Mixed Solution Research Articles

Unlocking the potential of biochar: an iron-phosphorus-based composite modified adsorbent for adsorption of Pb(II) and Cd(II) in aqueous environments and response surface optimization of adsorption conditions.

In this work, iron-phosphorus based composite biochar (FPBC) was prepared by modification with potassium phosphate and iron oxides for the removal of heavy metal ions from single and mixed heavy metal (Pb and Cd) solutions. FTIR and XPS characterization experiments showed that the novel modified biochar had a greater number of surface functional groups compared to the pristine biochar. The maximum adsorption capacities of FPBC for Pb(II) and Cd(II) were 211.66mg·g-1 and 94.08mg·g-1 at 293K. The adsorption of Pb(II) and Cd(II) by FPBC followed the proposed two-step adsorption kinetic model and the Freundlich isothermal adsorption model, suggesting that the mechanism of adsorption of Pb(II) and Cd(II) by FPBC involved chemical adsorption of multiple layers. Mechanistic studies showed that the introduction of -PO4 and -PO3 chemisorbed with Pb(II) and Cd(II), and the introduction of -Fe-O increased the ion exchange with Pb(II) and Cd(II) during the adsorption process and produced precipitates such as Pb3Fe(PO4)3 and Cd5Fe2(P2O7)4. Additionally, the abundant -OH and -COOH groups also participated in the removal of Pb(II) and Cd(II). In addition, FPBC demonstrated strong selective adsorption of Pb(II) in mixed heavy metal solutions. The Response Surface Methodology(RSM) analysis determined the optimal adsorption conditions for FPBC as pH 5.31, temperature 26.01°C, and Pb(II) concentration 306.30mg·L-1 for Pb(II). Similarly, the optimal adsorption conditions for Cd(II) were found to be pH 5.66, temperature 39.34°C, and Cd(II) concentration 267.68mg·L-1. Therefore, FPBC has the potential for application as a composite-modified adsorbent for the adsorption of multiple heavy metal ions.

Toward Selective Transport of Monovalent Metal Ions with High Permeability Based on Crown Ether-Encapsulated Metal-Organic Framework Sub-Nanochannels.

Achieving selective transport of monovalent metal ions with high precision and permeability analogues to biological protein ion channels has long been explored for fundamental research and various applications, such as ion sieving, mineral extraction, and energy harvesting and conversion. However, it still remains a significant challenge to construct artificial nanofluidic devices to realize the trade-off effects between selective ion transportation and high ion permeability. In this work, we report a bioinspired functional micropipet with in situ growth of crown ether-encapsulated metal-organic frameworks (MOFs) inside the tip and realize selective transport of monovalent metal ions. The functional ion-selective micropipet with sub-nanochannels was constructed by the interfacial growth method with the formation of composite MOFs consisting of ZIF-8 and 15-crown-5. The resulting micropipet device exhibited obvious monovalent ion selectivity and high flux of Li+ due to the synergistic effects of size sieving in subnanoconfined space and specific coordination of 15-crown-5 toward Na+. The selectivity of Li+/Na+, Li+/K+, Li+/Ca2+, and Li+/Mg2+ with 15-crown-5@ZIF-8-functionalized micropipet reached 3.9, 5.2, 105.8, and 122.4, respectively, which had an obvious enhancement compared to that with ZIF-8. Notably, the ion flux of Li+ can reach up to 93.8 ± 3.6 mol h-1·m-2 that is much higher than previously reported values. Furthermore, the functional micropipet with 15-crown-5@ZIF-8 sub-nanochannels exhibited stable Li+ selectivity under various conditions, such as different ion concentrations, pH values, and mixed ion solutions. This work not only provides new opportunities for the development of MOF-based nanofluidic devices for selective ion transport but also facilitates the promising practical applications in lithium extraction from salt-like brines, sewage treatment, and other related aspects.

