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In this research, graphene oxide (GO) functionalized with 3-amino-1, 2, 4-triazole-5 thiol (ATT) [fGO] has been synthesized for the achievement of a high protection performance of epoxy coatings with enhanced mechanical properties. A novel combination of fGO/epoxy composite coating will be a promising application for the corrosion protection of steel. The corrosion protection evaluation of fGO-grafted epoxy composite coatings on mild steel is investigated using electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM). EIS revealed high film resistance, charge transfer resistance and low capacitance for the fGO-grafted epoxy-coated mild steel. SECM analysis showed less current distribution (0.5–2.5 I/nA) at the scratched surface of fGO-grafted composite coatings compared to neat epoxy coatings (2–10 I/nA) on mild steel. The presence of sulfur and nitrogen atoms in the fGO facilitates the enhanced corrosion protection performance of epoxy-fGO-coated mild steel. Mechanical properties of the coatings were also found to be improved in the presence of modified GO particles as evidenced by hardness test and pull-out adhesion test. [ABSTRACT FROM AUTHOR]

Bioresorbable calcium phosphate-polymer composite implants are a desirable alternative to the traditional metal bone-healing devices. Incorporation of antimicrobial drugs into the composite material and their sustained delivery may dramatically reduce the risk of implant infections. The paper reports the fabrication of drug-incorporated bioresorbable CaP-polymer nanocomposites that can be used for fracture fixation devices and at the same time function as local delivery systems. Vancomycin was incorporated into β-tricalcium phosphate (β-TCP)- and biphasic CaP (BCP)-based composites containing ≤30 vol.% polycaprolactone (PCL) or polylactic acid (PLA), during their high pressure consolidation at 2.5 GPa and room temperature. The antibiotic release was studied in Tris buffer solution at 37 °C. Up to 5 wt% vancomycin could be included without compromising material's integrity upon immersion into Tris solution. Vancomycin release profile was found to depend on the specific surface area of the test specimens and on the composite porosity. β-TCP-30 vol.% PLA composites were found to have the best combination of compression strength and drug release pattern. Complete drug release was accompanied by only negligible material dissolution suggesting a diffusion mechanism of release. In the context of bone-healing applications, such a release-dissolution pattern will allow local prophylaxis against implant-related infection at the early stages after implantation followed by a much more slow dissolution of the load-carrying device. [ABSTRACT FROM AUTHOR]

Studies into bone-like apatite or hydroxyapatite (HA) growth on potential biomaterials when in contact with simulated body fluid (SBF) not only establish a general method for determining bioactivity but coincidently lead to the design of new bioactive materials in biomedical and tissue engineering fields. Previous studies of HA growth on porous silicon (PS) have examined electrochemically etched silicon substrates after immersion in a SBF. This study differs from previous work in that it focuses on characterising HA growth on chemically etched metallurgical grade nanoporous silicon particles. The PS used in this study is comprised of nanosponge particles with disordered pore structures with pore sizes ranging up to 10 nm on micron-sized particles. The silicon particles are analysed before and after immersion into SBF using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis and X-ray photoelectron spectroscopy (XPS). Results indicate that a HA layer forms on the surface of the nanosponge particles. Experimental analysis indicates that the morphology and calcium-to-phosphorus ratio (Ca/P) verify the formation of crystalline HA on the nanoporous silicon particles. [ABSTRACT FROM AUTHOR]

Dye-doped deoxyribonucleic acid–surfactant films have been prepared by an intercalation method and their optical properties have been investigated. Coumarin 1 (C1), known as a neutral laser dye, can be successfully incorporated in deoxyribonucleic acid-surfactant films by immersing them in aqueous dye solution. About 6 wt% C1 can be doped in samples when the immersion time is 86400 s. C1-doped samples show pronounced optical absorption and photoluminescence bands. Not only hydrophobic–hydrophobic interactions but also molecular structures of dyes play prominent roles in the formation of neutral dye-doped deoxyribonucleic acid-surfactant films. It is surmised that C1 stays inside the double helix of deoxyribonucleic acid (DNA) and/or between the alkyl groups of surfactants. [ABSTRACT FROM AUTHOR]

