Journal: Science Advances
Article Title: Dynamically assembled magnetic nanoparticles in a phase transitional matrix for reconfigurable electronics
doi: 10.1126/sciadv.adw6611
Figure Lengend Snippet: ( A ) Mechanism of enhanced electrical percolation by LMOG concentration during a phase transition. The LMOG concentration influences the quality of the percolation, although the solution contains the same amount of MNPs. ( B ) Complex viscosity of ODE + LMOG (10 wt %) solution during a subsequent heating and cooling process in a single sample. ( C ) Rheological properties of ODE + LMOG solutions with varying LMOG fractions (1, 3, 5, 7, and 10 wt %) at room temperature. Strain (0.1%) is used for the tests. ( D ) Resistance changes of MNP + LMOG + ODE solutions during cooling from 90°C to room temperature. MNP density ( C particle ) is fixed at 0.3 g/cm 3 , but LMOG concentration (ϕ LMOG ) varies from 1, 3, 5, 7, to 10 wt %. ( E ) Change in resistance during repeated heating, aligning, and cooling cycles ( C particle = 0.3 g/cm 3 , ϕ LMOG = 7 wt %). ( F ) Static contact angle of LMOG + ODE solution on an iron substrate with varying LMOG concentrations at 70°C (just above T trs ). ( G ) Magnetization curve of patterned nanoparticle assemblies ( C particle = 0.7 g/cm 3 ) subjected to different LMOG concentrations and gelation processes. ( H ) Small-angle x-ray scattering (SAXS) analysis of patterned nanoparticle assemblies with different LMOG concentrations and gelation processes ( C particle = 0.7 g/cm 3 ). ( I ) Saturation magnetization ( M s ) and magnetic coercivity are obtained from magnetization curves in (G). Cluster size of nanoparticles is calculated from SAXS data in (H) using Guinier model. ( J ) Cryo-FESEM images of nanoparticle percolation (bright) and organogel matrix (dark) in the plane perpendicular to the direction of conduction. As particle percolation forms densely, it backscatters electrons more strongly, thus showing a brighter signal. Scale bars, 5 μm.
Article Snippet: The size of the nanoparticle cluster was determined using SAXS (Xenocs, XEUSS 2.0) and calculated with Guinier fitting model. To observe the effect of LMOG concentration on the assembly morphology of nanoparticles, samples with different LMOG concentrations were prepared.
Techniques: Concentration Assay, Sublimation, Viscosity