Temperature controlled adsorption of polyethyleneimine on the sepiolite surface

The effects of temperature (15, 25 and 35 °C) on the adsorption properties of polyethyleneimine (PEI) on the sepiolite (Sep) surface and some properties of the Sep/PEI suspensions including their stability were studied. It was shown that the increase in temperature caused larger adsorption of PEI macromolecules on the Sep surface, which was the effect of the spacious PEI conformation at higher temperatures. Stability of the Sep/PEI suspension was also better when temperature was higher due to effective electrosteric stabilization. The obtained results indicate how the temperature influences the textural and electrokinetic properties of the Sep/PEI systems. The following analytical methods: UV–Vis spectrophotometry, XRD, nitrogen adsorption-desorption method, elemental analysis, SEM-EDX, FT-IR, TG-DSC, viscometry and zeta potential measurements were used in the performed research. The presented findings can be successfully used to create hybrid materials dedicated to water and wastewater treatment as well as in the gas capture processes.