Surface Modification Of Nanostructures Research Articles

Enhanced carbon fiber interface with thermoplastics via nanostructure surface modification: failure, morphology and wettability analysis

Improving the fiber-matrix adhesion in thermoplastic composites remains a significant challenge due to the lack of chemical bonding between thermoplastics and common reinforcing fibers. This study investigates the effectiveness of carbon fibers enhanced with nanostructure surface modification for strengthening the interfacial adhesion to thermoplastic matrices. The fiber surface was modified with graphene nanoplatelets (GNP) through the facile coating method, and the apparent interfacial shear strength (IFSS) was determined by the single-fiber pullout test. GNP-coated fiber improved IFSS by 74% with neat high-density polyethylene (HDPE-Neat) and 28% with maleic anhydride-grafted HDPE (HDPE-8MA), while reduced by 27% with polyamide 6 (PA6) due to different failure mechanisms. Morphology, chemical, and wettability analysis were conducted on the nano-enhanced carbon fibers to quantitatively elucidate these findings on micro/nanoscale, combining machine learning-based image segmentation, X-ray photoelectron spectroscopy (XPS), and contact-angle measurements of intermittent beading on fibers.

Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution

Nanostructured surface modification was performed on the ultrafine-grained commercially pure titanium (UFG cpTi) using electrochemical anodization. The characterization of the morphology of the nanostructured surface obtained during different times of electrochemical anodization was done using scanning electron microscopy (SEM). The corrosion resistance of the materials was examined using the potentiodynamic method and electrochemical impedance spectroscopy (EIS), during which the electrochemical characteristics of oxide layers and the evaluation of the corrosion resistance of the mentioned materials were determined. These materials were exposed to a solution simulating conditions in the human body (artificial saliva solution) with a pH of 5.5 at a temperature of 37 ºC. The obtained results indicate the extensive influence of time, as a parameter of electrochemical anodization on the surface morphology. The electrochemical anodization of 60 minutes can lead to the creation of the nanotubular oxide layer on the UFG cpTi surface, while the electrochemical anodization of 30 and 90 minutes did not lead to the creation of the nanotubular oxide layer, but it is up to the surface modification of UFG cpTi. Electrochemical tests showed a slight increase in the corrosion resistance in a solution of artificial saliva after electrochemical anodization. Also, the electrochemical impedance spectra for anodized and non-anodized UFG cpTi show the characteristics of corrosion resistance, but the anodized UFG cpTi has better resistance to the oxide layer. It can be concluded that anodized UFG cpTi has better corrosion stability, but both non-anodized and anodized UFG cpTi show exceptional corrosion stability in simulated conditions of the human body, which makes them equally suitable for use in medicine.

Surface modification of Co3O4 nanostructures using wide range of natural compounds from rotten apple juice for the efficient oxygen evolution reaction

In this study, a new strategy has been produced to use a rotten apple juice as a source for the surface modification of Co3O4 nanostructures, giving rise to efficient electro-catalysts for driving oxygen evolution reaction (OER) at relatively low over potential. We have studied the morphology, chemical composition, and crystalline aspects of Co3O4 nanostructures using different analytical techniques. The Co3O4 nanostructures grown with rotten apple juice were observed with low impurity of Fe and P, surface modification, reduced particle size, high concentration of oxygen vacancies, defects and cubic phase of Co3O4. Furthermore, we have used the surface modified Co3O4 nanostructures for water electrolysis and noticed the significant performance towards OER in alkaline conditions. The electrochemical characterization revealed that the Co3O4 nanostructure prepared with 20 mL of rotten apple juice exhibits an overpotential value of 269 mV at 20 mA/cm2 current density. The charge transport resistance (Rct) at the interface was estimated around 118.9 Ω, confirming an excellent reaction kinetics on the Co3O4 nanostructures and highly supported efficient performance towards OER. The Co3O4 nanostructures prepared with 20 mL of rotten apple juice has shown an acceptable durability for 40 h, verifying the long-term use. The performance of Co3O4 nanostructures with apple juice could be attributed to high oxygen vacancies due to high density of Co2+ ions on the surface, impurities of Fe and P, reduced nanoparticle size, defects in the structures, and favorable chemical composition. At the end, surface modified Co3O4 nanostructures was observed as an outperformed electrocatalyst when prepared with rotten apple juice. Therefore, this can be used in diverse purposes including energy conversion and storage applications.

