Keywords : Laser ablation

Biomimetic surfaces with hierarchical structure using microsized texture and nanosized Cu particles for superhydrophobicity

Liguo Qin; Hao Yang; Xinan Feng; Mahshid Hafezi; Mawignon Fagla Jules; Bin Liu; Hui Zhang; Guangneng Dong; Yali Zhang

Advanced Materials Letters, 2019, Volume 10, Issue 8, Pages 569-573
DOI: 10.5185/amlett.2019.2252

Currently, there is a huge demand for the application of superhydrophobic surface in industrial and marine equipment. In this investigation, the hydrophobicity of Q235 steel surface was achieved by implementing micro-patterns on the substrate using laser surface texturing and deposition of nano-copper particles. By controlling the movement of the laser spots, different controlled textures at microscale were fabricated. Via the chelation between the copper species and the catechol moieties on polydopamine (PDA), nano copper was decorated to form the multi-level structure. The surface microstructure, topographies, chemical component and wettability of as-prepared superhydrophobic surface were analyzed systematically. Based on the models built by Wenzel and Cassie–Baxter, the effect of micro texture on contact angle was discussed. This method is expected to have many potential applications including antibacterial materials for the protection of marine equipment. Copyright © VBRI Press.

Liquid-assisted Pulsed Laser Ablation Synthesized Titanium Ferrite Nanoparticles: Structural, Optical And Magnetic Properties

Abhishek Shukla; S.C. Singh; B.K. Pandey; K.N. Uttam; J. Shah; R.K. Kotnala; R. Gopal

Advanced Materials Letters, 2015, Volume 6, Issue 12, Pages 1066-1072
DOI: 10.5185/amlett.2015.5930

Titanium ferrite nanoparticles (NPs) with controlled titanium to iron ratios (Ti/Fe) were synthesized using liquid-assisted pulsed laser ablation (LA-PLA) technique. Present manuscript describes effect of variation of Ti/Fe ratio in the target and the effect of laser pulse energy on size, shape, optical band gap, crystalline phase and magnetic properties of as-synthesized titanium ferrite NPs.  UV-visible absorption, TEM and XRD investigations reveal that size of as-produced NPs decreases with the increase of Ti in the Ti/Fe targets used for ablation. Variation in laser pulse energy at a given Ti/Fe ratio has lesser dependence on size, shape and magnetic properties of produced NPs. Higher ferromagnetism with larger sized particles demonstrates dominance of bulk phenomenon over surface defects for the generation of ferromagnetic responsible spins. As-produced titanium ferrite nanomaterials may be used as promising magnetic recovery catalysts (MRCs).

SERS Studies Of Explosive Molecules With Diverse Copper Nanostructures Fabricated Using Ultrafast Laser Ablation

Hamad Syed; G. Krishna Podagatlapalli; M. A. Mohiddon; Venugopal Rao Soma

Advanced Materials Letters, 2015, Volume 6, Issue 12, Pages 1073-1080
DOI: 10.5185/amlett.2015.6007

We report the fabrication and application of ultra-short pulse laser induced nanostructures (NSs) on copper surface accomplished with different pulse energies and number of pulses. The shapes and sizes of NSs have been evaluated from the field emission scanning electron microscopy (FESEM) data which illustrated different ablation mechanisms in picosecond (ps) and femtosecond (fs) domains. The Cu NSs generated with ps pulses demonstrated Raman enhancements upto ~10 5 -10 8 in the case of the explosive molecules of 1,1-diamino-2,2-dinitroethene (FOX-7), 5 Amino, 3-nitro,1,3,5-nitrozole (ANTA) and 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20). The SERS studies were repeated two more times on the same substrate following a simple cleaning procedure.  We achieved considerable enhancement factors (of >10 5 ) for the Raman modes of an explosive molecule of FOX-7 on fs laser fabricated Cu NSs.

Synthesis And Cytogenetic Effect Of Magnetic Nanoparticles

Bishnu K. Pandey; Ashutosh K. Shahi; Nitisha Srivastava; Girjesh Kumar; Ram Gopal

Advanced Materials Letters, 2015, Volume 6, Issue 11, Pages 954-960
DOI: 10.5185/amlett.2015.5956

In the present study we have successfully synthesized cobalt and cobalt oxide NPs in ethanol and double distilled water respectively. Structural and optical characterizations have been performed by X-ray diffraction and UV-Visible absorption spectroscopy respectively. Magnetic characterization has been performed by vibrating sample magnetometer (VSM). Particle shape and size have been estimated by transmission electron microscopy (TEM). We have studied the effect of cobalt and cobalt oxide NPs on mitotic division of meristamatic roots of Sesbania cannabina. It has been found that cobalt oxide nanoparticles were more toxic than cobalt nanoparticles and both induced various types of chromosomal aberrations in meristamatic root tip cells of sesbania cannabina.