Sequential Chemical Treatment Research Articles

Efficient surface passivation of germanium nanostructures with 1% reflectance

Germanium (Ge) is a vital element for applications that operate in near-infrared wavelengths. Recent progress in developing nanostructured Ge surfaces has resulted in >99% absorption in a wide wavelength range (300–1700 nm), promising unprecedented performance for optoelectronic devices. However, excellent optics alone is not enough for most of the devices (e.g. PIN photodiodes and solar cells) but efficient surface passivation is also essential. In this work, we tackle this challenge by applying extensive surface and interface characterization including transmission electron microscopy and x-ray photoelectron spectroscopy, which reveals the limiting factors for surface recombination velocity (SRV) of the nanostructures. With the help of the obtained results, we develop a surface passivation scheme consisting of atomic-layer-deposited aluminum oxide and sequential chemical treatment. We achieve SRV as low as 30 cm s−1 combined with ∼1% reflectance all the way from ultraviolet to NIR. Finally, we discuss the impact of the achieved results on the performance of Ge-based optoelectronic applications, such as photodetectors and thermophotovoltaic cells.

Fabrication of Sacha Inchi Oil-Loaded Microcapsules Employing Natural-Templated Lycopodium clavatum Spores and Their Pressure-Stimuli Release Behavior.

Polymeric particles have attracted vast attention for use in various fields, especially as drug carriers and cosmetics, due to their excellent ability to protect active ingredients from the environment until reaching a target site. However, these materials are commonly produced from conventional synthetic polymers, which impose adverse effects on the environment due to their non-degradable nature, leading to waste accumulation and pollution in the ecosystem. This work aims to utilize naturally occurring Lycopodium clavatum spores to encapsulate sacha inchi oil (SIO), which contains active compounds with antioxidant activity, by applying a facile passive loading/solvent diffusion-assisted method. Sequential chemical treatments by acetone, potassium hydroxide, and phosphoric acid were employed to remove native biomolecules from the spores before encapsulation effectively. These are mild and facile processes compared to other synthetic polymeric materials. Scanning electron microscopy and Fourier-transform infrared spectroscopy revealed the clean, intact, and ready-to-use microcapsule spores. After the treatments, the structural morphology of the treated spores remained significantly unchanged compared to the untreated counterparts. With an oil/spore ratio of 0.75:1.00 (SIO@spore-0.75), high encapsulation efficiency and capacity loading values of 51.2 and 29.3%, respectively, were obtained. Using antioxidant assay (DPPH), the IC50 of SIO@spore-0.75 was 5.25 ± 3.04 mg/mL, similar to that of pure SIO (5.51 ± 0.31 mg/mL). Under pressure stimuli (1990 N/cm3, equivalent to a gentle press), a high amount of SIO was released (82%) from the microcapsules within 3 min. At an incubation time of 24 h, cytotoxicity tests showed a high cell viability of 88% at the highest concentration of the microcapsules (10 mg/mL), reflecting biocompatibility. The prepared microcapsules have a high potential for cosmetic applications, especially as functional scrub beads in facial washing products.

The mechanism study on the integrated process of NaOH treatment and citric acid leaching for rare earth elements recovery from coal fly ash

Rare earth elements and yttrium (REY) have vital functions in the global economy because of their numerous applications. Coal fly ash (CFA) is considered a potential alternative resource for REY. In this paper, sequential chemical extraction procedure, NaOH treatment, and citric acid leaching were used to study modes of occurrence, enrichment, and recovery of REY in CFA after physical separation. The proportion of REY (84%) bond to aluminosilicate phase in the separated sample is higher than that in the raw CFA. Monazite, apatite, scheelite, and aluminosilicate phase were proved to be REY carriers via SEM-EDS observation. REY in CFA was enrichment by NaOH treatment, and the glassy phase dissolution conformed to shrinking core model. The dissolution was first controlled by a chemical reaction and then inner diffusion, with activation energies of 70.89 and 3.21 kJ/mol and reaction orders of 1.02 and 0.73, respectively. The gel conjunction and zeolite generation limited CFA dissolution, concluded from the chemical reaction verification, SEM observation, and XRD analysis. The REY content after multi-step NaOH treatment increased to 2135 μg/g with an enriched factor of 2.08. Citric acid (0.05 mol/L) leaching was investigated and REY recovery is 55%. A conceptual integrated process of NaOH treatment and citric acid leaching for the CFA utilization was designed. This paper will provide a theoretical fundamental and technological support for REY recovery.