Silver nanoparticles modified ZnO nanocatalysts for effective degradation of ceftiofur sodium under UV–vis light illumination

Light-induced photocatalytic degradation of ceftiofur sodium (CFS) has been assessed in the presence of plasmonic zinc oxide nanostructures (ZnONSTs), like, ZnO nanoparticles, ZnO nanorods (ZnONRs) and ZnO nanoflowers (ZnONFs). Silver nanoparticles (Ag NPs) loaded ZnO nanostructures (Ag-ZnONSTs) are obtained through seed-assisted chemical reaction followed by chemical reduction of silver. The surface modification of ZnO nanostructures by Ag NPs effectually altered their optical properties. Further, the surface plasmonic effect of Ag NPs facilitates visible light absorption by ZnONSTs and improved the photogenerated electron and hole separation, which makes the ZnONSTs a more active photocatalyst than TiO2 (P25) nanoparticles. Especially, Ag-ZnONRs showed higher CFS oxidation rate constant (k' = 4.6 × 10−4 s−1) when compared to Ag-ZnONFs (k' = 2.8 × 10−4 s−1) and Ag-ZnONPs (k' = 2.5 × 10−4 s−1), owing to their high aspect ratio (60:1). The unidirectional transport of photogenerated charge carriers on the Ag-ZnONRs may be accountable for the observed high photocatalytic oxidation of CFS. The photocatalytic oxidation of CFS mainly proceeds through •OH radicals generated on the Ag-ZnONRs surface under light illumination. In addition, heterogeneous activation of peroxymonosulfate by Ag-ZnONRs accelerates the rate of photocatalytic mineralization of CFS. The quantification of oxidative radicals supports the proposed CFS oxidation mechanism. Stability studies of plasmonic Ag-ZnONSTs strongly suggests that it could be useful to clean large volume of pharmaceutical wastewater under direct solar light irradiation.

A Novel Nanostructured Surface on Titanium Implants Increases Osseointegration in a Sheep Model.

A nanostructured titanium surface that promotes antimicrobial activity and osseointegration would provide the opportunity to create medical implants that can prevent orthopaedic infection and improve bone integration. Although nanostructured surfaces can exhibit antimicrobial activity, it is not known whether these surfaces are safe and conducive to osseointegration. Using a sheep animal model, we sought to determine whether the bony integration of medical-grade, titanium, porous-coated implants with a unique nanostructured surface modification (alkaline heat treatment [AHT]) previously shown to kill bacteria was better than that for a clinically accepted control surface of porous-coated titanium covered with hydroxyapatite (PCHA) after 12 weeks in vivo. The null hypothesis was that there would be no difference between implants with respect to the primary outcomes: interfacial shear strength and percent intersection surface (the percentage of implant surface with bone contact, as defined by a micro-CT protocol), and the secondary outcomes: stiffness, peak load, energy to failure, and micro-CT (bone volume/total volume [BV/TV], trabecular thickness [Tb.Th], and trabecular number [Tb.N]) and histomorphometric (bone-implant contact [BIC]) parameters. Implants of each material (alkaline heat-treated and hydroxyapatite-coated titanium) were surgically inserted into femoral and tibial metaphyseal cancellous bone (16 per implant type; interference fit) and in tibial cortices at three diaphyseal locations (24 per implant type; line-to-line fit) in eight skeletally mature sheep. At 12 weeks postoperatively, bones were excised to assess osseointegration of AHT and PCHA implants via biomechanical push-through tests, micro-CT, and histomorphometry. Bone composition and remodeling patterns in adult sheep are similar to that of humans, and this model enables comparison of implants with ex vivo outcomes that are not permissible with humans. Comparisons of primary and secondary outcomes were undertaken with linear mixed-effects models that were developed for the cortical and cancellous groups separately and that included a random effect of animals, covariates to adjust for preoperative bodyweight, and implant location (left/right limb, femoral/tibial cancellous, cortical diaphyseal region, and medial/lateral cortex) as appropriate. Significance was set at an alpha of 0.05. The estimated marginal mean interfacial shear strength for cancellous bone, adjusted for covariates, was 1.6 MPa greater for AHT implants (9.3 MPa) than for PCHA implants (7.7 MPa) (95% CI 0.5 to 2.8; p = 0.006). Similarly, the estimated marginal mean interfacial shear strength for cortical bone, adjusted for covariates, was 6.6 MPa greater for AHT implants (25.5 MPa) than for PCHA implants (18.9 MPa) (95% CI 5.0 to 8.1; p < 0.001). No difference in the implant-bone percent intersection surface was detected for cancellous sites (cancellous AHT 55.1% and PCHA 58.7%; adjusted difference of estimated marginal mean -3.6% [95% CI -8.1% to 0.9%]; p = 0.11). In cortical bone, the estimated marginal mean percent intersection surface at the medial site, adjusted for covariates, was 11.8% higher for AHT implants (58.1%) than for PCHA (46.2% [95% CI 7.1% to 16.6%]; p < 0.001) and was not different at the lateral site (AHT 75.8% and PCHA 74.9%; adjusted difference of estimated marginal mean 0.9% [95% CI -3.8% to 5.7%]; p = 0.70). These data suggest there is stronger integration of bone on the AHT surface than on the PCHA surface at 12 weeks postimplantation in this sheep model. Given that the AHT implants formed a more robust interface with cortical and cancellous bone than the PCHA implants, a clinical noninferiority study using hip stems with identical geometries can now be performed to compare the same surfaces used in this study. The results of this preclinical study provide an ethical baseline to proceed with such a clinical study given the potential of the alkaline heat-treated surface to reduce periprosthetic joint infection and enhance implant osseointegration.

