After 24 hours, one of the samples tested showed a decent water adsorption capacity of 70% (1.3 g of water per 1.9 g of polymer). The water collected managed to form water drops that escape upon heating. The working samples managed to adsorb and release the water for a number of continuous cycles. The idea of using PNIPAM as a humidity absorbing material is novel, and it can be used in any place as long as there is humidity and it does not require any extensive infrastructure because it works without electrical energy.
Date of Award2015
Original languageAmerican English
SupervisorSaeed Al Hassan (Supervisor)


  • Applied sciences
  • Collection
  • Isopropylacrylamide
  • Poly-(n-isopropylacrylamide)
  • Water
  • Chemical engineering
  • 0542:Chemical engineering

Cite this