Preparation of porous microcrystalline cellulose from mezcal industry agave bagasse by low reagent loading sequential chemical treatment

Preparation of porous microcrystalline cellulose from mezcal industry agave bagasse by low reagent loading sequential chemical treatment

Reduction in the resistance of poly(3,4-ethylenedioxythiophene):poly(styrene sulphonate) (PEDOT:PSS) films by sequential chemical treatment

The effect of sequential chemical treatment on the room temperature electrical resistance of sub-micron-thick poly(3,4-ethylenedioxythiophene):poly(styrene sulphonate) (PEDOT:PSS) films was studied. The resistance of PEDOT:PSS films was found to be highly dependent on the molar concentration, type of solvent and number of successive treatments. An effective decrease in the resistance value from ∼415 Ω to ∼35 Ω was achieved upon successive treatments of pristine film twice with dimethyl sulfoxide and one time with 0.5 M sulfuric acid. Interestingly, the resistance of the film was found to depend on the sequence of the successive treatment of both the solvents. The appearance of sharp peak in XRD after acid treatment suggests enhancement in the crystallinity of the PEDOT:PSS films. Raman spectroscopy was employed to monitor the structural changes (coil to extended linear coil conformation) that results in an improvement in the conductance of the treated films.

Statistically optimized sequential hydrothermal route for FeTiO3 surface modification: evaluation of hazardous cationic dyes adsorptive removal.

In the present study, the performance of facile hybrid sequential chemical treatments of titanomagnetite concentrate (TC), alkaline leaching, and sodium dodecyl sulfate (SDS) modification has been evaluated for the removal of crystal violet (CV), malachite green (MG), and methylene blue (MB) cationic dyes. The physical and chemical properties of samples were characterized using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), N2 adsorption-desorption, X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and Fourier transform infrared spectroscopy (FTIR) analyses. Moreover, dye removal in the batch system was investigated by evaluating adsorbent dosage, contact time, initial dye concentration, pH of the solution, temperature, electrolyte concentration, adsorption isotherm, kinetic, and thermodynamic. The results showed that the maximum adsorption capacity was obtained at SDS concentration of 6mM, NaOH concentration of 9M, the temperature of 160°C, solid/liquid ratio of 4g/100mL, and the process duration of 24h. In the alkaline leaching process, forming the Na2TiO3 phase with sharp and high energy points can be improved the adsorption properties. Accordingly, the adsorption capacity and removal efficiency attained 19.84, 18.64, and 19.66mg/g and 99.21, 93.24, and 98.31% for CV, MG, and MB, respectively. Furthermore, the dye removal followed pseudo-second-order (R2 = 0.9990) and Freundlich (R2 = 0.9970) models. The evaluation of thermodynamic parameters indicated the endothermic (∆H° = 110.91J/mol) and spontaneous nature (ΔG˚ < 0) of the adsorption process. This study concluded that the modified TC had a potential ability for application in textile wastewater treatment.

Zinc oxide decorated titania nanostructured layer over Ti metal as a biocompatible and antimicrobial surface for biomedical application

The present study is an attempt to develop a zinc oxide (ZnO) decorated titania (TiO2) nanostructured layer over Ti metal by a simple chemical and thermal treatment method. Ti metal upon sequential chemical treatment with sodium hydroxide and zinc nitrate solution generated a nanostructured network layer enfolded with Zn2+ ions. Subsequent heat treatment up to 500 °C favoured the formation of ZnO and anatase TiO2 while increasing the temperature to 600 °C resulted in the formation of ZnO and ZnTiO3 along with anatase TiO2. This nanostructured layer showed significant improvement in the hardness after heat treatment at 600 °C as measured by the nano-indentation technique. ZnO formed over the anatase TiO2 layer showed excellent antibacterial activity against both gram positive Staphylococcus aureus and gram negative Escherichia coli and was also found to be non-toxic towards MG-63 osteosarcoma cells. Hence, ZnO/ZnTiO3 modified anatase TiO2 over Ti metal is anticipated to reduce the risk of bacterial infection and enhance the proper functionalisation through its metabolic and cellular signalling and can be useful in dental and orthopaedic fields.