The Synthesis of Ag/TiO2 via the DC Magnetron Sputtering Method and Its Application in the Photocatalytic Degradation of Methyl Orange in Na2SO4 Solution

TiO2 and TiO2 films modified with Ag (Ag/TiO2) were prepared via the DC magnetron sputtering method and the degree of modification was controlled via the sputtering power and time of Ag. The microstructures and properties of these films were characterized using field emission scanning electron microscopy, X-ray diffractometry, ultraviolet–visible diffuse reflectance spectrometry, atomic force microscopy, and X-ray photoelectron spectroscopy (XPS). The results show that the prepared films have an anatase structure. Compared with pure TiO2, Ag deposition can improve the utilization of light. The three-dimensional images of Ag/TiO2 clearly show that with the increase in Ag sputtering power and sputtering time, Ag particles on the surface of the film gradually increase, and the structure of the film is relatively dense. The photocatalytic effect of Ag/TiO2 films is the best when the Ag sputtering power is 5 W and the sputtering time is 50 s. Under high-pressure mercury lamp irradiation, the photocatalytic degradation rate of methyl orange (MO) in pure MO solution with Ag/TiO2-5 W-50 s can reach 100% within 55 min, whereas that in MO-Na2SO4 mixed solution can reach 99.55% within 65 min. The results suggest that the presence of Na2SO4 in MO solution can inhibit the degradation of MO using Ag/TiO2, the result of XPS suggests that Na2SO4 accelerates the oxidation of Ag, which may lead to an increase in the recombination rate of photogenerated electron–hole pairs and a decrease in the degradation rate. During the process of recycling photocatalysts, the degradation rate of MO was apparently reduced. A possible reason is that the Ag particles have been oxidized and products of photocatalytic degradation are on the surface of the photocatalyst. The photocatalytic degradation mechanism was studied.

Optofluidic SERS based on Ag nanocubes with high sensitivity for detecting a prevalent water pollutant.

To enhance the integration and practical applicability of the Raman detection system, silver nanocubes (Ag NCs) were synthesized using a polyol method. A liquid-liquid interface approach was employed to transfer a monolayer of Ag NCs "film" onto a SiO2 substrate, resulting in the fabrication of a highly sensitive and uniform surface-enhanced Raman scattering (SERS) substrate denoted as "Ag NCs@SiO2." The electromagnetic field distribution of various dimers on the Ag NCs@SiO2 was analyzed using finite difference time domain (FDTD) software. The results reveal that the electromagnetic enhancement effect is most pronounced in cube-cube dimers, indicating that Ag NCs exhibit superior localized surface plasmon resonance (LSPR) response due to their well-defined geometric regularity and sharp geometric angles. For Rhodamine 6G (R6G) probe molecules, the Ag NCs@SiO2 shows ultrahigh sensitivity, with a limit of detection (LOD) of 10-12 mol/L, and the enhancement factor (EF) can reach 1.4 × 1010. The relative standard deviation (RSD) at the main characteristic peaks is below 10%, demonstrating good consistency in substrate performance. In addition, the Ag NCs@SiO2 modified with hexanethiol exhibits high sensitivity, uniformity, and repeatability in detecting for pyrene, with the LOD of 10-8 mol/L and a minimum RSD of 6.09% at the main characteristic peak, and effective recognition capabilities for pyrene and anthracene in mixed solutions. Finally, chemisorption and physisorption strategies were prepared in optofluidic channels and experimentally compared, enabling real-time detection of the pyrene solution. This method can achieve a rapid detection and precise differentiation of polycyclic aromatic hydrocarbons in a water pollutant.

Fluorescence Turn-on Detection of Perfluorooctanoic Acid (PFOA) by Perylene Diimide-Based Metal-Organic Framework.

