@article{Mat Latif_Musa_Balakirisnan_Sulaiman_2021, title={The effect of surfactant concentration on nanoparticles surface wettability during wettability alteration of oil-wet carbonate rock}, volume={15}, url={https://journal.ump.edu.my/jmes/article/view/3733}, DOI={10.15282/jmes.15.2.2021.05.0630}, abstractNote={<p>Previous studies reported that the presence of surfactant increases nanoparticles surface wettability by in-situ surface activation. On the other hand, the excess of surfactant concentration has an inverse effect on particle hydrophobicity by altering it to be hydrophilic back. Hence, this study presents an experimental investigation of wettability alteration by using a surfactant-nanoparticles system by using cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) surfactant, and hydrophilic silicon dioxide (SiO<sub>2</sub>) and partially hydrophobic silicon dioxide (PH SiO<sub>2</sub>) nanoparticles. The nanoparticles surface wettability and the wettability alteration of oil-wet carbonate rock were measured by using the contact angle method. The result shows that the contact angle of the oil-wet carbonate rock was most reduced by using CTAB-hydrophilic SiO<sub>2</sub>, from 112.00<sup>o</sup> to 28.35<sup>o</sup>. The excess of surfactant concentration (beyond CMC) shows an inverse effect on particle surface wettability, however, induces the water-wetness of the carbonate rock. Besides, the hydrophilic SiO<sub>2</sub> shows a more effective effect as a wettability modifier than the PH SiO<sub>2</sub>, in the absence and presence of CTAB or SDS surfactant.</p>}, number={2}, journal={Journal of Mechanical Engineering and Sciences}, author={Mat Latif, Wan Mohd Shaharizuan and Musa, M. S. M. and Balakirisnan, A.S.M. and Sulaiman, W. R. W.}, year={2021}, month={Jun.}, pages={7993–8002} }