Different Sequential Chemical Treatments Used to Obtain Bleached Cellulose from Orange Bagasse

ABSTRACT The development of efficient pretreatments is widely used in biobased products aiming to add value to the residue. In this study, orange bagasse is investigated for cellulose extraction under moderate chemical sequential extraction conditions. Three pretreatments are evaluated: alkaline treatment, organosolv, and residue insoluble alcohol. Then, all pretreated samples are bleached. The results are analyzed by chemical composition, Fourier transformed infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. In general, similar results are observed for all bleaching samples, independently of the pretreatment. A similar cellulose amount is observed among the samples. When compared only to the pretreatments, alkaline shows to be a more effective way of presenting a higher crystallinity index. Hemicellulose and lignin are mostly removed after pretreatment. FTIR and XRD indicated that the pretreatment seems to be more effective in the first step. TG curves presented a more homogeneous pattern due to cellulose removal showing three steps for pre-treatment and two steps for bleached samples. The obtained cellulose has numerous potential applications, and a suitable route can be selected according to available reagents.

Drug and pesticide usage for sea lice treatment in salmon aquaculture sites in a Canadian province from 2016 to 2019

We used 4 years of publicly available data (2016–2019) on chemical usage at salmon sites with information on production, stocking, locations and environmental conditions to explore patterns of anti-sea lice treatments in a Canadian province. Results show that sequential chemical treatments are prevalent, emamectin benzoate (EMB) with azamethiphos being the most used combination with a decrease in ivermectin usage. Relatively high rates of usage of EMB per fish biomass may point to potential lice resistance patterns with information needed on mechanisms and local populations. Lower or no chemical usage at some sites indicate less sea lice infestations likely influenced by localized site conditions (coves), and a lessened need for medication due to the usage of cleaner fish and possibly other non-chemical methods (not documented in this report). The year/climate influenced chemical input only in sites with higher treatment levels likely due to effects on sea lice growth and reproduction. Observed differences between years are warmer surface temperature in the fall, a higher freshwater input in spring, and stronger wind conditions for 2017 and 2018 with more medication usage for these two years. The lack of significant effect of site distances calculated in zones of influence based on 24 h potential connectivity patterns highlight the need to refine the resolution of hydrodynamic processes.

DNA recovery after sequential processing of latent fingerprints on copy paper.

Forensic examiners must determine whether both latent fingerprint development and DNA profiling can be performed on the same area of an evidence item and, if only one is possible, which examination offers the best chance for identification. Latent fingerprints can be enhanced by targeting different components of fingerprint residues with sequential chemical treatments. This study investigated the effects of single‐reagent and sequential latent fingerprint development processes on downstream DNA analysis to determine the point at which latent fingerprint development should be stopped to allow for DNA recovery. Latent fingerprints deposited on copy paper by one donor were developed using three sequential processes: 1,8‐diazafluoren‐9‐one (DFO) → ninhydrin → physical developer (PD); 1,2‐indanedione‐zinc (IND‐Zn) → ninhydrin → PD; and IND‐Zn → ninhydrin → Oil Red O (ORO) → PD. Samples were examined after the addition of each chemical treatment. DNA was collected with cotton swabs, extracted, quantified, and amplified. DNA yields, peak heights, number of alleles obtained, and percentage of DNA profiles eligible for CODIS upload were examined. DNA profiles were obtained with varying degrees of success, depending on the number and type of treatments used for latent fingerprint development. The treatments that were found to be the least harmful to downstream DNA analysis were IND‐Zn and IND‐Zn/laser, and the most detrimental treatments were DFO, DFO/laser, and PD. In general, as the number of treatments increase, the opportunities for DNA loss or damage also increase, and it is preferable to use fewer treatments when developing latent fingerprints prior to downstream DNA processing.

A Comparative Study on Mesoporous Y Zeolites Prepared by Hard-Templating and Post-Synthetic Treatment Methods

Mesoporous Y zeolites were prepared comparatively using the bottom-up templating (with carbon nanotubes, CNTs, and nanocrystalline cellulose, NCC, as the templates) and the top-down post-synthetic treatment (with the sequential chemical and alkaline treatment) methods and characterised comprehensively using various techniques. The relevant findings show that the mesoporous Y zeolites with the intercrystal mesoporosity were prepared by the templating methods, and the NCC is the more effective, economic and sustainable hard template than the CNTs for promoting the formation of intercrystal mesoporosity. While for the post-synthetic strategy, the microwave (MW)-assisted chemical treatment (using ethylenediaminetetraacetic acid, EDTA, as the chemical agent for dealumination) was much more effective than the conventional hydrothermal (HT) treatment for introducing intracrystalline mesoporosity under the comparable condition, e.g. the external surface area: 287 m2 g−1 by 1 min MW treatment vs. 205 m2 g−1 by 6 h HT treatment. The prepared mesoporous Y zeolites, along with the parent Y, were assessed using the catalytic cracking of 1,3,5 triisopriopylbenzene (TiPBz). It was found that the well-developed intracrystalline mesoporosity promoted by the effective MW-assisted post-synthesis method is highly beneficial to the catalysis involving the bulky molecules, and accordingly showed the comparatively best catalytic performance (regarding the conversion and selectivity) among all zeolites under study in this work.