Chemically modified surface of silicon nanostructures to enhance hydrogen uptake capabilities

Hydrogen is an active substitute for current commercial fuels as a green energy source. However, the progress toward hydrogen economy is stalled due to a lack of efficient and economical storage systems usually restrained by the material used. Some specific issues still need to improve in recent practical hydrogen storage methods: low surface area, limited capacity to attract gas adsorbate, high-temperature medium for hydrogen desorption, and extreme reactivity towards Oxygen and air. The paper presents a study on the surface modification of silicon nanostructures (SiNSs) synthesized by chemical etching, followed by structure optimization to enhance the hydrogen storage capacity. The standard anodization method prepares porous silicon (PS) while metal-assisted chemical etching fabricates Si and Porous Si nanowires (PSiNWs) on Si and PS substrates. Morphological features like surface area and porous nature were evaluated using SEM, AFM, and BET to interpret the gas-surface interaction. The modified surface area and average roughness of SiNSs increase maximum to 437 m2 g−1 and 501 nm, respectively. The PS shows the highest gas-surface interaction (up to 86.6%) and surface energy due to uniform pore distributions and high surface area. The NMR and FTIR investigate the hydrogen termination on the surface, whereas TG-DSC indicates the desorption of surface hydrides at ∼290 °C. A rank matrix is constructed considering various adsorption-desorption and fabrication parameters to select optimized SiNS, whereas PS is selected as a suitable candidate for hydrogen storage.

Comparative Study of Nanostructured TiO2 and SLA Surface Modifications for Titanium Implants: Surface Morphology and in vitro Evaluation

Our work presents a comparative study of morphological characteristics and the osteogenic potential of MC3T3-E1 cells on different modified surfaces of titanium: nanostructured TiO2 with 20 and 100 nm nanotube diameter, and sandblasting and acid etching, commercially known as SLA. Nanostructured TiO2surface was prepared by anodizing of titanium plates, while SLA surface was provided by commercial supplier. Surfaces were characterized by SEM, EDS, AFM, and water contact angle measurements. In order to evaluate cell response,in vitrotests of MTT, alkaline phosphatase and staining with alizarin red were performed. From the results ofin vitro tests, 100 nm nanotubular surface showed lower levels of cell mineralization, differentiation and adhesion. In general, 20 nm TiO2nanotubular and SLA surfaces promoted similar response from osteoblasts. As a result, 20 nm nanotubular surface proved to be a possible alternative to SLA surface with potential for use in oral implantology market.