A novel, water-stable, perylene diimide (PDI) based metal-organic framework (MOF), namely, U-1, has been synthesized for selective and sensitive detection of perfluorooctanoic acid (PFOA) in mixed aqueous solutions. The MOF shows highly selective fluorescence turn-on detection via the formation of a PFOA-MOF complex. This PFOA-MOF complex formation was confirmed by various spectroscopic techniques. The detection limit of the MOF for PFOA was found to be 1.68 μM in an aqueous suspension. Upon coating onto cellulose paper, the MOF demonstrated a significantly lower detection limit, down to 3.1 nM, which is mainly due to the concentrative effect of solid phase extraction (SPE). This detection limit is lower than the fluorescence sensors based on MOFs previously reported for PFAS detection. The MOF sensor is regenerable and capable of detecting PFOA in drinking and tap water samples. The PDI-MOF-based sensor reported herein represents a novel approach, relying on fluorescence turn-on response, that has not yet been thoroughly investigated for detecting per- and polyfluoroalkyl substances (PFAS) until now.

Boron-incorporated IrO2-Ta2O5 coating as an efficient electrocatalyst for acidic oxygen evolution reaction

The Ir-based electrocatalysts for the acidic oxygen evolution reaction (OER) have demonstrated remarkable durability. Enhancing the Ir-based electrocatalytic activity still remains crucial owing to the scarcity of iridium. Here, a high-temperature sintering technique is employed to fabricate a boron (B)-incorporated IrO2-Ta2O5 coating with an almost perfect rutile-type crystal structure on a corrosion-resistant titanium substrate, ensuring exceptional stability for the acidic OER. The B-incorporated IrO2-Ta2O5 electrode fabricated in a mixed solution of 0.6 M H3BO3, exhibits an overpotential of 210 mV at a current density of 10 mA cm−2 and a lower Tafel slope of 34.2 mV dec−1 in a 0.5 M H2SO4 solution, which is far lower than the 272 mV overpotential and the 45.3 mV dec−1 of the IrO2-Ta2O5/Ti electrode. The electrode possesses a minimal potential increase even after undergoing continuous OER for 400 h at a high current density of 100 mA cm−2 in a 0.5 M H2SO4 solution. The incorporation of B species into IrO2-Ta2O5 effectively fine-tunes the electronic structure of Ir active sites, leading to a substantial enhancement of the intrinsic electrocatalytic activity. This study provides promising prospects for reducing the energy consumption of noble IrO2-based electrocatalysts in the practical application of electrochemical industry for the acidic OER.

Effects of improved amino acid balance diet on lysine mammary utilization, whole body protein turnover and muscle protein breakdown on lactating sows

BackgroundThe study objective was to test the hypothesis that low crude protein (CP) diet with crystalline amino acids (CAA) supplementation improves Lys utilization efficiency for milk production and reduces protein turnover and muscle protein breakdown. Eighteen lactating multiparous Yorkshire sows were allotted to 1 of 2 isocaloric diets (10.80 MJ/kg net energy): control (CON; 19.24% CP) and reduced CP with “optimal” AA profile (OPT; 14.00% CP). Sow body weight and backfat were recorded on d 1 and 21 of lactation and piglets were weighed on d 1, 14, 18, and 21 of lactation. Between d 14 and 18, a subset of 9 sows (CON = 4, OPT = 5) was infused with a mixed solution of 3-[methyl-2H3]histidine (bolus injection) and [13C]bicarbonate (priming dose) first, then a constant 2-h [13C]bicarbonate infusion followed by a 6-h primed constant [1-13C]lysine infusion. Serial blood and milk sampling were performed to determine plasma and milk Lys enrichment, Lys oxidation rate, whole body protein turnover, and muscle protein breakdown.ResultsOver the 21-d lactation period, compared to CON, sows fed OPT had greater litter growth rate (P < 0.05). Compared to CON, sows fed OPT had greater efficiency of Lys (P < 0.05), Lys mammary flux (P < 0.01) and whole-body protein turnover efficiency (P < 0.05). Compared to CON, sows fed OPT tended to have lower whole body protein breakdown rate (P = 0.069). Muscle protein breakdown rate did not differ between OPT and CON (P = 0.197).ConclusionFeeding an improved AA balance diet increased efficiency of Lys and reduced whole-body protein turnover and protein breakdown. These results imply that the lower maternal N retention observed in lactating sows fed improved AA balance diets in previous studies may be a result of greater partitioning of AA towards milk rather than greater body protein breakdown.

