Коллоидный журнал

This study investigates the synthesis and characterization of titanium dioxide/graphene oxide (TiO₂/GO) nanocomposites for their potential application in photocatalytic dye degradation. Titanium dioxide nanoparticles were synthesized via chemical co-precipitation, while graphene oxide was prepared using a modified Hummer’s method. TiO₂/GO nanocomposites with graphene oxide concentrations of 1.5 wt.% and 3 wt.% were fabricated by ultrasonification of distilled water solution of synthesized materials in respective ratios. The prepared samples were subjected to structural, optical, electronic, morphological, and functional group analyses. Results revealed that the TiO₂/GO (3 wt.%) nanocomposite exhibited the lowest optical bandgap of 3.13 eV compared to 3.28 and 3.24 eV of pure and 1.5 wt.% TiO₂/GO, respectively. TiO₂/GO (3 wt.%) also exhibited reduced photoluminescence intensity, indicative of enhanced photocatalytic activity. Under sunlight irradiation, the TiO₂/GO (3 wt.%) nanocomposite achieved an 81.91% degradation efficiency of Brilliant Blue R dye. This is a huge improvement, comparing this to the 65.26 and 77.04 % of pure and 1.5 wt.% TiO₂/GO composite, respectively. This study highlights the promising potential of TiO₂/GO nanocomposites as efficient photocatalysts for environmental remediation applications.

Potential interactions between cetyltrimethylammonium bromide (CTAB) and chlorpheniramine maleate (CPM) drug were explored in aqueous as well as aqueous K-salts (KCl, KHSO₄, and K₂CO₃) media by using the conductivity measurement technique. Single critical micelle concentration (CMC) was determined during the association of CTAB/CPMmixtures in aqueous and aqueous K-salts media. The values of CMC showed an increasing trend with the rise in experimental temperatures from 298.15 K to 323.15 K. CMC of CTAB in aqueous CPM drug solution decreased compared to those observed in pure CTAB aqueous medium. The values of CMC determined in all CTAB/CPMmixtures with different K-salt media exhibited a decreasing trend in comparison to those obtained from the aqueous CTAB/CPMmixtures. Micelles formation was found to occur at lower amphiphile concentrations in the presence of various K-salts media. The standard free energy changes (∆Gmo ) were negative, suggesting the spontaneous aggregation of the components present within the CTAB/CPMmixtures. Assessment of standard enthalpy changes ( ∆Hmo ) and entropy changes (∆Smo ) revealed the electrostatic and hydrophobic interactions between CTAB and CPM species in different potassium salts media. Various other significant thermodynamic parameters, including transfer properties (∆Gm, tro , ∆Hm, tro , ∆Sm, tro ), molar heat capacity (∆Cm, po ), intrinsic enthalpy gain (∆Hmo,* ) and compensation temperature (T_c) were examined and evaluated for the CTAB/CPMmixtures in different experimental media, and the results were interpreted accordingly. These interesting results provide significant information on the surfactant-drug interactions in different potassium salts media, which will be highly useful for future research in developing the formulation procedures of various drugs and related pharmaceutical excipients.

Today, microfluidics has emerged as a revolutionary interdisciplinary topic garnering substantial attention in a wide range of biotechnology and biochemical applications. In this research work, a numerical investigation of a microfluidic micromixer is carried out using finite element method. This ring-shaped micromixer based on electroosmosis phenomena has been developed to mix two different fluids. For enhanced efficiency of this mixing system, a sinusoidal electric potential is systematically introduced between the electrodes with a peak value of 0.1 V and an operational frequency of 8 hertz. The efficiency of the micromixer is increased by designing the semi-circular obstacles within the micromixer. The simulation results based on this setup indicate that the micromixer has a very high efficiency of mixing to the extent of a commendable 98%, thus highlighting its vast potential for beneficial applications in a wide range of fields in association with microfluidics, biochemistry, and biomedical sciences. The effect of manipulating the input frequency and potential on the electrodes on the efficiency of mixing has been explored systematically and the findings presented accordingly.

Cancer is amongst the leading causes of mortality worldwide. Separation of circulating tumor cells has been under the spotlight in many studies due to its critical role played in cancer's diagnosis, prognosis, and treatment. Microfuidic channels have been instrumental in the separation of target analytes like circulating tumor cells, components of blood, etc., in many biochemical diagnostic processes. Electrokinetic-based cell separation of biological entities like blood components and circulating tumor cells is one of the significant research areas in the past decade. In the current work, dielectrophoresis (DEP) microfluidic devices using sawtooth electrodes under low voltage of about 1 V has been proposed with the target of separating Ht-29 CTCs from white blood cells (WBCs). In a computational study, electric potential profile, velocity field profile within the microchannel, cell particle trajectories across the channel, and the DEP force imposed upon the cells were analyzed using the finite element method simulation. The effect of changing the velocity of cells and changing the height of electrodes on the separation efficacy was analyzed and the results were demonstrated.