The effect of copper addition in the microstructure of sol–gel titanium oxide (TiO2) supported on anodic aluminum oxide (AAO) membranes is reported. Two deposition methods based on immersion and flow techniques were used for the coating of the porous AAO membrane. Copper-free membranes were studied as a function of different ratios of H+/Ti, H2O/Ti, selecting the most appropriate for the sensitization with copper. For copper-doped TiO2 arrays, the presence of copper causes the reduction of grain size and enhances titania deposition inside the AAO pores, although no clear tendency with copper content was found. The formation of copper-doped titania nanotubes was validated after dissolving the AAO membranes, finding a deposition-dependent stability in the Cu-doped materials. Titania and Cu-doped titania nanotubes analyzed as colloidal solutions show band gaps substantially shifted to the red in comparison to the direct band gap of near-spherical colloidal materials. These arrays are important for photocatalysis and for the development of third generation photovoltaic devices. [ABSTRACT FROM AUTHOR]

In this paper, an electrochemical (EC) method to activate 316L stainless steel (denoted as 316L) surface for biomimetic calcium phosphate (Ca–P) coatings was reported. After EC treatment, a gel-like Ca–P film with a thickness of 150 nm was generated on the stainless steel surface after treatment, which was composed of amorphous phase of calcium phosphate with a large number of crystal nuclei of octacalcium phosphate (OCP) inside. This Ca–P thin film is the main factor that causes Ca–P formation under biomimetic condition. The effectiveness of EC treatment was also compared with alkali heat (AH) pretreatment in producing biomimetic coating on 316L. A uniform Ca–P coating formed on EC treated samples after samples were immersed in saturated calcium solution (SCS) for several hours, while only some island-like deposits were found on the sample surface with AH treatment followed by immersion in SCS for several days. This work has explored a novel and effective pretreatment method to activate 316L implant surface, which can be expected to be applied to activate other metal implants. [ABSTRACT FROM AUTHOR]

Porous poly(D,L-lactide) PDLLA foams containing 0, 5 and 20 wt% of TiO2 nanoparticles were fabricated and characterised. The addition of Bioglass® particles was also studied in a composite containing 5 wt% of Bioglass® particles and 20 wt% of TiO2 nanoparticles. The microstructure of the four different foam types was characterised using scanning electron microscopy (SEM) and their mechanical properties assessed by quasi-static compression testing. The in vitro behaviour of the foams was studied in simulated body fluid (SBF) at three different time points: 3, 21 and 28 days. The degradation of the samples was characterised quantitatively by measuring the water absorption and weight loss as a function of immersion time in SBF. The bioactivity of the foams was characterised by observing hydroxyapatite (HA) formation after 21 days of immersion in SBF using SEM and confirmed with X-ray diffraction (XRD) analysis. It was found that the amount of HA was dependent on the distribution of TiO2 nanoparticles and on the presence of Bioglass® in the foam samples. [ABSTRACT FROM AUTHOR]

Soldering reactions are commonly observed during high pressure die casting of aluminium alloys, and involve the formation and growth of interfacial intermetallics between the die and the cast alloy. It is generally believed that close to 1% Fe is necessary in the aluminium alloy to reduce soldering. However, the role of iron in the interfacial reaction has not been studied in detail. In this investigation, reaction couples were formed between H13 tool steel substrates and an Al-11Si-2.5Cu melt containing either 0.15 or 0.60% Fe. Examination revealed distinctly different intermetallic layer morphology. The overall growth and chemistry of the reaction layer and the reaction rate measured by the consumption of the substrate were compared for the two alloy melts. It was demonstrated that a higher iron content reduces the rate of interfacial reaction, consistent with an observed thicker compact (solid) intermetallic layer. Hence, the difference in reaction rate can be explained by a significant reduction in the diffusion flux due to a thicker compact layer. Finally, the mechanism of the growth of a thicker compact layer in the higher iron melt is proposed, based on the phase relations and diffusion both within and near the interfacial reaction zone. [ABSTRACT FROM AUTHOR]

