Phase transitions in bio-nanocomposites functionalized by nanoparticles

Abstract We investigated the thermal and structural behavior of the phospholipid 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) in the presence of amide-functionalized single-walled carbon nanotubes (af-SWCNTs) using differential scanning calorimetry (DSC). The modification of the structural properties of the soft nanocomposites SOPC–SWCNTs was studied at SWCNTs concentrations 0.2–1 wt%. We determined the van’t Hoff enthalpy from the DSC data and the cooperative units (CUs) involved in the gel–liquid crystal phase transition. Monitoring the CU values across varying nanoparticle concentrations indicated the presence of a threshold. Above 0.4 wt% SWCNT, the phospholipid matrix conformation becomes disrupted, leading to variations in the system's free energy. This affects the hydrophobic chains order. The reported findings provide evidence that incorporating single-walled carbon nanotubes into synthetic lipid bilayers significantly alters main phase transition, thereby enabling the tuning of membrane thermodynamic properties. Graphical abstract