Effect of a Chemical Treatment Series on the Structure and Mechanical Properties of Abaca Fiber (&lt;i&gt;Musa textilis&lt;/i&gt;)

This study investigates the relationships between the composition, cell wall microstructure, and mechanical properties of the abaca fiber. Raw abaca fibers have undergone a series of sequential chemical treatments (acetone/methanol, boiling water, EDTA, HCl, NaClO2, and NaOH) to selectively remove certain non-cellulosic components (NCCs) in the fiber, such as waxes, water-soluble fragments, pectin, and lignin in a step-by-step manner. Changes in composition, morphology, and mechanical properties were observed using FTIR spectroscopy and ion chromatography, digital microscope and SEM, and tensile tests, respectively. The raw fiber was composed of 23% NCCs, 18% hemicellulose, and 58% cellulose, and exhibited a 17.4 GPa Young’s modulus and a 444 MPa tensile strength. Furthermore, the raw abaca fibers demonstrated a linear tensile graph without yielding, and a planar fracture surface without fiber pull-outs, thus suggesting a highly elastic but brittle nature. At the end of the alkali treatment, the fibrillated fiber was 83% cellulose, yet the stiffness and strength dropped to 7.3 GPa and 55 MPa, respectively, as more components were removed, and microfibril relaxation and realignment have occurred. Load-bearing cellulose and hemicellulose accounted for 42% and 36% of the stiffness, respectively, due to –OH groups capable of hydrogen bonding. 63% of the strength was due to thenative NCC matrices, which contribute a significant role within the cell wall’s load-transfer activities.

3D-printed reduced graphene oxide/polylactic acid electrodes: A new prototyped platform for sensing and biosensing applications

This work presents a novel procedure involving the sequential chemical treatment to generate reduced graphene oxide (rGO) within 3D-printed polylactic acid (PLA) electrodes and their potential applications for sensing and biosensing. A new configuration of a compact all-3D-printed electrochemical device containing the three electrodes is presented, in which the working electrode was treated to generate rGO within PLA (rGO-PLA) after treatment within NaBH4. The rGO-PLA electrodes presented a notable current increase for the redox probe ferrocene-methanol in comparison with the same surface treated by dimethylformamide immersion. Also, the electrochemical impedance spectroscopic data that presented the lowest resistance to electron transfer for the proposed electrode. The electrochemical experiments were in accordance with Raman spectra and surface roughness obtained by atomic force microscopy images. As proofs-of-concept, the rGO-PLA electrode was applied for serotonin determination in synthetic urine using differential-pulse voltammetry with a limit of detection of 0.032 μmol L−1. Also, the second application involved the fabrication of a tyrosinase-based biosensor capable of determining catechol in natural water samples with a limit of detection of 0.26 μmol L−1. Based on both applications, the 3D-printed rGO-PLA showed to be an excellent platform for sensing and biosensing purposes.

Survey on chemical, physical, and thermal prediction behaviors for sequential chemical treatments used to obtain cellulose from Imperata Brasiliensis

The effects of chemical treatment sequences on the chemical, physical, and mainly the thermal properties of Imperata Brasiliensis grass in the process used to obtain cellulose fibers were analyzed. The thermal properties were extensively investigated by a thermogravimetric analysis, and a thermal behavior prediction was carried out using kinetic parameters and simulation. Thermal simulations using statistical tools enable thermal predictions for any material under different conditions. However, they are currently not widely reported in the literature for untreated and treated natural fibers. We used an alkaline treatment and alkaline treatment followed by one, two, or three bleaching steps with hydrogen peroxide (H2O2) (24% v/v). After each chemical treatment, changes in chemical composition due to the removal of amorphous constituents were observed and confirmed by the analysis of properties such as coloration, density, porosity, crystallinity, and thermal decomposition. The alkaline treatment followed by one step of bleaching was the most effective and viable chemical treatment sequence to obtain cellulose. The changes in coloration from dark brown to light yellow were accompanied by increases in real density (65%), crystallinity (69%), and thermal stability (27.4%) upon one step of bleaching. In general, the subsequent bleaching steps provided similar values. The predicted thermal degradation profiles were compared with experimental data in order to validate the proposed degradation mechanisms and models. The obtained kinetic parameters adequately described the mass loss histories of the studied natural fibers, even when extremely simplified kinetic schemes were used. The degradation mechanisms consisted of diffusion followed by autocatalytic reactions for all studied fibers.