Zinc and its alloys have been given promising consideration as a new biodegradable implant for use in the human body. Compact and uniform nano hydroxyapatite coatings containing chitosan were successfully deposited onto zinc substrate in an aqueous solution utilizing microwave-assisted process in about 10 min. The quick composite coatings are derived by microwave heating compared with the coatings derived by electrodeposition. The as-deposited coatings formed by electrodeposition synthesis were known as brushite, which was converted to hydroxyapatite after 1 h of immersion (post treated) in 1 M aqueous sodium hydroxide solutions at 100 °C. The incorporation of chitosan (from 0.01–0.05 g/l) into the coating composition results in a smooth and uniform coating structure. SEM, EDS, and an X-ray diffractometer were utilized to analyze coated samples' surfaces to evaluate their surface morphology, chemical composition, and crystalline structures. The in vitro degradation behavior of the composite-coated samples in simulated body fluid at pH 7.4 and 37 °C was evaluated using electrochemical impedance spectroscopy and potentiodynamic polarization. The outcomes showed that microwave-derived coatings provided superior corrosion resistance for zinc implants as compared to electrodeposited coatings. Furthermore, the use of chitosan in hydroxyapatite coatings increased electrochemical corrosion performance. Low chitosan concentrations (0.01–0.03 g/l) exhibit superior anti-corrosion properties than higher concentrations (0.05 g/l). Against Staphylococcus aureus, the coatings demonstrated strong antibacterial efficacy. These corrosion outcomes and the fruitful deposition of a hydroxyapatite/chitosan composite coating on zinc substrate indicate that the coating is efficient for the creation of new composite coatings for either functional implants or regenerative medicine. The resultant coating may be an excellent option for bone implants. [ABSTRACT FROM AUTHOR]

Presents some physical properties of the zinc telluride (ZnTe), one of group II-VI semiconductors, doped with copper (Cu) by immersion in Cu(NO3)2-H2O solution and examines the effect of immersion time and subsequent heating in vacuum on the preparation of such films. Deposition of ZnTe thin films on a soda lime glass substrate; Sublimation of the ZnTe material from a graphite source; Use of mica sheet as an insulator between the source and the substrate.

In a new approach combining additive manufacturing with bioceramics, a metallic 3D porous structure coated with bioactive glass was produced for possible use in orthopedic implants. This approach aims to combine high mechanical properties of the metallic structure with enhanced biological activity. 316L stainless steel (316L-SS) lattice structures were fabricated using selective laser melting. Despite its good mechanical properties, 316L-SS lacks the biofunctionality required to achieve long-term implantation. To be successfully used as biomaterial, these porous 3D lattice structures were thus coated by 58S bioglass through a simple impregnation method. The use of a silica layer was evaluated as possible pretreatment to improve bioglass adhesion. The coated parts are then assessed by scanning electron microscopy coupled with energy-dispersive spectrometry to qualify the coating. Porous sample parts pretreated with a silica layer presented a denser coating structure when compared with untreated porous metallic structures. The bioactivity in SBF medium shows the formation of a uniform apatite layer after 7 days of immersion, producing the bioregeneration capability. This latter, combined with the lightweight framework structure provided by 316-SS, will increase the lifetime of this new generation of orthopedic implants. [ABSTRACT FROM AUTHOR]

Ideal inorganic bone cement used for bone repair should have high strength, and the speed of degradation should match the formation rate of new bone tissue. Magnesium oxychloride cement has excellent mechanical properties and non-toxicity to bone marrow stromal cells; however, its application has been hindered by its poor water resistance. In this study, the high-degradation material chitosan (CS) was added to magnesium oxychloride cement (MOC). The compressive strength, mass loss, ion release, and pH value of the composite MOC were analyzed and scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were conducted. The compressive strength was 45.4 ± 5.3 MPa in cements with 0.5-wt% CS and 2-wt% KH2PO4 soaked in SBF for 28 d, and the degradation rate reached 12.67 ± 0.5%. SEM observations showed good apatite formation of the surfaces of the MOC with 2-wt% KH2PO4 and with 0.5-wt% CS and 2-wt% KH2PO4. The results indicate that the modified MOC possesses good mechanical properties, degradation rate and biological properties. Therefore, it is a promising material for degradable bone filling. [ABSTRACT FROM AUTHOR]