Concentration and carbon chain length effects of cationic surfactant in enzymatic production of cellulose nanostructures

This work evaluated the effect of cationic surfactants [cetyltrimethylammonium bromide (CTAB), tetradecyltrimethylammonium bromide (TDTAB), and dodecyltrimethylammonium bromide (DTAB)], and its concentration (0.03, 0.30, and 3.00 mM) on the production by enzymatic hydrolysis and surface modification of cellulose nanostructures (CNSs), from the one-step method. From FTIR spectra, changes and surfactant peaks and bands for modified CNSs compared to CNS were observed. For XRD results, the crystalline structure was more altered for CTAB and TDTAB, especially for higher concentrations, not changing cellulose’s crystalline structure. The surfactants affected colloidal stability, which CTAB promoted a higher shielding effect than DTAB and TDTAB, reducing the negative charges present in nanocellulose, while high concentrations lead to saturation of colloidal system, creating micelles and causing agglomerates. However, CNS CTAB showed smaller particle sizes for lower concentrations (90–100 nm), lower sugar production (50 µg g−1) for high concentrations, and cellulose nanocrystals obtaining. CNS DTAB and CNS TDTAB did not present statistical differences for particle size. Thermal stability was also affected. CNS DTAB presented the highest Tonset (250–254 °C) compared to CNS TDTAB and CNS CTAB. Thus, these results prove and suggest the possible application of these modified CNSs to develop nanocomposites with excellent dispersion, resulting in promising properties.

Iron Carbide Nanostructures: An Emerging Material for Tumor Theranostics

ConspectusIron carbide (IC) nanostructures have attracted intense interest in several energetic and magnetic-related fields due to their high saturation magnetization, desirable stability, and excellent catalytic activity. Due to their iron-based magnetic capacity and carbon-arising near-infrared light-responsive performance, IC nanostructures have been regarded as emerging materials for tumor theranostics in the past decades. They have been extensively explored in several tumor-related biomedical areas, such as magnetic targeting, magnetic resonance imaging, magnetic hyperthermia, photoacoustic tomography, and photothermal therapy. In view of the growing requirements for tumor theranostics, IC nanostructures need to be incorporated with other nanostructures to form the improved IC-based nanocomposites. The success of such a manufacturing process needs not only the deep understanding of the synthesis mechanism of IC nanostructures but also the functionality of IC nanostructures in tumor diagnosis and therapy, as well as the interaction between IC nanostructures and the specific tumor microenvironment. By forming IC-based nanocomposites, the application scope of IC nanostructures is expanded to some unexplored areas, expecting to discover new biological functionality. In this Account, we summarize the synthesis and surface modification of IC-based nanostructures, and their recent promising applications in tumor theranostics, aiming to provide some paradigms for designing IC-based nanocomposites and uncover the interactions between IC-based nanocomposites and biological systems.The great potential of IC nanostructures in tumor theranostics is promoted by understanding their stimuli-responsive behavior in the tumor microenvironment and incorporating them with other functional materials to construct IC-based nanocomposites. For diagnosis purposes, IC nanostructures are excellent contrast agents for magnetic resonance imaging and photoacoustic tomography. Their applications can be expanded to other diagnostic modalities by suitable design of IC-based nanocomposites, such as introducing silver sulfide for fluorescence imaging. For therapy purpose, IC nanostructures can kill tumor cells through magnetic hyperthermia and photothermal effect, as well as using Fenton reaction-generated toxic hydroxyl radical. Furthermore, they can act as targeting carriers for antitumor drugs, releasing the payload on-demand at tumor site for chemotherapy. In the end, we look at the challenges and possible research directions for IC nanostructures, hoping to provide inspiration for future investigation.

Conceptual Developments of Aryldiazonium Salts as Modifiers for Gold Colloids and Surfaces.

Modified colloids and flat surfaces occupy an important place in materials science research due to their widespread applications. Interest in the development of modifiers that adhere strongly to surfaces relates to the need for stability under ambient conditions in many applications. Diazonium salts have evolved as the primary choice for the modification of surfaces. The term "diazonics" has been introduced in the literature to describe "the science and technology of aryldiazonium salt-derived materials". The facile reduction of diazonium salts via chemical or electrochemical processes, irradiation stimuli, or spontaneously results in the efficient modification of gold surfaces. Robust gold-aryl nanoparticles, where gold is connected to the aryl ring through bonding to carbon and films modified by using diazonium salts, are critical in electronics, sensors, medical implants, and materials for power sources. Experimental and theoretical studies suggest that gold-carbon interactions constructed via chemical reactions with diazonium salts are stronger than nondiazonium surface modifiers. This invited feature article summarizes the conceptual development of recent studies of diazonium salts in our laboratories and others with a focus on the surface modification of gold nanostructures, flat surfaces and gratings, and their applications in nanomedicine engineering, sensors, energy, forensic science, and catalysis.

