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A supramolecular Cd( <scp>ii</scp> )-metallogel: an efficient semiconductive electronic device
摘要： A sonication-based strategy for the synthesis of a functional supramolecular Cd(II)-metallogel (CdA-OX) has been achieved through mixing cadmium(II) acetate dihydrate and oxalic acid dihydrate, a low molecular weight gelator (LMWG), in N,N-dimethyl formamide solvent at room temperature under atmospheric pressure. The mechanical properties of the supramolecular Cd(II)-metallogel were investigated through a rheological study. The pebble-like self-assembly hierarchical architecture of the supramolecular metallohydrogel was visualized through field emission scanning electron microscopy investigations. The electrical properties of the metallogel were thoroughly examined and indicate its semiconducting nature. Based on its conducting properties, the Cd(II)-metallogel was successfully applied to a Schottky barrier diode. Overall, this work is a novel instance of technologically challenging electronic device application of a Cd(II)-metallogel.
关键词： Schottky barrier diode,supramolecular Cd(II)-metallogel,sonication-based synthesis,electronic device,semiconducting nature
更新于2025-11-21 11:18:25
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Use of near infrared spectroscopy and chemometrics to evaluate the shelf-life of cloudy sonicated apple juice
摘要： Fresh products, such as cloudy apple juice, could be preserved from early spoilage through the application of non-thermal processes such as sonication. However, shelf-life analyses based on microbiological and sensory evaluations are expensive and time consuming. Few studies have applied near infrared spectroscopy to evaluate the quality and decay of apple juices. Here, a feasibility trial was conducted to study the spectral behaviour at 1300–2500 nm combined with chemometric approaches. The shelf-life was monitored during two experiments, a challenge test with juices inoculated with spoilage yeasts (inoculated non-sonicated (INS)) and then submitted to sonication treatments (inoculated sonicated (IS)), and a storage test to evaluate the spoilage on non-inoculated juices (non-inoculated non-sonicated (NINS)) and sonicated non-inoculated juices (non-inoculated sonicated (NIS)). These experiments were investigated at six different refrigeration times 7, 14, 21, 28 and 60 days. Two functions were modelled to describe the behaviours of the first principal component according to the storage time. In agreement with a previous chemical and sensory evaluation, this approach allowed us to highlight shelf-life end points of 7 and 14 days for non-sonicated and sonicated samples, respectively. Three different models were evaluated for classification purposes: (1) sonicated versus non-treated samples, (2) end-point shelf-life evaluation at seven days for the NINS and INS juices and (3) end-point shelf-life discrimination at 14 days for IS and NIS samples. A partial least square-discriminant analysis enabled a group classification with accuracy values ranging from 0.63 to 1.00. The application of a variable importance in projection index to interpret the wavelengths of the spectral features suggests a contribution of organic acids and lipids to the prediction of decay. A canonical discriminant analysis provided a clearer separation of samples according to the storage time, especially in relation to the two time thresholds of 7 and 14 days.
关键词： Apple juice,spoilage,near infrared spectroscopy,shelf-life,sonication
更新于2025-09-23 15:23:52
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Tuning charge transfer at the electron donor/acceptor assembly through vibration-induced aggregation of P3HT chains in solution
摘要： In this report, we developed a test platform to probe charge transfer at a model electron donor/acceptor system in which charge transfer rate is investigated through electrical contact resistance in a metal oxide/organic semiconductor/metal oxide structure using transmission line method (TLM). Aluminum (Al)-doped zinc oxide (AZO) films were adopted as source and drain electrodes. Molecular ordering of the organic semiconductor was systematically varied through vibration-induced aggregation (VIA) treatment of poly(3-hexylthiophene) (P3HT) polymer chains in solution to probe the effect of molecular ordering of P3HT (donor) in contact with AZO (acceptor) on interfacial charge transfer at the electron donor (P3HT)/acceptor (AZO) interface crucial in determining device performance of optoelectronic devices. Enhanced charge transfer at the donor/acceptor interface containing P3HT film treated with VIA process was demonstrated by reduction of the contact resistance via TLM. More efficient charge transfer at the AZO/sonicated-P3HT/AZO compared with AZO/pristine-P3HT/AZO results from enhanced charge carrier mobility of P3HT near the interface, blocking back-transfer of injected holes from P3HT to the AZO electrode, as demonstrated by theoretical prediction. Effect of VIA treatment on charge transfer at the electron donor/acceptor interface is confirmed through comparing the AZO/P3HT contact resistance depending on the degree of VIA for P3HT polymer chains by varying sonication time. Our work presented here demonstrates that improvement in structural arrangement of polymer chains leads to efficient charge transfer at interface.