Flame-retardant and superhydrophobic coatings over cotton fabric are fabricated by solution immersion method using green-based flame retardants, i.e. DNA, silver nitrate and octadecyltriethoxysilane are used to get flame-retardant cotton with superhydrophobic nature. The results of this work showed that the as-prepared cotton fabric with a maximal contact angle of 157° was obtained and surfaces before and after were characterised by scanning electron microscopy, X-ray photoelectron spectroscopy and FT-IR studies. Some typical flame tests and TGA/DTG studies were done to evaluate the flame retardant property and thermal stability of the coated cotton samples. These results demonstrated that solution immersion strategy is a relatively simple and convenient method to fabricate superhydrophobic and flame-retardant cotton fabric. [ABSTRACT FROM AUTHOR]

Advanced materials can be developed by the combination of synthetic polymer and nanomaterial for biomedical application. Polypyrrole/graphene oxide (PPy/GO) composite coating on Ti metal was developed through electropolymerization of pyrrole by varying the amount of GO in aqueous oxalic acid solution. The influence of GO in the PPy matrix was confirmed by scanning electron microscopy studies. Structural interactions between PPy and GO in the composite coating were studied using ATR-FTIR, solid 13C NMR and Raman spectroscopy. The higher surface roughness and the lower wettability of the composite-coated Ti favor biocompatibility. The increase in adhesion strength of the composite coating was analyzed by the cross-hatch adhesion test. Potentiodynamic polarization studies showed a higher polarization resistance (Rp) and lower corrosion rates for composite coatings. Dynamic electrochemical impedance spectroscopy studies confirmed the PPy/GO composite coating exhibited a higher impedance from − 0.55 to 1.25 V in SBF solution. Bode impedance and Bode phase angle results revealed a higher resistance for PPy/GO composite-coated Ti. Immersion studies of PPy/GO composite coating in SBF solution revealed the growth of dense hydroxyapatite (Hap.) over Ti metal. Further, in vitro cell culture studies were carried out by MG-63 cells to assess the biocompatibility of PPy/GO composite coating on the substrate. Improved corrosion protection and biocompatibility behavior of PPy/GO composite-coated Ti suggests the potential candidate for biomedical applications. [ABSTRACT FROM AUTHOR]

Here, we investigate the effect of high-pressure torsion (HPT), a severe plastic deformation process, on the mechanical properties, corrosion, and cytotoxicity of Mg–6Zn–0.2Ce alloy, a candidate material for bioresorbable bone implants. This alloy was processed by quasi-constrained HPT by applying a pressure of 6 GPa at room temperature for 1, 2, and 5 turns. Samples processed to two turns of HPT showed the smallest grain size, the highest strength that was approximately five times higher than the as-received coarse-grained sample and a reduction in the ductility. Electrochemical impedance spectroscopy and potentiodynamic polarization demonstrated the highest corrosion resistance for the Mg-alloy processed for two turns of HPT; however, accelerated degradation due to pitting corrosion was observed after immersion in simulated body fluid for 3 days. Nevertheless, all HPT-processed samples showed lower corrosion rates in all corrosion tests compared to their annealed counterparts. Finally, cell culture revealed good cytocompatibility without any noticeable changes in cytotoxicity following HPT processing. Overall, HPT for two turns showed enhanced strength and reduced corrosion rates without loss in cytocompatibility for the Mg–6Zn–0.2Ce alloy, making it a promising strategy to enhance the performance of the alloy as a bioresorbable orthopedic biomaterial. This work highlights the potential of HPT as a viable technique to improve the biomedical performance of Mg alloys for engineering next-generation biomedical implants. [ABSTRACT FROM AUTHOR]

Electromagnetic radiation pollution has become increasingly serious in the electronic, industrial, civil, and military fields. Lightweight, flexible, and high-performance electromagnetic shielding films have recently become popular research topics. Herein, regenerated cellulose (RC) was used as the matrix, multi-walled carbon nanotube (MWCNTs) and Fe3O4 nanoparticles were used as fillers, the sandwich-structured composite films (SCFs) containing MWCNTs/RC film as the surface layer and Fe3O4/RC film as the interlayer were successfully prepared via immersion phase conversion and mechanical pressing methods. SCFs exhibited a conductivity of 2.0 S m−1 and an excellent electromagnetic interference shielding effectiveness of 25.6 dB, which were 147% and 32% higher than those of the monolayer composite films at the same filler contents, respectively. The shielding mechanism was mainly attributed to electromagnetic dual energy dissipation and a "reflection–absorption–reflection" effect of the sandwich structure on electromagnetic waves. In addition, the maximum tensile strength of SCFs reached 18.0 MPa, which was attributed to the addition of MWCNTs and the construction of the sandwich structure. [ABSTRACT FROM AUTHOR]

