Methodology for determination of magnetic force of polymeric nanocomposites

PLA-b-PEG/magnetite hyperthermic agent prepared by Ugi four component condensation

“…The magnetic products obtained were also characterized by magnetic force tests, the results of which are shown in Table 4 and Figure 13. As expected, the chemical modification of magnetite and its covalent linkage to PEG and PLA by Ugi four component condensation decreased the values of magnetic force of the composite [40,74,75] when compared to free magnetite and aldehyde magnetite. These results are in agreement with those reported for the organic modification of magnetite [76][77][78].…”

“…XRD results from magnetite, magnetite modified with aldehyde and magnetic composite are shown in Figures 12 curves a)-c) respectively. All the tested materials present peaks at 2" equal to 30.3°, 35.7°, 43.3°, 53.9°, 57.3° and 63.0°, which confirm the spinel structure of the crystal, characteristic of this iron oxide [68], proving that Ugi four component condensation does not change the particles' nature [40,27,69]. Moreover, the crystal size of magnetic particles was calculated by the Scherrer equation [70].…”

“…Measurement of magnetite, aldehyde-modified magnetite and UMC were performed as reported by our group elsewhere [40]. Briefly the samples were kept under a variable magnetic field (0-790 Gauss), calibration of the test was performed by using reduced Fe, CoSO 4 ·7H 2 O and CuSO 4 ·5H 2 O as standard for high level, medium level and a lack of magnetic force, respectively [41][42][43].…”

Green polyurethane synthesis by emulsion technique: a magnetic composite for oil spill removal

“…As described in previous works [9,[15][16][17][18][19][20][21][22][23][24][25] , our group is interested in the maghemite synthesis and we used similar approaches to obtain this nano material. Specifically in the present work, aqueous solutions of hydrochloric acid (2 M), ferric chloride (2 M), and sodium sulfite (1 M) were prepared.…”

“…Optical microscopy was performed in a Bel Photonics microscope, aiming the calculation of the particles diameter. Magnetic force test of maghemite/composite was performed following the procedure established in our laboratory [22] . Simultaneous TGA-DSC analysis were performed using a PerkinElmer STA-6000 in the temperature range between 28-670 °C in 20mL/min flow of nitrogen and heating rate of 10 °C/min.…”