احمد حسين محمد العنتاكي

The fabrication of hybrid protein-Cu3(PO4)2 nanoflowers (NFs) via an intermediate toroidal structure is dramatically accelerated under shear using a vortex fluidic device (VFD), which possesses a rapidly rotating angled tube. As-prepared laccase NFs (LNFs) exhibit ≈1.8-fold increase in catalytic activity compared to free laccase under diffusion control, which is further enhanced by ≈ 2.9-fold for the catalysis under shear in the VFD. A new LNF immobilization platform, LNF@silica incorporated in a VFD tube, was subsequently developed by mixing the LNFs for 15 min with silica hydrogel resulting in gelation along the VFD tube surface. The resulting LNFs@silica coating is highly stable and reusable, which allows a dramatic 16-fold enhancement in catalytic rates relative to LNF@silica inside glass vials. Ultraviolet–visible spectroscopy-based real-time monitoring within the LNFs@silica-coated tube reveals good stability of the coating in continuous flow processing. The results demonstrate the utility of the VFD microfluidic platform, further highlighting its ability to control chemical and enzymatic processes.

Polysulfone (PSF) was prepared under high shear in a vortex fluidic device (VFD) operating in confined mode, and its properties compared with that prepared using batch processing. This involved reacting the pre-prepared disodium salt of bisphenol A (BPA) with a 4,4′-dihalodiphenylsulfone under anhydrous conditions. Scanning electron microscopy (SEM) established that in the thin film microfluidic platform, the PSF particles are sheet-like, for short reaction times, and fibrous for long reaction times, in contrast to spherical like particles for the polymer prepared using the conventional batch synthesis. The operating parameters of the VFD (rotational speed of the glass tube, its tilt angle and temperature) were systematically varied for establishing their effect on the molecular weight (Mw), glass transition temperature (Tg) and decomposition temperature, featuring gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) respectively. The optimal VFD prepared PSF was obtained at 6000 rpm rotational speed, 45° tilt angle and 160 °C, for 1 h of processing with Mw ∼10[thin space (1/6-em)]000 g mol−1, Tg ∼158 °C and decomposition temperature ∼530 °C, which is comparable to the conventionally prepared PSF.

Copper(I) oxide (Cu2O) nanoparticles (NPs) are selectively prepared in high yields under continuous flow in a vortex fluidic device (VFD), involving irradiation of a copper rod using a pulsed laser operating at 1064 nm and 600 mJ. The plasma plume generated inside a glass tube (20 mm O.D.), which is rapidly rotating (7.5 k rpm), reacts with the enclosed air in the microfluidic platform, with then high mass transfer of material into the dynamic thin film of water passing up the tube. The average size of the generated Cu2ONPs is 14 nm, and they are converted to copper(II) oxide (CuO) nanoparticles with an average diameter of 11 nm by heating the as-prepared solution of Cu2ONPs in air at 50 °C for 10 h.

Exfoliation or scrolling of hexagonal boron nitride (h-BN) occurs in a vortex fluidic device (VFD) operating under continuous flow, with a tilt angle of −45° relative to the horizontal position. This new VFD processing strategy is effective in avoiding the build-up of material that occurs when the device is operated using the conventional tilt angle of +45°, where the h-BN precursor and scrolls are centrifugally held against the wall of the tube. At a tilt angle of −45° the downward flow aided by gravity facilitates material exiting the tube with the exfoliation of h-BN and formation of h-BN scrolls then optimized by systematically varying the other VFD operating parameters, including flow rate and rotational speed, along with concentration of h-BN and the choice of solvent. Water was the most effective solvent, which enhances the green chemistry metrics of the processing.

Composites of multi-walled carbon nanotubes (MWCNTs) and superparamagnetic magnetite nanoparticles, Fe3O4@MWCNT, were synthesized in DMF in a vortex fluidic device (VFD). This involved in situ generation of the iron oxide nanoparticles by laser ablation of bulk iron metal at 1064 nm using a pulsed laser, over the dynamic thin film in the microfluidic platform. The overall processing is a three-step in one operation: (i) slicing MWCNTs, (ii) generating the superparamagnetic nanoparticles and (iii) decorating them on the surface of the MWCNTs. The Fe3O4@MWCNT composites were characterized by transmission electron microscopy, scanning transmission electron microscope, TG analysis, X-ray diffraction and X-ray photoelectron spectroscopy. They were used as an active electrode for supercapacitor measurements, establishing high gravimetric and areal capacitances of 834 F g−1 and 1317.7 mF cm−2 at a scan rate of 10 mV s−1, respectively, which are higher values than those reported using similar materials. In addition, the designer material has a significantly higher specific energy of 115.84 W h kg−1 at a specific power of 2085 W kg−1, thereby showing promise for the material in next-generation energy storage devices

Hexagonal boron nitride (h-BN) is rendered magnetically responsive in aqueous media by binding superparamagnetic magnetite nanoparticles 8.5–18.5 nm in diameter on the surface. The composite material was generated under continuous flow in water in a dynamic thin film in a vortex fluidic device (VFD) with the source of iron generated by laser ablation of a pure iron metal target in the air above the liquid using a Nd:YAG pulsed laser operating at 1064 nm and 360 mJ. Optimum operating parameters of the VFD were a rotational speed of 7.5k rpm for the 20 mm OD (17.5 mm ID) borosilicate glass tube inclined at 45 degrees, with a h-BN concentration at 0.1 mg mL−1, delivered at 1.0 mL min−1 using a magnetically stirred syringe to keep the h-BN uniformly dispersed in water prior to injection into the base of the rapidly rotating tube. The resulting composite material, containing 5.75% weight of iron, exhibited high phosphate ion adsorption capacity, up to 171.2 mg PO43− per gram Fe, which was preserved on recycling the material five times.