Effect of surface modification of WO3 nanostructures on the performance for p-Si/n-WO3 structure diodes

Tungsten oxide (WO3) nanostructures were prepared with different weight percentages of hydrochloric acid (10, 30 and 50 wt%) through the acid precipitation method and analyzed by structural, functional, optical, morphological, dc electrical, and p-Si/n-WO3junction diodes. The XRD results show the structure, phase, and particle size of WO3 samples. The FT-IR spectra reveal the functional groups present in the samples. The UV-Vis analysis shows the electron transition and the decreased bandgap of the WO3 nanostructures. The FESEM analysis elucidates the surface morphology of the samples. I-V characteristics of WO3 demonstrates the non-linearity conduct in forwarding bias condition. The p-Si/n-WO3 junction diode parameters like ideality factor (n) and barrier height (B) have been calculated using the J-V method. The better diode performance is obtained to the maximum weight percentage (50 wt%) of HCl, which is experimentally calculated.

Microstructure, interface, and nanostructured surface modifications to improve mechanical and tribological performance of electrodeposited Ni-W-TaC composite coating

In this study, the influence of codeposited TaC particles on the microstructure of NiW matrix was investigated. The microstructure was significantly influenced, and a thick amorphous interface between TaC and the matrix phase was observed. Similarly, further advanced surface modification treatment, ultrasonic nanocrystal surface modification (UNSM) technique, was applied to the Ni-W-TaC composite coating to investigate surface characteristics, mechanical, and tribological performance. Different characterization tools such as XRD, HRTEM, SEM, EDS, and surface roughness tests have been utilized to examine the microstructure, interface, and surface-related properties of NiW, Ni-W-TaC, and UNSM Ni-W-TaC composite coatings. The synergetic strength of TaC incorporation in the microstructure and nanostructured surface modification distinctly improved the microhardness (≈ 880 HV), with small indentation, of UNSM Ni-W-TaC coating. As a result, a reduction in the coefficient of friction (COF) (μ ≈ 0.1) under a 15 N load was obtained in UNSM Ni-W-TaC coating against a steel ball under dry lubrication conditions.

Carbon-based heterogeneous photocatalysts for water cleaning technologies: a review

Clean and accessible water for all has been defined by the United Nations as a major goal to promote sustainability in a planet with improved life quality. However, the growth of population and global industry processes are having a massive impact on the water quality. The presence of organic pollutants in water and wastewater, such as pharmaceuticals, organic dyes and by-products of industrial processes, is a major issue. Conventional wastewater treatments are still limited, and, consequently, it is crucial to design innovative cleaning technologies such as heterogeneous photocatalysis with nanomaterials. Here we review mechanisms and applications of carbon-based nanostructures for heterogeneous photocatalysis applied to water purification. In particular, we present recent developments in synthetic routes and surface modification of carbon nanostructures aiming at their use under visible light irradiation. As such, carbon-based nanostructures decorated with distinct phases have been investigated, such as semiconductor compounds and polyoxometalates. The photocatalytic efficiency of hybrid nanocomposite materials is attributed to improved light harvesting and reduced recombination of photo-generated charge carriers. Furthermore, the recovery of photocatalysts by using assisted magnetic separation is presented as a promising strategy of reusability.

Characterization of Optimized TiO2 Nanotubes Morphology for Medical Implants: Biological Activity and Corrosion Resistance.

BackgroundNanostructured surface modifications of Ti-based biomaterials are moving up from a highly-promising to a successfully-implemented approach to developing safe and reliable implants.MethodsThe study’s main objective is to help consolidate the knowledge and identify the more suitable experimental strategies related to TiO2 nanotubes-modified surfaces. In this sense, it proposes the thorough investigation of two optimized nanotubes morphologies in terms of their biological activity (cell cytotoxicity, alkaline phosphatase activity, alizarin red mineralization test, and cellular adhesion) and their electrochemical behavior in simulated body fluid (SBF) electrolyte. Layers of small-short and large-long nanotubes were prepared and investigated in their amorphous and crystallized states and compared to non-anodized samples.ResultsResults show that much more than the surface area development associated with the nanotubes’ growth; it is the heat treatment-induced change from amorphous to crystalline anatase-rutile structures that ensure enhanced biological activity coupled to high corrosion resistance.ConclusionCompared to both non-anodized and amorphous nanotubes layers, the crystallized nano-structures’ outstanding bioactivity was related to the remarkable increase in their hydrophilic behavior, while the enhanced electrochemical stability was ascribed to the thickening of the dense rutile barrier layer at the Ti surface beneath the nanotubes.

