Iron 3 oxide nanopowder fe2o3

Poly(1,4-butylene adipate) diol end-capped (PBA) and Poly(tetrahydrofuran) (Terathane polyether glycol) (PTHF) with Mn 2000 g/mol, 1,4-butanediol (BD), and N, N-dimethylformamide (DMF) were purchased from Sigma-Aldrich (Steinheim, Germany). The 4,4′-diphenylmethane diisocyanate (MDI) was obtained from Fluka (Steinheim, Germany) and was freshly distilled prior to use. Iron (III) oxide nanopowder (Fe₂O₃) of <50 nm particle size (IONPs), ethylene glycol (anhydrous 99.8%), and methylene iodide (99%) were also purchased from Sigma-Aldrich. All other chemicals were used as received without further purification.

Poly(tetrahydrofuran) (Terathane polyether glycol) (PTHF) with M_n 2000 g/mol, 1,4-butanediol (BD), poly(dimethylsiloxane) bis(hydroxyalkyl) terminated (PDMS) with M_n 5600 g/mol and N,N-dimethylformamide (DMF) were purchased from Sigma-Aldrich (Steinheim, Germany). 4,4′-diphenylmethane diisocyanate (MDI) was obtained from Fluka (Steinheim, Germany) and was fresh distilled prior to use. Iron (III) oxide nano powder (Fe₂O₃) of <50 nm particle size and Iron (II, III) oxide nano powder (Fe₃O₄) of 50–100 nm particle size (SEM) were used as the magnetic particles throughout the investigation and were also purchased from Sigma-Aldrich (Steinheim, Germany).
For determination of contact angle values, four test liquids with different surface tensions [34 (link),35 ] were selected: Milli-Q purified water (Millipore, ≥18.2 MΩ cm), ethylene glycol (anhydrous 99.8%, Sigma-Aldrich, Steinheim, Germany), formamide (99%, Sigma-Aldrich, Steinheim, Germany), and methylene iodide (99%, Sigma-Aldrich, Steinheim, Germany). All other chemicals were used as received without further purification.