Driven by functionality and purity demand for applications of inorganic nanoparticle colloids in optics, biology, and energy, their surface chemistry has become a topic of intensive research interest. Consequently, ligand-free colloids are ideal reference materials for evaluating the effects of surface adsorbates from the initial state for application-oriented nanointegration purposes. After two decades of development, laser synthesis and processing of colloids (LSPC) has emerged as a convenient and scalable technique for the synthesis of ligand-free nanomaterials in sealed environments. In addition to the high-purity surface of LSPC-generated nanoparticles, other strengths of LSPC include its high throughput, convenience for preparing alloys or series of doped nanomaterials, and its continuous operation mode, suitable for downstream processing. Unscreened surface charge of LSPC-synthesized colloids is the key to achieving colloidal stability and high affinity to biomolecules as well as support materials,...

Laser Synthesis and Processing of Colloids: Fundamentals and Applications

A ligand based innovative composite material for selective lead(II) capturing from wastewater

Innovative composite material for efficient and highly selective Pb(II) ion capturing from wastewater

Novel conjugated hybrid material for efficient lead(II) capturing from contaminated wastewater.

Laser-assisted synthesis, reduction and micro-patterning of graphene: Recent progress and applications

Complex relationship between alumina and selenium-doped carbonated hydroxyapatite as the ceramic additives to electrospun polycaprolactone scaffolds for tissue engineering applications

Carbonated hydroxyapatite (CHAP)-doped with different concentrations of gold (Au) was sputtered on a scaffold of alumina via pulsed laser deposition technique The structural, microstructural and morphological behaviors were investigated FESEM indicated that Au-CHAP was formed as spherical shapes with diameters around 025–045 μm, while alumina was formed in rectangular grains with dimensions around 09 × 13 × 225 μm3 The examination of mechanical properties indicated that micro-hardness has been enhanced with a variation of sputtering composition upon changing of Au concentration It was enhanced form 310 GPa at zero contribution of Au to be 340 GPa at the highest one Moreover, the cell viability and cells were grown on the scaffold surface were also examined against the HFB4 cell line It was shown that scaffold compositions displayed high compatibility and reached 925 ± 47% Furthermore, the cells were not only spread and grew on the scaffold's surface, but they also proliferated deeply through the porosity of the scaffold as a function of Au dopant This implies that tailoring scaffold for biomedical engineering depends on superfine composition could be suggested for numerous applications

Au-doped carbonated hydroxyapatite sputtered on alumina scaffolds via pulsed laser deposition for biomedical applications

Calcium phosphates (CPs) are excellent sorbents, with hydroxyapatite being the most commonly used for heavy metal removal from ecological samples. The use of more acidic brushite as a CP sorbent can be justified by its greater pH compatibility with particular types of soil, such as soil in the areas of high rainfall, but also iron-containing soil prone to oxidative weathering and soil nitrified with ammonium fertilizers. Here, brushite nanoparticles were supplemented with vivianite as another metal phosphate phase and the resulting material was studied at different concentrations of the respective phases (x = 0.0, 0.2, 0.4, 0.8 and 1.0 in FexCa1−xHPO4·2H2O). Structural refinement showed that the weight ratio between the two phases intensely impacted their crystallographic ordering. The modeling of thermal analysis data with the use of Coats-Redfern and Horowitz–Metzger formalisms showed a multifold reduction in the activation energy and in the changes of enthalpy and entropy for both dehydration and decomposition transitions with the introduction of vivanite to brushite. Increasing the vivianite content enhanced the efficacy of the removal of heavy metals from aqueous solutions, but only up to a certain limit. The maximal efficacy, along with hardness and microporosity, was obtained for the x=0.8 composition. For this composition, over 98 % of Pb(II) and 85 % of Cr(VI) were removed from the solution at the standard heavy metal concentrations of 2 ppm. The systematic analysis at different weight ratios between the two constitutive phases allowed for the delineation of a composition with ideal properties for environmental decontamination applications.

Tuning the composition of new brushite/vivianite mixed systems for superior heavy metal removal efficiency from contaminated waters

The generation of nanoparticles using pulsed laser ablation has inherent advantages compared to conventional methods, like the purity and stability of the fabricated nanoparticles, aerosols and colloids. This study addresses the influence of laser parameters such as laser fluence, laser wavelength as well as focusing condition of laser beam on the size and morphology of the gold nanoparticles prepared in de-ionized water by pulsed laser ablation. The optimum conditions at which gold nanoparticles are obtained with controllable average size have been reported as these parameters affected the size, distribution and absorbance spectrum. The effect of laser fluence was studied. The laser fluences were divided into three regions (low, middle and high). A noteworthy change was observed at each region. At low fluences, the size of the nanoparticles decreases as the fluence increases to a certain critical value after which the size of the nanoparticles increases as the fluence increases. Also a significant change in the size distribution of the gold nanoparticles was noticed during the variation of the focusing conditions at gold–water interface.

Effect of focusing conditions and laser parameters on the fabrication of gold nanoparticles via laser ablation in liquid

The purpose of this work to find the effect of magnetic material on adsorption of heavy metal cations (Cr6+, Cd2+ and Cu2+). Consequently, hexagonal cobalt ferrite (CoFe2O4) was prepared simply by flash method followed by calcination. The prepared sample was characterized using X-ray diffraction and FTIR which revealed the structure of nanoferrite. Field emission scanning electron microscopy and EDX explore the hexagonal-shaped product. The obtained results from surface area analysis (BET) showed that cobalt ferrite has large surface area (71.564 m2/g). The magnetic properties were studied by VSM and Faraday’s method from which the sample acts as ferromagnetic material with large value of saturation magnetization (66.380 emu/g). Electrical properties such as conductivity and activation energy were studied using LCR bridge; the data confirmed semiconductor behavior of sample. The sample under investigation exhibited very good adsorption efficiency for heavy metal cation (Cr6+, Cd2+ and Cu2+) from wastewater. The maximum adsorption appeared for Cd6+ at pH 6 and contact time 8 h.

Rania Ramadan

Papers

Complex relationship between alumina and selenium-doped carbonated hydroxyapatite as the ceramic additives to electrospun polycaprolactone scaffolds for tissue engineering applications

Au-doped carbonated hydroxyapatite sputtered on alumina scaffolds via pulsed laser deposition for biomedical applications

Tuning the composition of new brushite/vivianite mixed systems for superior heavy metal removal efficiency from contaminated waters

Effect of focusing conditions and laser parameters on the fabrication of gold nanoparticles via laser ablation in liquid

Physical study of cobalt ferrite and its application in purification of water