Boosting the cathode function toward the oxygen reduction reaction in microbial fuel cell using nanostructured surface modification

AbstractProduction of bioelectricity via microbial fuel cells (MFCs) may become an important source of energy in the near future due to the possibility of extracting electric current from a wide range of organic wastes. In this study, several nanostructures, such as platinum (Pt)‐reduced graphene oxide nanocomposite, graphene nanosheets, MnO2, and MnO2/RGO, were synthesized, characterized, and investigated as cathode catalysts for oxygen reduction reaction. The prepared catalysts were tested in a single‐chamber microbial fuel cell with anaerobic bacterial mixed culture. Power density produced from MFC closed circuit operation using the nanoengineered catalysts were about 68 times more than those obtained using the classical graphite electrodes. Moreover, there was a slight reduction of 5.8% in power density (from 170 to 160 mW/m2) when Pt nanoparticles were loaded on the RGO nanosheets compared to Pt/C cathode. By replacing the precious Pt catalyst with other nanomaterials, a significant reduction in power density was observed. For RGO‐based cathode, the MFC performance decreased by 31.1% (from 170 to 117 mW/m2) and the percent of reduction reached 48.5% (from 170 to 88 mW/m2) for MnO2‐based cathode MFC. However, in RGO/MnO2 nanocomposite cathode MFC, the percent of reduction in power density was 26.4% (from 170 to 125 mW/m2). It can be concluded that RGO nanosheets loaded with Pt nanoparticles is a starting point for finding an alternative economic and effective cathode.

Mixed solvent based surface modification of CuS nanostructures for an excellent photocatalytic application

A variety of high-quality, shape and size consistent nanostructures of copper sulfide (CuS) in the form of hierarchical architectures composed of intersecting nano-sheets have been fabricated via mixed solvent route. Copper chloride and thiourea have been utilized as precursors for copper and sulfur sources for each experimentation in the presence of a variety of mixed solvents to obtain various morphologies of CuS. The prepared products have been characterized by X-ray powder diffraction (XRD) and all of the synthesized products have been investigated to be the phase pure single crystalline. Scanning Electron Microscopy (SEM) revealed the well-ordered and isolated particles. The Energy Dispersive Spectroscopy (EDS) spectrum further proved that the obtained products in all of the synthetic processes don’t contain any kind of impurity. Ultraviolet– visible–near infrared (UV–vis–NIR) transmittance spectrophotometer has been utilized to ascertain the optical properties of the as prepared nanostructures. An extended U.V absorption in near-IR region, indicate the covellite phase of CuS. Most importantly, the synthesized nanostructures demonstrated an excellent photo-catalyst response in degrading highly concentrated rhodamine B (RhB) dye aqueous solutions under visible light irradiation along with an excellent reusability, suggesting a promising application in wastewater purification. The excellent photo-catalytic activity has been attributed to surface hierarchical structure with good absorbing and adsorbing properties, high visible light utilization and low electron hole recombination rate.

Influence of Annealing Temperature on Corrosion Resistance of TiO2 Nanotubes Grown on Ti–30Ta Alloy

With little success, researchers has been searching for alloys with elements such as tantalum to improve the long-term life of implants. The Ti–30Ta alloy presents an elastic modulus E = 69 GPa that is close to that of bone (E = 17–25 GPa) than Ti cp (E = 105 GPa). In addition, nanostructure surface modification influences cell behavior and antimicrobial activity. So, this study investigates the corrosion behavior of surface modification by TiO2 nanotube grown on Ti–30Ta alloy after anodization process in the electrolyte glycerol + NH4F 0.25% at 30 V, for nine hours without annealing and annealed in 450 °C, 530 °C and 600 °C (5 °C/min). The electrochemical behavior was evaluated by three electrodes cell. The counter-electrode of graphite, reference-electrode of saturated calomel electrode and working-electrode at electrolyte of 0.15 M NaCl + 0.03 M NaF, with pH = 6 for 8000 s. The scanned region ranged from −0.8 V to values up to 3.5 V with a sweep rate 0.166 mV/s. Potentiodynamic polarization curves were obtained with a potentiostat. The sample was characterized by scanning electron microscopy (SEM) imaging, X-ray diffraction analysis (XRD) and wettability with a contact angle goniometer. We concludes from the obtained results that all treatment surfaces are hydrophilic (&lt;90°). The surface covered with TiO2 nanotube crystallinity showed anatase phase after annealing at 450 °C, 530 °C and 600 °C; the exceptions were the anodized-without-annealing treatment and without-surface-modification alloys. The electrochemical behavior of the five groups investigated showed similar high resistance to corrosion solution under all conditions.