Synergistic effects of nonionic surfactants ethoxylated alkylamines and sodium dodecyl sulfate in mixed systems

HypothesisIn general, the performance of surfactant hybrid systems is better than that of single surfactants, so surfactant hybrid systems are widely used in various industries. As a very important class of nonionic surfactants, ethoxylated alkylamines have been widely used in industries such as washing, coating, and pesticide, but little research has been conducted on their mixed systems. In order to improve the utilization efficiency of surfactants and reduce wastage, the surface properties and aggregation behavior of ethoxylated alkylamine mixed systems should be further explored. ExperimentIn this study, the nonionic surfactant ethoxylated dodecylamine (AC-1202) and the anionic surfactant sodium dodecyl sulfate (SDS) were used to form a mixed system. The static surface tension and interaction parameters of the mixed system under the influence of inorganic salt ions were investigated using a KRÜSS K12 surface tensiometer. The diffusion process of the mixed system was investigated using a KRÜSS bubble pressure tensiometer. At the same time, the aggregate behavior of the mixed system was studied by particle size analyzer. In addition, the contact angle and rheological properties of the mixed solution were also investigated. FindingsThe SDS/AC-1202 mixture system formed a synergistic effect that could reduce the CMC value to 24.20 mN/m and the CMC value was as low as 22.89 mN/m after the addition of inorganic salts. The mixed system conforms to the kinetic mechanism of mixing and diffusion and the Ostwald de model for non-Newtonian fluids. Finally, there is a good aggregation pattern in the mixed system, and the stronger synergistic effect will lead to the reduction of the average particle size of the mixture to 45.41 nm.

Genotoxicological and physiological effects of glyphosate and its metabolite, aminomethylphosphonic acid, on the freshwater invertebrate Lymnaea stagnalis

Aminomethylphosphonic acid (AMPA) is the main metabolite in the degradation of glyphosate, a broad-spectrum herbicide, and it is more toxic and persistent in the environment than the glyphosate itself. Owing to their extensive use, both chemicals pose a serious risk to aquatic ecosystems. Here, we explored the genotoxicological and physiological effects of glyphosate, AMPA, and the mixed solution in the proportion 1:1 in Lymnaea stagnalis, a freshwater gastropod snail. To do this, adult individuals were exposed to increasing nominal concentrations (0.0125, 0.025, 0.050, 0.100, 0.250, 0.500 µg/mL) in all three treatments once a week for four weeks. The genotoxicological effects were estimated as genomic damage, as defined by the number of micronuclei and nuclear buds observed in hemocytes, while the physiological effects were estimated as the effects on somatic growth and egg production. Exposure to glyphosate, AMPA, and the mixed solution caused genomic damage, as measured in increased frequency of micronuclei and nuclear buds and in adverse effects on somatic growth and egg production. Our findings suggest the need for more research into the harmful and synergistic effects of glyphosate and AMPA and of pesticides and their metabolites in general.

Enhanced Hydrogen Evolution in Porous and Hybrid g‐C3N4/Pt‐PVDF Electrospun Membranes via Piezoelectricity from Water Flow Energy

AbstractInspired from seaweed swayed by waves, the enhanced hydrogen evolution is realized in porous and hybrid g‐C3N4/Pt‐PVDF electrospun membranes via piezoelectricity from water flow energy. The membranes are fabricated by dispersing g‐C3N4/Pt into the mixed solution of PVDF and PEO, followed by electrospinning and selective removal of PEO. By changing the PEO amount, the pore size in nanofibers is adjusted. Due to the hydrogen bonding between g‐C3N4/Pt and PVDF, the β phase of PVDF is increased, beneficial for the piezoelectricity performance. When the electrospun membranes are exposed to water flow, an additional potential field is triggered due to the deformation of PVDF. It not only eases the photogeneration of charge carriers from g‐C3N4/Pt but also hinders their recombination. The prolonged lifetime significantly improves the photocatalytic water splitting of g‐C3N4/Pt under visible light. The hydrogen evolution in the electrospun membranes (PVDF to PEO = 4:1) is profoundly improved to 9 278 µmol h−1 g−1, almost doubled to the pure g‐C3N4/Pt nanosheets (5 220 µmol h−1 g−1). Therefore, the seaweed‐inspired electrospun membrane is a promising strategy for the efficiently photocatalytic water splitting via g‐C3N4 in an aqueous environment, such as a natural sea and lake, by the piezoelectricity gained from the water flow energy.