Recent progress in the development of MnO2-based micromotors has shown the immense potential of these motile devices to remediate environmental contamination. However, the production of such micromotors on an industrial scale through a facile, efficient and reproducible process remains challenging. The present work aimed to address this issue using naturally occurring and abundant pine pollen (PP) grains. The immersion of PP in potassium permanganate (KMnO4) solutions was found to generate MnO2 nanoparticles (NPs) on the PP surfaces, the amount and distribution of which was readily adjusted by varying the coating time. Because of the asymmetrical shape of the PP grains, the MnO2/PP composites exhibited rapid self-propulsion at a maximum speed of 360.686 μm/s (approximately eight body lengths/s) in low-concentration hydrogen peroxide (H2O2) solutions. The ability of these materials to remediate heavy metal pollutants was also examined and was evidently increased by a factor of 1.5 compared with static counterparts. These composites could also be recovered and reused over three consecutive cycles. The competitive cost, continuous motion and superior decontamination capacity of these materials suggests potential applications in the rapid removal or degradation of heavy metal ions, toxic organic dyes, pathogenic bacteria and other pollutants in wastewater. These micromotors represent a new approach to the utilization of natural materials in environmental remediation. [ABSTRACT FROM AUTHOR]

NiCoCrAlYTa coating of the Ni-based superalloy substrate was processed using a feasible remanufacturing method. The coating was deposited using arc ion plating (AIP) and removed by a complex treatment of immersion-etching in hydrochloric acid solution and wet sandblasting. The conventional and remanufactured coatings were homogenized in vacuum at 1080 °C for 4 h and then oxidized isothermally in the air at 1050 °C for 200 h. The constituent phases and the microstructure were characterized using powder X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Additionally, the mechanical performance of the coated specimens was evaluated via tensile testing at room temperature and stress rupture testing at 982 °C/220 MPa. The complex treatment is found to effectively remove the NiCoCrAlYTa coating without causing damage to the substrate. The re-coated specimens had a tensile yield strength greater than 985 MPa at room temperature, a rupture life of 45 h at 982/220 MPa, and an oxidation rate constant Kp of 3.16 × 10–12 g2cm−4 s−1 at 1050 °C, which were nearly identical to those of the conventionally coated specimens. [ABSTRACT FROM AUTHOR]

With the increase in environmental protection requirements, the oil in the wastewater from offshore oil wells or industries has to be removed with high-precision before discharge. However, the oil-in-water emulsion with high stability is intractable, which makes the oil removal a great challenge. Herein, we designed a novel approach to fabricate carbon fiber cloth with cutting effect that can separate oil-in-water emulsion efficiently. Carbon fibers were firstly modified by ZIF-8 nanoparticles through a hydrothermal method, which induced an ultrafast growth of vertical zinc blades during subsequent electrodeposition (100 s). The blade-like Zn nanosheets on carbon fiber cloth (B-Zn/CFs) were assembled into a superhydrophilic/underwater superoleophobic hierarchical structure, which have the capability of rupturing oil-in-water emulsion via unique cutting effect of the zinc blades. High separation efficiency of 99.72% with exceptional emulsion flux of 962.95 L m−2 h−1 bar−1, and remaining above 98.53% after 10 cycles were achieved over the composite materials. In addition, the underwater superoleophobic property of B-Zn/CFs persisted even after ultrasonic treatment and salt solution immersion. It is demonstrated that the composite materials show excellent recyclability, mechanical stability and environmental stability during oil/water separation. This work provides a new pathway to design functional materials for high-precision oil removal from wastewater. [ABSTRACT FROM AUTHOR]