Enhanced Removal of Phosphorus from Wastewater Using Sequential Electrocoagulation and Chemical Coagulation

An electrokinetic batch treatment scheme was investigated combining sequential electrocoagulation (EC) and chemical coagulation treatment (CC) processes. Synthetic and microbrewery wastewaters were tested in this investigation. The generated results demonstrated the capacity for the integration of EC-CC to effectively remove phosphorus contamination from wastewater under varying operating conditions. The effect of several operational parameters such as current density, conductivity, nutrient loading, and electrolysis time were investigated. The results showed that increased salinity can significantly accelerate the removal of phosphorous during EC treatment with 84.2% and 92.4% removal found for the applied power of 5 and 10 W, respectively. The addition of a sequential chemical coagulant stage following treatment by EC demonstrated the potential for an integrated EC-CC system to lower energy consumption while maintaining effective nutrient removal capabilities. Removal of phosphorous at 95% and 98% was achieved in just 10 min of EC treatment coupled with the addition of 15 mg/L aluminum sulfate. The estimated power consumption over a 10-min period was found to be 0.28 Kwh/m3 with a dissolution rate of 0.28 g/cm2 min held at a constant current density. The experimental anode dissolution rate for the synthetic wastewater ranged between 0.13 and 0.24 g/cm2 min encompassing all salinity levels. The anode dissolution rate increased during treatment of microbrewery wastewater with 0.67 g/cm2 min for 10 W EC treatment. This was attributed to the increase in current density and nutrient loading resulting in increased energy consumption and electrode passivation.

The study of toxic effects of toxic isolate Alternaria alternata in vivo of white mice and the ability of Biological and Chemical treatments in the reduction of toxicity

The study included the detection of the effect of the Mycotoxins of the fungal isolates of Alternaria alternata, which was diagnosed both genetically and chemically by PCR. The analysis showed that the ability of A. alternata to produce toxins, including AltratoxinII, was found in one of the isolates 7.5499μg / ml. This concentration is used in the experiment to determine its effect on the tissues and organs of white mice. In the study, the fungus Pleurotus ostreatus was used to reduce the toxicity of the fungus A. alternata. The fungus P.ostreatus gave high tolerance to A. alternata and evaluated the effect of sequential chemical treatments CaCO3 on reducing the auditory effect on laboratory mice. The toxic isolation of pathogenic fungi is extract into the body of the organism. The effect on the levels of liver enzymes (GPT, GOT, ALP) has reached its level (IU / L) (84, 88, 264) respectively compared to control group which reached (22, 35, 147) IU / L respectively as well, And resulted in the effectiveness of the decomposition of liver cells containing enzymes and led to the liberation of the serum, as well as the cause of changes in the tissue pathological clear in the cross section of the liver tissue, including the occurrence of hepatocytes vaculosis and the presence of bubbles in the cells walls and the expansion of liver sinuses causing Hydropic degeneration. The results of the laboratory examination of the kidney function showed significant differences in the increase in the concentration of urea and creatinine in the serum of laboratory mice treated with urea level (59 mg / dl) and creatinine (1.73 mg / dl) compared to control group (29 mg / dl) And (0.7 mg / dl) respectively, and found a clear effect within the kidney tissues leading to atrophy in the glomeruli, infiltration of the lymphocytes and hemorrhage, in addition to the degradation of urinary tubule cells affecting kidney function leading to renal failure.

Enhancing adhesion properties between binder-free copper nanoink and flexible substrate using chemically generated interlocking structure