Research on triamterene equilibrium solubility in mono-solvents and aqueous solutions according to solvent effect, models, thermodynamic analysis and quantum chemical calculation

The equilibrium solubilities of triamterene in pure solvents {isopropanol, methanol, n-propanol, water, 1,2-dichloroethane, 2-methoxyethanol, ethyl acetate, acetonitrile, N-methylformamide (NMF), n-butanol, isobutanol and dimethylsulfoxide (DMSO)}, as well as solvent mixtures of methanol/DMSO + water, were determined by dint of the saturation shake-flask technique. Triamterene solubility (105x) rose as the determination temperature rose and fell in the order at 298.15 K: 2-methoxyethanol (453.9) > DMSO (281.3) > NMF (142.6) > methanol (8.424) > n-propanol (1.432) > n-butanol (1.152) > ethyl acetate (0.9441) > isobutanol (0.8738) > acetonitrile (0.7991) > isopropanol (0.7419) > 1,2-dichloroethane (0.5232) > water (0.1795). No crystal transition or solvation in the trial process was shown via X -ray power diffraction patterns. The solvent effects, in which the interactions of solvent–solvent and solvent–solute were considered, were studied via linear solvation energy relationship. Using equations such as Wilson, Apelblat, λh, and NRTL for mono-solvents and Jouyban-Acree as well as modified van't Hoff-Jouyban-Acree for solvent mixtures, the magnitudes of equilibrium solubility were associated. The greatest relative average deviation of 5.787 × 10−2 and the maximum deviation value of root mean square of 219.1 × 10−4 were computed for neat solvents. According to the solubility information in pure solvents, the Wilson equation was used to compute the mixing solution parameters. At 298.15 K, the inverse Kirkwood-Buff integral was utilized here to examine the preferred solvation of triamterene. In blends of DMSO/methanol + water with middle and rich DMSO/methanol compositions, the parameters of preferred solvation for DMSO/methanol were positive, indicating the preferential solvation of triamterene by DMSO/methanol. In addition, the electrostatic acidity-basicity properties were demonstrated using the lowest negative electrostatic potential in company with the minimum m local ionization energy of molecular surface. The N in ring of the triamterene is the preferential target for electrophilic assault; and –NH2 of the triamterene, for nucleophilic assault. The weak triamterene-solvent interactions were graphically displayed by the use of the independent gradient approach on the basis of Hirshfeld partition analysis.

Multiwaves, breathers, lump and other solutions for the Heimburg model in biomembranes and nerves

In this manuscript, a mathematical model known as the Heimburg model is investigated analytically to get the soliton solutions. Both biomembranes and nerves can be studied using this model. The cell membrane’s lipid bilayer is regarded by the model as a substance that experiences phase transitions. It implies that the membrane responds to electrical disruptions in a nonlinear way. The importance of ionic conductance in nerve impulse propagation is shown by Heimburg’s model. The dynamics of the electromechanical pulse in a nerve are analytically investigated using the Hirota Bilinear method. The various types of solitons are investigates, such as homoclinic breather waves, interaction via double exponents, lump waves, multi-wave, mixed type solutions, and periodic cross kink solutions. The electromechanical pulse’s ensuing three-dimensional and contour shapes offer crucial insight into how nerves function and may one day be used in medicine and the biological sciences. Our grasp of soliton dynamics is improved by this research, which also opens up new directions for biomedical investigation and medical developments. A few 3D and contour profiles have also been created for new solutions, and interaction behaviors have also been shown.