This paper focuses on investigating and comparing the effects of CuO and FeO addition on the bioactive response of glass having composition [ xCuO or FeO + (100 − x) (0.2CaO + 0.2SrO + 0.1NaO + 0.5PO)] (in mol%), where x is ranging from 0 up to 5. The addition of CuO was found to increase the hot processing window and the dissolution rate leading to a fast surface layer precipitation. Using IR and Raman spectroscopies, we related this change in the bioactive response of this glass to the progressive depolymerization of the glass network induced by the addition of CuO. On the other hand, the addition of FeO was found to reduce the hot processing window and the dissolution rate as no depolymerization of the network occurs due to the formation of P-O-Fe bonds at the expense of P-O-P bonds. All the glasses were found to dissolve congruently and in a controlled manner. Finally, the antimicrobial properties of the copper-doped glasses were examined and compared to bioactive glasses which are known to exhibit good antimicrobial properties. The CuO addition leads to higher antimicrobial properties than the commercial bioactive glass S53P4 and total bacterial elimination could be obtained. [ABSTRACT FROM AUTHOR]

An emerging topic in the field of biomaterials is the incorporation of silver ions, metallic silver or silver oxides into bioactive glasses to impart novel functionalities. In this work, a new approach of surface functionalization of 45S5 bioactive glass (BG) is introduced. In contrast to more common methods, which are based on the inclusion of silver during the sol-gel synthesis of BG, our method allows the surface functionalization of BG powders and BG scaffolds after their preparation. Hereby, we demonstrate the transferability of a previously reported approach on the wet chemical synthesis of cup-like and dendritic silver patches first from colloidal silica particles to BG particles and further to macroscopic highly porous BG scaffolds which were prepared by the sacrificial foam replica technique. The time-dependent silver releases of BG scaffolds with different silver loadings into simulated body fluid (SBF) were measured. Further studies were addressed to investigate the bioactivity of BG scaffolds before and after the silver coating procedure. It was found the silver deposition on 3D BG scaffolds did not affect the formation of crystalline hydroxyapatite during immersion into simulated body fluid. [ABSTRACT FROM AUTHOR]

Aside its historical use in contact with bone and teeth, an increasing number of studies use bioactive glasses (BG) in contact with soft tissue. BG could provide solutions for various medical problems. This study presents a first evaluation, whether BG containing silicone elastomers are a suitable material for left ventricular assist device drivelines and could enhance skin biointegration thereof. Three different nano- or microparticles of BG45S5 were incorporated into medical grade silicone elastomer, and thin films of the composites were manufactured. Physicochemical, mechanical and in vitro experiments using primary human dermal fibroblasts were used to evaluate the nano- and microcomposites. The incorporation of BG particles reduced the tensile strength at break and percent elongation at break of the composites and increased the stiffness of the material. Especially, the incorporation of nanosized BG decreased the percent elongation at break after immersion in SBF due to agglomerate formation and increased hydroxyapatite formation compared to commercially available microparticles. The cytocompatibility of BG containing composites increased significantly with increasing particle concentration. A clear trend regarding particle size was not observed. In general, the simple incorporation of particles into medical grade silicone elastomer allowed an easy modification of the mechanical properties and improvement in bioactivity (assessed by hydroxyapatite formation) of the material. The choice of either nano- or microparticles depends on the specific application and requirements for the material, as different particle types show different advantages and disadvantages. [ABSTRACT FROM AUTHOR]

Constant immersion testing and slow strain rate testing (SSRT) are conducted on wrought magnesium alloy in a 3.5 wt% NaCl solution. After solution annealing (SA) at 525 °C for 8 h, the alloy was isothermally aged at 210 °C for 15 h, 48 h, and 144 h to obtain underaged (UA), peak-aged (PA), and overaged (OA) microstructures, respectively. After 32 days of constant exposure in chloride solution, the SA and UA samples showed the lowest (~ 0.10 mg cm−2 day−1) and the highest (~ 0.20 mg cm−2 day−1) weight loss, respectively. SSRT was carried out at an initial strain rate of 10−6 s−1 in air and 3.5 wt% NaCl solution to investigate stress corrosion cracking (SCC) susceptibility. SCC susceptibility index was in the order PA > UA > SA > OA. Intergranular failure morphology on the fractured surface after SSRT in chloride solution can be attributed to micro-galvanic activity between grain boundary second phase and adjacent regions. Comparison of electrochemical measurements in unstressed and stressed conditions indicated two orders of magnitude difference in electrochemical resistance of the alloy. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA)-based composite reinforced with magnesium alloy wires (Mg wires) is prepared by lamina stack method for orthopedic implants. The impact behaviors of the composite are experimentally and theoretically studied. The results suggest that Mg wires could significantly improve the impact performances of PLA. The initial impact strength of the composite with 10 vol% Mg wires is about 5 times that of pure PLA. After 3 weeks, immersion at 50 °C, the impact strength of the composite at 10 vol% could retain to be 10 kJ/m2, while pure PLA losses its impact strength. Further theoretical studies by finite element method indicate a small diameter for the wires could significantly improve the impact properties of the composite and promote the energy absorption of the wire components. Moreover, increasing the lamina numbers could also improve the impact properties of the composite. [ABSTRACT FROM AUTHOR]