关键词： Sonication,Charge transfer,p3ht
更新于2025-09-23 15:23:52
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Graphite to Graphene: Green Synthesis Using Opuntia ficus-indica
摘要： Green synthesis promotes partial or total substitution of chemicals that are potentially harmful to the environment with more friendly ones and is also concerned with decreasing energy consumption. In this study, commercial graphite (1.0 g) was mixed with Opuntia ficus-indica (Ofi) (1.0 ml) and 50 ml deionized water in a glass beaker. The mixture was sonicated in an ultrasonic bath for 30 min at room temperature. Subsequently, the supernatant was transferred to a glass substrate and dried. To characterize the graphitic nanostructure, we used Raman spectroscopy, x-ray diffraction (XRD) analysis, x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and transmission electron microscopy (TEM). Raman spectroscopy was used to characterize the crystal structure. The ratio of the relative intensity of the G and 2D peaks in the Raman spectrum followed by deconvolution of the 2D band suggested that four and five layers of graphene were formed. The XRD profile showed a strong decrease in the (002) peak intensity with a thickness of 0.34 nm characterizing the graphite structure. The C:O ratio measured by XPS showed a degree of oxidation comparable to reports on few-layer graphene (FLG), and AFM images showing the roughness of the sheets revealed small steps of 1 nm with length of about 100 nm. Structural and morphological properties were analyzed by TEM. We found thin graphene layers of about one micron in extent; at 10-nm scale, structures of two, three, four, and five layers were identified. These results suggest that this method can be used for synthesis of FLG via an environmentally friendly route without use of acids or strong chemical oxidants.
关键词： few-layer graphene,sonication,Opuntia ficus-indica,Green synthesis
更新于2025-09-19 17:15:36
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Raman spectroscopic analysis of high molecular weight proteins in solution – considerations for sample analysis and data pre-processing
摘要： This study explores the potential of Raman spectroscopy, coupled with multivariate regression techniques and a protein separation technique (ion exchange chromatography), to quantitatively monitor diagnostically relevant changes in high molecular weight proteins in liquid plasma. Measurement protocols to detect the imbalances in plasma proteins as an indicator of various diseases using Raman spectroscopy are optimised, such that strategic clinical applications for early stage disease diagnostics can be evaluated. In a simulated plasma protein mixture, concentrations of two proteins of identified diagnostic potential (albumin and fibrinogen) were systematically varied within physiologically relevant ranges. Scattering from the poorly soluble fibrinogen fraction is identified as a significant impediment to the accuracy of measurement of mixed proteins in solution, although careful consideration of pre-processing methods allows construction of an accurate multivariate regression prediction model for detecting subtle changes in the protein concentration. Furthermore, ion exchange chromatography is utilised to separate fibrinogen from the rest of the proteins and mild sonication is used to improve the dispersion and therefore quality of the prediction. The proposed approach can be expeditiously employed for early detection of pathological disorders associated with high or low plasma/serum proteins.