Fabrication of Al doped α-GaOOH nanorod arrays on FTO for self-powered photoelectrochemical solar-blind UV photodetectors

Abstract Al doped α-GaOOH nanorod arrays were grown on FTO via hydrothermal processes by using gallium nitrate and aluminium nitrate mixed aqueous solutions with fixed 1:1 mole ratio as precursors. With increasing the gallium nitrate precursor concentrations, the Ga/Al atom ratio in nanorod arrays increase from 0.36 to 2.08, and the length becomes much longer from 650 nm to 1.04 μm. According to the binding energy difference between Ga 2p3/2 core level and its background in XPS, the bandgap is estimated to be around 5.3±0.2 eV. Al doped α-GaOOH nanorod array/FTO photoelectrochemical (PEC) photodetectors shows enhanced self-powered solar-blind UV photodetection properties, with the decrease of Ga precursor concentrations. The maximum responsivity at 255 nm is 0.09 mA/W, and the fastest response time can reach 0.05s. The improved photoresponse speed is ascribed from much shorter transportation route, accelerated carrier recombination by recombination centers, and smaller charge transfer resistance at the α-GaOOH/electrolyte interface with decreasing the gallium nitrate precursor concentrations. The stability and responsivity should be further improved. Nevertheless, this work firstly demonstrates the realization of self-powered solar-blind UV photodetection for α-GaOOH nanorod arrays on FTO via Al doping.

Experimental investigation of a mixed desiccant solution of potassium formate and ionic liquid

Liquid desiccant technology is a promising energy-efficient alternative to conventional temperature and humidity control systems. In the quest to identify the optimal fluid for liquid desiccant systems, alternative desiccant solutions have been explored in terms of their feasibility and compatibility in dehumidification systems. This study proposes and characterises a new type of less expensive mixture of potassium formate (HCO2K) and 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]). This novel desiccant solution was investigated in terms of corrosiveness to metals, moisture absorption and desorption ability, cost-effectiveness compared to conventional desiccant solutions. The corrosiveness of desiccant solutions to copper-nickel, copper and steel was tested at room temperature and at 60 °C. Experiments were conducted in a climatic chamber with temperatures of 25–31 °C and relative humidities of 80–90% for the absorption process and temperatures of 50–70 °C and relative humidities of 20–30% for the desorption process to assess the moisture absorption and desorption capacities and mass fraction variations of the desiccant solutions. The mixed desiccant of HCO2K/[EMIM][OAc] in the ratio 60/10% wt. showed a moisture absorption capacity of 0.146 gH2O/gsol (compared to 0.18 gH2O/gsol for aqueous lithium chloride at 33.3% wt.) for a temperature and relative humidity of the climatic chamber of 25 °C and 90%, respectively. Its low corrosiveness, good moisture absorption and desorption capacity and higher cost-effectiveness make it a promising alternative to conventional desiccants, such as aqueous solutions of lithium chloride.

A novel method for quantitative determination of multiple substances using Raman spectroscopy combined with CWT

The identification of mixed solutions is a challenging and important subject in chemical analysis. In this paper, we propose a novel workflow that enables rapid qualitative and quantitative detection of mixed solutions. We use a methanol-ethanol mixed solution as an example to demonstrate the superiority of this workflow. The workflow includes the following steps: (1) converting Raman spectra into Raman images through CWT; (2) using MobileNetV3 as the backbone network, improved multi-label and multi-channel synchronization enables simultaneous prediction of multiple mixture concentrations; and (3) using transfer learning and multi-stage training strategies for training to achieve accurate quantitative analysis. We compare six traditional machine learning algorithms and two deep learning models to evaluate the performance of our new method. The experimental results show that our model has achieved good prediction results when predicting the concentration of methanol and ethanol, and the coefficient of determination R2 is greater than 0.999. At different concentrations, both MAPE and RSD outperform other models, which demonstrates that our workflow has outstanding analytical capabilities. Importantly, we have solved the problem that current quantitative analysis algorithms for Raman spectroscopy are almost unable to accurately predict the concentration of multiple substances simultaneously. In conclusion, it is foreseeable that this non-destructive, automated, and highly accurate workflow can further advance Raman spectroscopy.