Selective formation of only one iron oxide phase is a major challenge in conventional laser ablation process, as is scaling up the process. Herein, superparamagnetic single-phase magnetite nanoparticles of hexagonal and spheroidal-shape, with an average size of ca. 15 nm, are generated by laser ablation of bulk iron metal at 1064 nm in a vortex fluidic device (VFD). This is a one-step continuous flow process, in air at ambient pressure, with in situ uptake of the nanoparticles in the dynamic thin film of water in the VFD. The process minimizes the generation of waste by avoiding the need for any chemicals or surfactants and avoids timeconsuming purification steps in reducing any negative impact of the processing on the environment.

Macroporous bovine serum albumin (BSA) nanoparticles with controllable diameter were readily fabricated in a rapidly rotating angled glass tube in a vortex fluidic device (VFD). Systematically varying the rotational speed and the ratio of BSA, ethanol, and glutaraldehyde led to conditions for generating ca. 600 nm diameter macroporous particles that have intrinsic fluorescence emission at 520 nm when excited at 490 nm. The presence of the macropores increased the absorption efficiency of rhodamine B with potential applications for drug delivery purpose, compared with BSA nanoparticles having surfaces devoid of pores. Further control over the size of BSA nanoparticles occurred in the presence of C-phycocyanin protein during the VFD processing, along with control of their shape, from spheres to pockets, as established in exploring the parameter space of the microfluidic device.

Carbon nanodots (CDs) with size dependent fluorescence are synthesized from multi-walled carbon nanotubes (MWCNTs) under continuous flow in a vortex fluidic device (VFD) when irradiated by a pulsed laser with a wavelength of 1064 nm, without subsequent passivation procedures. The CDs have a relatively narrow size distribution averaging ca. 6 nm in diameter, and have low cytotoxicity and high colloidal stability with the highest emission intensity of the solution at 450 nm under a 345 nm excitation wavelength. Further downstream processing on the as-processed CDs revealed tunability of the emission from 450 nm to 325 nm.

In general, fluorescent polyethylenimine (PEI) nanoparticles absorb primarily UV light, with the fluorophores typically having extended conjugated structures. In this work, PEI nanoparticles of circa 10 nm in diameter, devoid of such structural features and with tunable fluorescence, were generated in a microfluidic platform. Tunability of the fluorescence was achieved by varying the flow rate of liquid entering the rapidly rotating tube in a vortex fluidic device (VFD), without the need for additional reagents. Chemical incorporation of amide functional groups triggered enhanced fluorescence intensity and auto-fluorescence over a wide range, and the resulting nanoparticles showed significantly reduced cytotoxicity compared to as-received polymers.

new Fe(III), Co(III) metal complexes were synthesize with aryl azo 4,4'-Bis( 3- hydroxy phenol azo )- Otolidine [BHPAT] derived from O-tolidine and resorcinol. The ligand and it’s complexes were characterized by H1NMR, FTIR, UV-Vis. spectra and conductivity measurements, The ligand behaves as bidentate (N,O) of the ligand forming chelates with (2:1) (metal:ligand). The molar conductance values of the Fe(III) and Co(III) complexes of the bidentate ligand indicate their nonionic character, Octahedral environment is suggested for metal complexes.

The new ligand of (1,2-diphenylethane-1,2-diylidene-bis(hydrazine-2,1-iylidene))bis (methan-1-yl-1-ylidene)diphenol (DEDHIMD)، has been prepared by reacting Salicyladehyde with Benzil dihydrazone (prepared from benzil with hydrazine in ethanol) in ethanol. This Ligand has been Identified by Using 1HNMR، UV-Vis.& FTIR Spectra. We have also prepared chelate complex by reacting this ligand with metal ions VO(IV) and Cu(II).The preparation has been conducted after fixing the optimum conditions of concentration. U.V-Vis. spectra of the complexes solution of the above metal ions with the ligand (DEDHIMD) have been studied for a range of concentrations which obey Lampert-Beers Law. The structure of complex are deduced according to mole ratio method which was obtained from the spectroscopic studies of the complex solution. The ratio of metal: ligand obtained is (1:1) to the complexes ions. The (UV -Vis) absorption spectrum of complex in ethanol solution showed chromic shift، as compared with that of free ligand. The infrared spectra of the chelating complex have been studied، they were also compared with the ligand spectrum، they showed obvious changes in the band positions، some of them has been disappeared while others are shifted، this may indicate that a coordination between the metal ions and our ligand takes place. The conductivity measurements of our complexes have not shown that ionic character. Depending on these results، in addition to the measurements of magnetic susceptibility of our complexes it seems of these complexes are paramagnetic. We can conclude that the proposed geometrical structures of the complexes of VO(IV) and Cu(II) ions are octahedral. The determination of the biological activity of complexes were carried out on Pseudomonas averuginose, Serratia fonticola and Staphylococcus aureus bacteria.

Preparation and Characterization of complexes of Fe(lll) ion with the new ligand (1,2-diphenyl-N,N'-bis(2-hydroxybenzohydrazide)) ethan -1,2-diimine (DBHBED).