Glasses with composition (ZnO)(MgO)(PO) ( x = 5, 8, 10, 13, 15, 18, and 20 mol.%) have been successfully prepared by the melt-quenching technique. Degradation study has been carried out by means of measuring their chemical durability against buffer solutions with initial pH values of 4.01, 7.00, and 10.01 at an ambient temperature for up to 30 days. The dissolution rate ( D) was obtained by calculating the measured weight loss of the glasses per unit surface area per unit immersion time. The results show that the glasses have better corrosion resistance in basic solution. It was also found that the weight loss is related to the MgO concentration with lower PO concentration exhibiting greater corrosion resistance irrespective of acidic, neutral, or basic solutions as immersion liquid. All the sample surfaces and edges were corroded and the solutions experienced a decrease in pH values during the duration of the corrosion test. [ABSTRACT FROM AUTHOR]

Electrochemical impedance spectroscopic characterization of the low modulus Ti-35.5Nb-7.3Zr-5.7Ta alloy has been performed in phosphate buffer saline solution at 37 °C. Measurements were performed at various immersion intervals up to 720 h at OCP and also at various anodic potentials up to 2 V. The alloy exhibits a two time constant impedance response at the OCP and a one-time constant response at anodic potentials in the passive region. The thickness of the oxide film formed has been evaluated and the electrochemical interpretation of the results has been reported. Cyclic potentiodynamic profile of the alloy displays valve metal characteristics and the presence of a wide passive region that extends up to the maximum potential value of 2 V studied. [ABSTRACT FROM AUTHOR]

This study investigated the hydroxyapatite (HA) coating on metal implants in order to enhance their bioactive properties. In this study, HA coatings were formed on the surfaces of commercially pure titanium (c.p. Ti) and Ti–7.5Mo which were acid-etched and subsequently alkali-treated before samples were soaked in simulated body fluid (SBF). Specimens of c.p. Ti and Ti–7.5Mo were etched in either H3PO4 or HCl, and subsequently treated in NaOH. The surfaces of acid-etched c.p. Ti showed a porous structure, whereas those of acid-etched Ti–7.5Mo showed some grinding marks, but no porosity. After subsequent alkali treatment in NaOH, the surfaces of both the c.p. Ti and Ti–7.5Mo substrates exhibited microporous network structures. The specimens were then immersed in SBF at 37 °C for 28 days. Apatite began to deposit on acid-etched and NaOH-treated Ti–7.5Mo within 1 day after immersion in the SBF. After 28 days of immersion in the SBF, a dense and uniform layer was produced on the surfaces of all samples. The HA formation rate was the highest for HCl and NaOH-pretreated samples, and the results of EDS and XRD showed that much more intensive peaks of HA appear on the specimens of HCl and NaOH-treated Ti–7.5Mo than on any other sample. Thus, this method of apatite coating Ti–7.5Mo appears to be promising for artificial bone substitutes or other hard tissue replacement materials with heavy load-bearing applications due to their desirable combination of bioactivity, low elastic modulus, and low processing costs. [ABSTRACT FROM AUTHOR]

In this study, the corrosion behavior of Mg–5Al alloys with different quantities of calcium was investigated by DC and AC polarization and immersion tests. The alloys’ microstructure was investigated by optical microscopy and SEM with EDS. It was found that increasing the Ca content from 0.9 to 1.8 wt% improves the corrosion resistance of the alloy; the corrosion resistance of the alloy with 1.8 wt% Ca equals that of the base Mg–5Al alloy. Ca addition causes a reduction of the average grain size, which increases corrosion resistance as the precipitates located at grain boundaries are more continuous and act as a barrier to the advance of corrosion. The precipitates located at grain boundaries contain Al and Ca and are much less cathodic than the β phase, thus making the microgalvanic effect in the specimen less effective. [ABSTRACT FROM AUTHOR]

Presents a correction to two figures published in the July 2005 issue of the "Journal of Materials Science."