Insight into the Mechanisms of Efficient Selective Removal of Pb2+ from Wastewater by Nano-flowered MoS2/NHCS Electrodes

The shortage of clean water resources has become a major challenge to global sustainable development, and lead (Pb) pollution in natural water has made the issue even more severe. Efficiently removal of Pb2+ is a severe challenge to Lead-containing sewage disposal. Here, efficiently selective removal of Pb2+ from wastewater was tested over hollow nano-flowered MoS2/N-doped hollow carbon spheres (MoS2/NHCS) cathodes by capacitive deionization (CDI) process. The MoS2/NHCS electrodes exhibited an excellent removal efficiency of 96.9% in 20 ppm Pb(NO3)2 solution at U = 1.2V, pH = 6, and 40mL/min of flow rate. In addition, MoS2/NHCS electrodes showed excellent regeneration ability in 10 ppm Pb2+ solution and still could reach 97.7% after 20 cycles, especially the good selective removal efficiency in the mixed solution. In situ Raman spectrum and DFT calculations indicate that efficient selective removal of Pb2+ was attributed to Pb2+ directly combined with partially negatively charged S2- to generate PbS, and some S ions transformed into S2-2 by received electrons, which further combines with Pb2+ to form PbS2. Hence, this work proposes an innovative adsorption mechanism for selective capacitive removal of Pb2+ and provides the potential practical application for treating Lead-containing wastewater.

Layer-by-layer self-assembly of PLL/CPP-ACP multilayer on SLA titanium surface: Enhancing osseointegration and antibacterial activity in vitro and in vivo

Implants are expected to possess both excellent osteointegration and antibacterial activity because poor osseointegration and infection are two major causes of titanium implant failure. In this study, we constructed layer-by-layer self-assembly films consisting of anionic casein phosphopeptides-amorphous calcium phosphate (CPP-ACP) and cationic poly (L-lysine) (PLL) on sandblasted and acid etched (SLA) titanium surfaces and evaluated their osseointegration and antibacterial performance in vitro and in vivo. The surface properties were examined, including microstructure, elemental composition, wettability, and Ca2+ ion release. The impact the surfaces had on the adhesion, proliferation and differentiation abilities of MC3T3-E1 cells were investigated, as well as the material’s antibacterial performance after exposure to the oral microorganisms such as Porphyromonas gingivalis (P. g) and Actinobacillus actinomycetemcomitans (A. a). For the in vivo studies, SLA and Ti (PLL/CA-3.0)10 implants were inserted into the extraction socket immediately after extracting the rabbit mandibular anterior teeth with or without exposure to mixed bacteria solution (P. g & A. a). Three rabbits in each group were sacrificed to collect samples at 2, 4, and 6 weeks of post-implantation, respectively. Radiographic and histomorphometry examinations were performed to evaluate the implant osseointegration. The modified titanium surfaces were successfully prepared and appeared as a compact nano-structure with high hydrophilicity. In particular, the Ti (PLL/CA-3.0)10 surface was able to continuously release Ca2+ ions. From the in vitro and in vivo studies, the modified titanium surfaces expressed enhanced osteogenic and antibacterial properties. Hence, the PLL/CPP-ACP multilayer coating on titanium surfaces was constructed via a layer-by-layer self-assembly technology, possibly improving the biofunctionalization of Ti-based dental implants.

