Fabrication of TiO2-Nanotube-Array-Based Supercapacitors

In this work, a simple and cost-effective electrochemical anodization technique was adopted to rapidly grow TiO₂ nanotube arrays on a Ti current collector and to utilize the synthesized materials as potential electrodes for supercapacitors. To accelerate the growth of the TiO₂ nanotube arrays, lactic acid was used as an electrolyte additive. The as-prepared TiO₂ nanotube arrays with a high aspect ratio were strongly adhered to the Ti substrate. X-ray diffraction (XRD) and transmission electron microscopy (TEM) results confirmed that the TiO₂ nanotube arrays were crystallized in the anatase phase. TEM images confirmed the nanotublar-like morphology of the TiO₂ nanotubes, which had a tube length and a diameter of ~16 and ~80 nm, respectively. The electrochemical performance of the TiO₂ nanotube array electrodes was evaluated using the cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge (GCD) measurements. Excellent electrochemical response was observed for the electrodes based on the TiO₂ nanotube arrays, as the cells delivered a high specific capacitance of 5.12 mF/cm² at a scan rate of 100 mV/s and a current density of 100 μA/cm². The initial capacity was maintained for more than 250 cycles. Further, a remarkable rate capability response was observed, as the cell retained 88% of the initial areal capacitance when the scan rate was increased from 10 to 500 mV/s. The results suggest the suitability of TiO₂ nanotube arrays as electrode materials for commercial supercapacitor applications

Novel Magnetite (Fe₃O₄)-Methylcellulose Nanocomposites Synthesized Using the Reverse Co-Precipitation Approach

A simple approach was used to create Fe3O4-methylcellulose (MC) nanocomposites, which were then analyzed using XRD, FTIR, and FE-SEM to determine their structure. The effective factors for enhancing the ratio of magnetite NPs in the samples were investigated using RTFM and optical absorbance. Fe3O4 was synthesized utilizing the reverse co-precipitation technique and magnetic characteristics. Fe3O4/MC nanocomposites with magnetite/MC weight ratios of 0, 0.07, 0.15, and 0.25 have been developed. The diffraction pattern of magnetite is well indexed in accordance with the spinal reference pattern of Fe3O4 (space group: R¯3m), as confirmed by the Rietveld analysis of XRD data of magnetite NPs with an average crystallite size of 50 nm. Magnetite’s insertion into the MC network causes a red shift in the band gap energy (Eg) as the weight percentage of magnetite nanoparticles in the samples rises. The MC, MC-7, MC-15, and MC-25 samples have Eg values of 5.51, 5.05, 2.84, and 2.20 eV, respectively

Optically functionalized hierarchical hematite assembled silica-titania nanocomposites for hydrocarbon detection: fiber optic chemical sensor

Mesoporous hematite nanoparticles (HNPs) encapsulated SiO2–TiO2 nanocomposites (STNC) are synthesized and heat-treated at low-temperature 50 °C for 1h (STNC/1h) and 2h (STNC/2h) by sol-gel process for hydrocarbons chemical sensing. Microscopic analysis revealed the thermally stable hierarchical structure of HNPs, which changed into aggregated porous spherical morphology after encapsulation in STNC and heat treatment. The low surface area of HNPs ~55 m2/g which is increased up to 289 m2/g for H-STNC/2h, is advantageous to enhance sensing device activity. Magnetic properties exhibited the superparamagnetic behavior of H-STNC/2h. The H-STNC/2h coated fiber optic chemical sensor revealed a linear response towards the higher carbon chains, sensitivity is calculated as 5.3 counts per unit variations in the carbon chain at 515 nm with R2 ~ 0.98. The proposed magnetic sensing device has good reversibility, stability, and validity without any leaching traces

Dielectric Properties of Bi_2/3Cu₃Ti₄O₁₂ Ceramics Prepared by Mechanical Ball Milling and Low Temperature Conventional Sintering

In the current study, Bi2/3Cu3Ti4O12 (BCTO) ceramics were prepared by mechanical ball mill of the elemental oxides followed by conventional sintering of the powder without any pre-sintering heat treatments. The sintering temperature was in the range 950–990 °C, which is 100–150 °C lower than the previous conventional sintering studies on BCTO ceramics. All the ceramic samples showed body-centered cubic phase and grain size ≈ 2–6 μm. Sintering temperature in the range 950–975 °C resulted in comparatively lower dielectric loss and lower thermal coefficient of permittivity in the temperature range from −50 to 120 °C. All the BCTO ceramics showed reasonably high relative permittivity. The behavior of BCTO ceramics was correlated with the change in oxygen content in the samples with sintering temperature. This interpretation was supported by the measurements of the energy dispersive x-ray spectroscopy (EDS) elemental analysis and activation energy for conduction and for relaxation in the ceramics

Impact of molar teeth distalization by clear aligners on temporomandibular joint: a three-dimensional study

Abstract Background Maxillary molar distalization is a common technique used in the non-extraction treatment of Angle Class II malocclusion that can effectively correct the molar relationship and create spaces for anterior teeth alignment. However, this approach may also impact the temporomandibular joint (TMJ) due to predictable changes in the posterior vertical dimension. Despite its widespread use, Class II malocclusions correction by molar distalization with clear aligners has not been investigated for their effects on the TMJ. Therefore, this study aimed to analyze the impact of sequential molar distalization using clear aligners on the TMJ. Methods Three-dimensional CBCT scans of 23 non-growing patients (7 males, 16 females; mean age 29.8 ± 4.6 years) with skeletal class I or II malocclusion and a bilateral molar class II relationship treated by sequential upper molars distalization with orthodontic clear aligners (Invisalign, Align Technology, San Josè, Ca, USA). A total of 46 joints were examined before and after molar distalization using Anatomage InvivoDental 6.0.3. Linear and angular measurements of the mandibular joint were measured, including joint parameters, inclination, position, and the dimension of the condyle and articular fossa. In addition, 3D volumetric spaces of the joint were analyzed. All data were statistically analyzed by paired T test to determine the differences between the pre-and post-orthodontic procedures. Results No statistically significant differences were found in all primary effects resulting from maxillary molars distalization by clear aligners on TMJ components measurements and joint spaces between T0 and T1. Meanwhile, statistically significant differences were observed in the linear position of the upper molars and the molar relationship parameter with at least P ≤ 0.05. Conclusion Treatment by sequential upper molars distalization with clear aligners does not lead to significant TMJ parameters changes in condyle and fossa spaces, dimensions, and positions