catecholamine coated maghemite nanoparticles for asphaltene adsorption/desorption process

In this study, a nano-layer polydopamine (pda) coated superparamagnetic maghemite nanoparticles (mnps) was applied to investigate the asphaltene adsorption-desorption behavior using a model solution. in this process, fourier-transform infrared spectrum (ft-ir) spectroscopy of the polydopamine/mnp core/shell (mnp@pda) before and after asphaltene adsorption was indicated the attachment of asphaltene molecules on the polymeric nano-adsorbent surface. the isotherms and kinetics of the asphaltene adsorption process on the mnp@pda were studied. the good prediction of asphaltene adsorption by the modified langmuir model indicated that adsorption occurs on an mnp@pda surface by multilayer adsorption. also, within the kinetic models, the double-exponential model can fit the experimental data well. the obtained results revealed that about 90% removal for asphaltene happened within 30 min which can be acceptable. the results of this study showed that natural polymers can be used for surface modification of nanoparticles and use it successfully for asphaltene adsorption from prepared asphaltene-toluene solution.