3, we obtained few wires with maximum length of 500 μm (0.5 mm) directly by the particles of 8.3 nm (Figure 8d). The study on the dialysis of PEI/PAA2K-γ-Fe2O3 dispersion presented same results like PDADMAC (Figure 9): we got straight and regular wires at Z = 0.3 with L 0 = 31 ± 1 μm and at Z = 7 with L 0 = 16 ± 1 GDC-0068 ic50 μm. These results showed that the wire formation is a general phenomenon that does not depend on the nature of the polycations. Figure 9 Phase-contrast optical microscopy images (×10, ×20, and × 40) of a dispersion of nanostructured wires. The wires are made from 8.3 nm γ-Fe2O3 particles and PEI
at Z = 0.3 (a), Z = 1 (b), and Z = 7 (c). Length distribution of wires was shown in insert. The continuous line was derived from best fit calculation using a log-normal distribution. In order to reveal the microscopic structure of these straight and regular wires, TEM was performed on their dilute dispersions (at concentration 0.01 wt.%). Figure 10 displayed elongated bodies with diameters comprised between 150 and 400 nm of the magnetic wires made of PDADMAC and of PEI. From these figures, we find that the individual particles held together with similar particles densities and formed the elongated core structure. Figure 10 TEM images of wires obtained at Z = 0.3 and
Z PDGFR inhibitor = 7. From our previous work, we concluded that the mechanism of magnetic wires proceeds in two steps: (i) the formation and growth of spherical clusters of particles and (ii) the alignment of the clusters induced by the magnetic dipolar interactions . For the kinetics, the cluster growth and their alignment occurred in parallel, leading to a continuous welding of the cylindrical
PKC inhibitor structure. From the results of clusters shown in Table 4 and Figure 7, we can thus conclude that the magnetic wires made at Z = 0.3 should be positively charged and those at Z = 7 negatively charged. To further confirm it, long (L 0 = 89.4 μm) and positively charged PDADMAC wires were mixed directly with short (L 0 = 19.4 μm) and negatively charged PDADMAC wires. The turbidity of the suspension was increased revealing the formation of larger brush-like aggregates (Figure 11), where the short wires agglutinated onto the larger ones, thanks to attractive electrostatic interactions. Same aggregation between selleck products oppositely charged PEI wires was also evidenced by optic microscopy (see Additional file 1: SI-4). Figure 11 Phase-contrast optical microscopy images (×20). Of a dispersion containing the direct mixing of the rods formed from PDADMAC at Z = 0.3 and Z = 7. The attachment of the short and negatively charged rods (obtained at Z = 7 and green arrows) onto the long and positively charged rods (obtained at Z = 0.3 and blue arrows) confirmed an evident electrostatic attraction.