关键词： sonication,pre-processing,disease diagnostics,Raman spectroscopy,plasma proteins,ion exchange chromatography,multivariate regression
更新于2025-09-19 17:15:36
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Simple preparation of graphene quantum dots with controllable surface states from graphite
摘要： Graphite is economic and earth-abundant carbon precursor for preparing graphene quantum dots (GQDs). Here, we report a facile and green approach to produce GQDs from graphite flakes via a pulsed laser ablation (PLA) method assisted by high-power sonication. A homogeneous dispersion of graphite flakes, caused by high-power sonication during PLA, leads to the formation of GQDs following a laser fragmentation in liquid (LFL) rather than laser ablation in liquid (LAL) mechanism. The final product of GQDs exhibits the distinct structural, chemical, and optical properties of pristine graphene itself. However, graphene oxide quantum dots (GOQDs) with abundant surface oxygen-rich functional groups are readily formed from graphite flakes when high-power sonication is not employed during the PLA process. GQDs and GOQDs show a significantly different luminescence nature. Hence, selective production of either functional GQDs or GOQDs can be achieved by simply turning the high-power sonication during the PLA process on and off. We believe that our modified PLA process proposed in this work will further open up facile and simple routes for designing functional carbon materials.
关键词： high-power sonication,graphene quantum dots,luminescence,pulsed laser ablation,graphite flakes
更新于2025-09-16 10:30:52
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Sonication-Enhanced Alignment Relay Technique for the Orientation of Single-Walled Carbon Nanotubes
摘要： The high demand for thin, lightweight yet fast and e?cient devices is a driving force behind the miniaturization trend in the electronics industry. Speci?cally, the advancement of semiconducting single-walled carbon nanotubes (SWNTs) can continue to revolutionize transistors, although there are still many challenges ahead. We have previously reported an alignment relay technique (ART) that is capable of simultaneously controlling the alignment, length, and diameter of surface deposited SWNTs. However, the current technique yields inconsistencies in orientation, lengths of tubes, and their density. Here, we present a reviewed ART protocol that includes sonication for improved selectivity. We show that the SWNTs average alignment increased from 40% to 77% within a 10° range in orientation with sonication times as low as 5 min. Sonication generated larger diameter nanotubes on the surface, with a preference for semiconducting chiral tubes in the range of 1.44?1.61 nm in diameter. Consequently, simple alterations to the standard alignment relay technique can prove to be prosperous in improving selectivity and orientational control of single-walled carbon nanotubes. This work has direct impact for the simultaneous control of nanotube alignment and nanotube chiralities.
关键词： alignment relay technique,iptycenes,alignment,sonication,single-walled carbon nanotubes,surface chemistry,liquid crystals
更新于2025-09-16 10:30:52
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Fluorescent Metal-Doped Carbon Dots for Neuronal Manipulations
摘要： There is a growing need for biocompatible nanocomposites that may efficiently interact with biological tissues through multiple modalities. Carbon dots (CDs) could serve as biocompatible fluorescence nanomaterials for targeted tissue/cell imaging. Important goals toward this end are to enhance the fluorescence quantum yields of the CDs and to increase their targetability to cells. Here, sonochemistry was used to develop a one-pot synthesis of CDs, including metal-doped CDs (M@CDs), demonstrating how various experimental parameters, such as sonication time, temperature, and power of sonication affect the size of the CDs (2–10 nm) and their fluorescence properties. The highest measured quantum yield of emission was ~16%. Similarly, we synthesized CDs doped with different metals (M@CDs) including Ga, Sn, Zn, Ag, and Au. The interaction of M@CDs with neuron-like cells was examined and showed efficient uptake and low cytotoxicity. Moreover, the influence of the M@CDs on the improvement of neurites during initiation and elongation growth phases were compared with pristine CDs. Our research demonstrates the use of M@CDs for imaging and for neuronal interactions. The M@CD nanocomposites are promising due to their biocompatibility, photo-stability and potential selective affinity, paving the way for multifunctional biomedical applications.