Rapid Fabrication of Binder Free Nickel Cobalt Oxide Electrodes with Forest-Like Architecture for Electrochemical Energy Storage Applications

A rapid and facile technique to synthesize nickel cobalt oxide electrodes by photothermal treatment of mixed organometallic precursor solution is reported. Using short and intense pulses of light from a xenon flash lamp, spray coated films are converted into porous nickel cobalt oxide electrodes with forest-like architecture. The electrode films fabricated in a few seconds show excellent energy storage properties as supercapacitor electrodes. Specific capacitance of up to 116 Fg-1 and capacitance retention of up to 75% were observed in samples with low mass loading. Analysis of the cyclic voltammetry (CV) curves shows that capacitance is the dominating charge storage mechanism in these films. To study the effect of varying the mass loading in electrodes, double and triple layered electrodes were also studied. In films with high mass loading, the specific capacitance of the films decreased but areal capacitance continued to increase. A high areal capacitance of up to 243 mFcm-2 is observed in films with high mass loading. CV curve analysis of high mass loading electrodes further shows that in films with higher mass loading, the charge storage mechanism is a mix of capacitance and diffusion processes. The contribution of diffusion process increased with increase in the mass loading of the electrodes. This study sheds light into the mechanism of charge storage in electrodes prepared by large scale amenable single step process of photonic curing which could be utilized to fabricate electrodes in industrial scale.

Effect of milk protein-galactomannans interaction on meltdown behavior in the aerated frozen model system

The microstructure of ice cream and frozen desserts is known to influence their meltdown behavior. In this study, we hypothesized that the interaction of milk protein and galactomannans, specifically the phase separation often observed between hydrocolloids and protein, along with the interaction of hydrocolloids in the serum phase, affected meltdown behavior in non-fat aerated frozen foam. Ice creams were made with protein contents from 4 to 8%, with the addition of guar gum or locust bean gum. The effect of κ-carrageenan in protein and galactomannans was also studied. Melting characteristics were compared to the rheological and structural characteristics of the ice cream as well as to the phase separation in the mix and drip-through solution. The freezing-melting process inhibited microscopic and macroscopic phase separation in most locust bean gum samples, primarily due to the cryo-gel maintaining structural integrity and altering hydrocolloid-proteins interactions. The cryo-gel structure also led to slow melting rates and stable melted foams in the 4% milk protein system even in the absence of milk fat globules and clusters. Increasing milk protein from 4% to 8% in locust bean gum samples resulted in faster melting and a transition to complete dripping, indicating the disruption of the cryo-gel structure by increased proteins. In contrast, all guar gum samples fully dripped through the mesh with a fast melting rate. A negative trend was found between phase separation and melting rate in the guar gum samples containing κ-carrageenan, indicating that the diminishing interaction between the two immiscible phases accelerated liquid drainage.

Antiadhesive, antibacterial, and anti-inflammatory sandwich-structured ZIF8-containing gauze for enhanced wound healing

Medical gauze is commonly used in clinical practice due to its low irritation, flexibility, and permeability. However, conventional gauze frequently lacks adequate antibacterial and anti-adhesion properties, and gauze that is only superhydrophobic or antibacterial seldom meets the full requirements of infected wound treatment. In this work, we report optimal air permeability, water and blood absorption, and biocompatibility, and effective antibacterial properties of a sandwich-structured gauze composed of a superhydrophobic outer layer, a zeolite imidazolate framework-8 (ZIF8) interlayer, and a superhydrophobic inner layer containing blood-drainage channels (denoted SZS gauze). Three ZIF8 interlayers, ZIF8-1, ZIF8-2, and ZIF8-3, were prepared by soaking medical gauze samples in a mixed solution of 50 mL methanol, 50 mL ethanol, and 0.25, 0.50, or 1.00 g zinc acetate before flat drying, and had Zn content of 0.28, 0.34, and 0.46at.%, respectively, and their corresponding SZS gauze samples are denoted SZS-1, SZS-2, and SZS-3, respectively. Among all gauze samples, the SZS-2 showed the highest cytocompatibility toward L929 cells and effective in vitro antibacterial ability against E.coli and S.aureus. In a rat subcutaneous inflammation model, the SZS-2 showed complete biosafety and the best antibacterial and anti-inflammatory effects against E.coli and S.aureus mixed bacteria among all gauze samples including standard medical gauze and a sandwich-structured gauze with a blank interlayer between two superhydrophobic layers. These findings indicate that the SZS-2 gauze is a promising candidate for advanced wound care, particularly in the management of infected wounds.