Organic residues formed when using organic binders to increase the adhesive strength of Cu ink to PI substrates degrade the electrical conductivity of Cu electrodes. Binder-free Cu ink can be used to fabricate highly conductive Cu electrodes but lead to poor adhesion owing to inherently weak adhesion between the polymer substrates and metals. We therefore propose a facile method to enhance adhesion between a printed copper electrode formed by flash light sintering and a polyimide (PI) substrate without sacrificing the electrical conductivity by forming an interlocking structure at the interface between the Cu electrode made of binder-free ink and PI substrate through simple chemical treatment. The surface of the PI substrate was converted to polyamic acid (PAA) via potassium polyamate formation after sequential chemical treatment using potassium hydroxide and hydrochloric acid. During the flash light sintering process, the PAA layer, which is much softer than PI, could easily migrate into the cavities between the sintered Cu nanoparticles due to the pressure difference originating from evaporation of H2O released through reduction of the oxide shell of Cu nanoparticles. Thus, an interlocking structure was formed and the substrate surface quickly reverted to PI by absorbing thermal energy during sintering. The increased contact area between Cu nanoparticles and the substrate surface of the interlocking structure could explain the dramatic improvement of the adhesion strength of the Cu electrode from 0 B to 5 B, which corresponds to the highest class of adhesion strength. In addition, the resistivity of the Cu electrode fabricated in this process was measured to be 2.5 times larger (4.17 μΩ·cm) than that of bulk Cu, which has not been achieved for printed Cu electrodes before. Our results could lead to new perspectives in the field of printed electronics.

Efficiency of ultrasound for degradation of an anionic surfactant from water: Surfactant determination using methylene blue active substances method

The removal of a surfactant from wastewater is usually difficult due to its toxicity and low biodegradability. The aim of this study was to apply sonoreactor for degradation of an anionic surfactant from aqueous solution. An ultrasonic bath with frequency of 130 kHz was used to investigate the effects of different operational parameters such as sonication time, initial concentration and power. In this study, experiments of linear alkylbenzene sulfonates solution were performed using methylene blue active substances method. Experiments were performed at initial concentrations of 0.2 , 0.5 , 0.8 and 1 mg/L, frequency of 130 kHz, acoustic powers value of 400 and 500 W, temperature of 18–20 °C and pH value of 6.8–7. This study showed that linear alkylbenzene sulfonates degradation rate was found to increase with increasing sonication time and power. In addition, as the concentration increased, the linear alkylbenzene sulfonates degradation rate decreased in the ultrasonic reactor.•Surfactants are one of the largest groups of pollutants which exist in almost all urban and many industrial wastewaters.•Ultrasonic reactors alone may not be useful for reducing completely complex wastewaters of high surfactant load.•Application of ultrasonic reactors in combination with other treatment processes including Ozone, UV irradiation, chlorination, Fenton, nanoparticles and H2O2 could be used as a pre-treatment unit in a sequential chemical and biological treatment process.

Potential Color Change Dynamics of Beneficial Use Sediments

ABSTRACT Berkowitz, J.F.; VanZomeren, C.M., and Priestas, A.M., 2018. Potential color change dynamics of beneficial use sediments. Sediment color is important in determining aesthetic and habitat suitability for beach nourishment projects; however, sediment derived from dredging operations must meet locally established color compatibility requirements (i.e. cannot be too dark). Often, potential sediment sources are close to meeting specified thresholds, and previous observations suggest that sediments may lighten over time following beach nourishment. This work seeks to characterize the degree of color change potential based on the removal of constituents affecting sediment color. Thus, a sequential chemical treatment was developed to examine color changes associated with the removal of carbonates, organic matter, and iron oxide coatings from sediments collected from eight U.S. Army Corps of Engineers dredging operations. The results show that Munsell values increased by an average of 1.0 unit (became lig...

Synergistic effect of nanotopography and bioactive ions on peri-implant bone response.

Both bioactive ion chemistry and nanoscale surface modifications are beneficial for enhanced osseointegration of endosseous implants. In this study, a facile synthesis approach to the incorporation of bioactive Ca2+ ions into the interlayers of nanoporous structures (Ca-nano) formed on a Ti6Al4V alloy surface was developed by sequential chemical and heat treatments. Samples with a machined surface and an Na+ ion-incorporated nanoporous surface (Na-nano) fabricated by concentrated alkali and heat treatment were used in parallel for comparison. The bone response was investigated by microcomputed tomography assessment, sequential fluorescent labeling analysis, and histological and histomorphometric evaluation after 8 weeks of implantation in rat femurs. No significant differences were found in the nanotopography, surface roughness, or crystalline properties of the Ca-nano and Na-nano surfaces. Bone–implant contact was better in the Ca-nano and Na-nano implants than in the machined implant. The Ca-nano implant was superior to the Na-nano implant in terms of enhancing the volume of new bone formation. The bone formation activity consistently increased for the Ca-nano implant but ceased for the Na-nano implant in the late healing stage. These results suggest that Ca-nano implants have promising potential for application in dentistry and orthopedics.