Ceramic Biologics for Bony Fusion-a Journey from First to Third Generations.

To provide information on characteristics and use of various ceramics in spine fusion and future directions. In most recent years, focus has been shifted to the use of ceramics in minimally invasive surgeries or implementation of nanostructured surface modification features to promote osteoinductive properties. In addition, effort has been placed on the development of bioactive synthetics. Core characteristic of bioactive synthetics is that they undergo change to simulate a beneficial response within the bone. This change is based on chemical reaction and various chemical elements present in the bioactive ceramics. Recently, a synthetic 15-amino acid polypeptide bound to an anorganic bone material which mimics the cell-binding domain of type-I collagen opened a possibility for osteogenic and osteoinductive roles of this hybrid graft material. Ceramics have been present in the spine fusion arena for several decades; however, their use has been limited. The major obstacle in published literature is small sample size resulting in low evidence and a potential for bias. In addition, different physical and chemical properties of various ceramics further contribute to the limited evidence. Although ceramics have several disadvantages, they still hold a great promise as a value-based graft material with being easily available, relatively inexpensive, and non-immunogenic.

Aggregation and thermal properties of nanostructured montmorillonite covered with mixed adsorption layers of cationic polyacrylamide and hazardous lead(II) ions

The aim of the study was to investigate the influence of nanostructured montmorillonite surface modification by the cationic polyacrylamide and the lead(II) ions on the thermal and aggregation properties of solid particles covered with mixed adsorption layers. The effects of cationic groups content in the polymeric macromolecules, the order of individual adsorbates addition, and lead(II) ions concentration were determined. Using spectrophotometry, potentiometric titration, microelectrophoresis, turbidimetry, DCS (Differential Centrifugal Sedimentation) and thermal analysis methods, the adsorption, electrokinetic, aggregation properties, as well as the thermal stability of studied montmorillonite—CT PAM—Pb(II) systems were established. It was shown that applied polymeric substance (soil flocculant) causes accumulation of lead(II) ions, which are hazardous at very low concentrations. Nevertheless, the chemical nature of these interactions may limit the bioavailability of this heavy metal for plants.

Integration of mesoporous ZnO and Au@ZnO nanospheres into sensing device for the ultrasensitive CH3COCH3 detection down to ppb levels

Surface modification of metal oxide nanostructures with noble metals has attracted significant attention of researchers because of their importance in gas sensing applications. In this regard, mesoporous zinc oxide nanospheres (ZnO NSs) were designed through a simple template-free solvothermal approach and successive anchoring of gold nanoparticles (Au NPs) onto it was achieved through a chemical process followed by thermal treatment. The synergistic effects of different Au NPs loadings onto the structure, surface morphology, element contents, as well as chemiresistive gas sensing activities of solvothermal-mediated ZnO NSs were examined thoroughly and discussed. Gas sensing studies demonstrated that the sensor based on Au@ZnO-3 NSs exhibits excellent acetone (CH3COCH3) sensing characteristics (Response = 194) compared to pristine ZnO NSs sensor (Response = 2.86) at a lower temperature of 170 °C. Besides, Au@ZnO NSs sensor is able to detect CH3COCH3 concentration down to ppb-levels (500 ppb) with excellent response repeatability. Observed CH3COCH3 sensing performances of all the Au loaded ZnO NSs sensors were found to be almost 50 times higher than pristine ZnO NSs sensor. Such an excellent CH3COCH3 sensing performance of Au@ZnO NSs is mainly credited to the catalytic activity of Au NPs and the strong metal-semiconductor contacts between Au NPs and ZnO NSs.