The effect of length variation on the magnetic properties of NiFe alloy NANOWIRES electrodeposited into the alumina template was investigated. The diameter (45±2.5 nm) and length (~1.9, 7.12, 8.3, 9.5 and 13.3mm) of the NANOWIRES were estimated from scanning electron microscopy images. Energy dispersive spectroscopy results showed Ni3Fe7 composition of the alloy NANOWIRES. The magnetic properties of the samples were investigated by vibrating sample magnetometer. It showed that with increasing the length of the NANOWIRES from 1.9±0.1mm to 13.3±0.66mm, coercivity reduced from 1050 Oe to 705 Oe and squareness reduced from 0.64 to 0.46. The results proved increasing the magnetostatic interaction between the NANOWIRES with length. Progress toward the multi-domain behavior was predicted caused to drastically reduce in the coercivity.

We briefly reviewed the existing research on the ecotoxicity of NANOWIRES and suggested directions for further study. NANOWIRES are technological innovations that can benefit humans. However, it is important to consider the effects of NANOWIRES on the environment. Only a few studies have reported acute and chronic ecological toxicity of NANOWIRES on aquatic and terrestrial organisms, and limited research papers have reported antibacterial effects of NANOWIRES. It is assumed that NANOWIRES have a toxic mechanism similar to that of nanoparticles or ions, but the mechanism remains unknown because so little research has been conducted on the ecological toxicity of NANOWIRES. More in-depth assessments of the chronic toxicity, bioavailability, cytotoxicity, and genotoxicity of NANOWIRES on various species are needed.

The transport properties of oligo(ethyne) dithiolates coupled with gold electrodes is calculated using the non-equilibrium Green’s functions technique. The effect of molecular wire length on current-voltage characteristics for (-C≡C-)n n = 1-5 is investigated. The calculated decay coefficient at low bias voltage is (0.025 ± 0.002 Ǻ-1) which is found to be lower than that of alkanthiols. Results reveal that the HOMO-LUMO gap of the oligo(ethyne)s are correlated to the reciprocal of the number of triple bonds.