关键词： sonication,neurite outgrowth,biocompatibility,metal-doped carbon dots,neural tissue engineering,fluorescence
更新于2025-09-09 09:28:46
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Cooperative effect between BaTiO3 and CaFe2O4 in a cocatalyst-free heterojunction composite for improved photochemical H2 generation
摘要： A series of novel BaTiO3/CaFe2O4 heterojunction composites with different weight ratios of CaFe2O4 vs BaTiO3 was successfully fabricated by sonication-calcination method using the pre-prepared BaTiO3 and CaFe2O4 powders synthesized in hydrothermal and sol-gel methods, respectively. The composites were well characterized using XRD, UVevis DRS, SEM, TEM, EDS and XPS to substantiate that BaTiO3 and CaFe2O4 coexist in the heterojunction composite. The highest photocatalytic hydrogen generation rate was obtained for BaTiO3/CaFe2O4 (40 wt%) compared to either of its individual counterparts and this improvement indicated the existence of a cooperative effect between BaTiO3 and CaFe2O4 in the heterojunction. Based on UV-vis-DRS, photoluminescence and time-resolved fluorescence lifetime measurements, the cooperative effect between BaTiO3 and CaFe2O4 originated from the improved photoresponse in the visible light region and efficient separation of the photogenerated electronehole pairs augmenting their availability for the photocatalytic reaction. A plausible photocatalytic mechanism was also deduced using electrochemical impedance spectroscopy measurements, describing the migration direction of the separated charge carriers. Moreover, the best composite BaTiO3/CaFe2O4 (40 wt %) exhibited fairly stable photoactivity for H2 production using the sacrificial agent (Na2S and Na2SO3) without the assistance of any noble metals as cocatalysts.
关键词： Cocatalyst free,BaTiO3/CaFe2O4 composite,Hydrogen evolution,Sonication-calcination method,Heterojunction
更新于2025-09-09 09:28:46
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Graphitic Carbon Nitride Impregnated Niobium Oxide (g-C <sub/>3</sub> N <sub/>4</sub> /Nb <sub/>2</sub> O <sub/>5</sub> ) Type (II) Heterojunctions and Its Synergetic Solar-Driven Hydrogen Generation
摘要： Graphitic carbon nitride (g-C3N4) based catalysts are evolving in energy harvesting applications due to their robustness, nontoxicity, and most important photocatalytic efficiencies. In this work, we successfully engineered g-C3N4/Nb2O5 type (II) heterojunction via pulse sonochemical technique based on opposite charge-induced hetero-aggregation on the surface. The agglomerated spherical Nb2O5 nanoparticles (NPs) having diameter 30-40 nm observed on the lamellar surface of g-C3N4 in FESEM images. The XRD and XPS analysis confirm the orthorhombic phase and formation of the g-C3N4/Nb2O5 heterostructure. The FTIR spectra of g-C3N4/Nb2O5 show characteristic poly s-triazine bands from 1250 to 1650 cm-1. Moreover, g-C3N4/Nb2O5 exhibited the lower bandgap value of 2.82 eV as compared to Nb2O5 (3.25eV) with significant redshift and enhance visible light absorption. The Mott-Schottky (MS) analysis confirms the formation of heterojunction between g-C3N4 and Nb2O5, with significant band shifting towards lower hydrogen evolution reaction (HER) potential. The g-C3N4/Nb2O5 heterojunctions showed many folds enhanced photocurrent response from photoelectrochemical (PEC) water splitting, and the value reached to – 0.17 mA/cm2 with good stability and insignificant dark photocurrent at 1.0 V vs RHE. The electrochemical impedance spectroscopic (EIS) measurements further elucidate the suppression of photogenerated electrons/holes as the radius of the semicircle significantly decreased in case of heterojunction formation. The enhanced photocatalytic hydrogen generation by the heterostructures could be attributed to the effective formation of heterojunctions between the g-C3N4 and Nb2O5 semiconductors, causing the migration of the photogenerated electrons and holes, hence increasing their lifetimes.
关键词： Pulse Sonication,PEC Water Splitting,g-C3N4,Photocurrent density,Nb2O5 NPs
更新于2025-09-09 09:28:46