Recent surge of thermal stable polymeric separators for LIBs has demonstrated potential success by utilizing phase inversion approach. However, via phase inversion, there are typically two types of morphologies, the finger-like and sponge-like, whose impact to the performance of the LIBs at high temperature has not yet been analyzed. In this paper, we attempted to clarify the importance of the morphology of a thermal stable PEEK separator in LIBs. Both finger-like (F-PEEK) and sponge-like (S-PEEK) structure were prepared via immersion precipitation and vapor-induced phase separation. Furthermore, a sponge-like structure with high pore connectivity was realized by addition of polyvinyl pyrrolidone (PVP) (S-PEEK/PVP). The intrinsic thermal resistance of PEEK attributes separators with dimension stability at 180 °C. Comparing to F-PEEK and S-PEEK, S-PEEK/PVP separator showed excellent electrolyte uptake, high porosity, high ionic conductivity (1.65 mS cm−1) and good electrochemical stability up to 5.5 V. Inferior performance of S-PEEK separator was probably caused by the low pore connectivity. At 45 °C, S-PEEK/PVP separator incorporated LIBs showed higher discharge capacity and better cycle property than LIBs with S-PEEK, F-PEEK and PP separators. Autopsy of failed LIBs with F-PEEK showed collapse of finger structure. For S-PEEK/PVP separator, intact anode material attributed to a capacity retention rate 97.9% after cycling for 150 cycles. The results indicated the importance of the sponge-like morphology for preparing the thermal stable separators for LIBs via phase inversion method. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials have a comprehensive application in anti-corrosion coatings as nano-packing due to their large diameter/thickness ratio and wonderful barrier performance for water and oxygen. However, some disadvantages restrict the introduction of 2D materials into polymer matrix, including complicated preparation and modification processes, high costs, etc. In this study, an environment-friendly melamine phytate (PM) nanosheets were prepared and then introduced into the polymer matrix without any modification for fabricating water-borne epoxy (WEP) composite coatings. Long-term electrochemical test shows that 1.0 wt% PM/WEP exhibits the best anti-corrosion performance: highest log |Z| at 0.01 Hz value (7.8 Ω cm2) and lowest Icorr (2.83 × 10–9 A cm−2), and the minimum corrosive iron content in corrosion products after film remove (the oxygen and chlorine contents are 4.66% and 0.05%, respectively). These results reveal that proper addition of PM nanosheets could extremely improve the anti-corrosion performance in composite coatings. This research provides a mentality for the large-scale application of 2D materials into polymer coatings. PM nanosheets were prepared by hydrothermal process which using melamine (MA) and phytic acid (PA), two green and eco-friendly raw materials. And then the nanosheets were firstly introduced into water-borne epoxy resin (WEP). On the lower right, it is a scanning electronic image (SEM) of PM nanosheets. To the lower left, it is the corrosion protection between blank WEP, 0.5 wt% PM/WEP, 1.0 wt% PM/WEP and 1.5 wt% PM/WEP coatings. [ABSTRACT FROM AUTHOR]

Double-layer ZnO containing nanoflakes and nanorods was prepared on aluminum foil by a simple one-step hydrothermal method. The aluminum foil coated with double-layer ZnO could form a slippery liquid-infused porous surface (SLIPS) by immersing the sample in an ethanol solution containing stearic acid and then in Dupont Krytox 104. The as-prepared SLIPS had a larger contact angle and a smaller sliding angle. The electrochemical measurements showed that SLIPS presented higher and more durable corrosion resistance in comparison with the bare aluminum sample (BS) and the superhydrophobic surface (SHS). These results may enhance an alternative to design SLIPS for corrosion protection of metallic surfaces. [ABSTRACT FROM AUTHOR]

Flexible porous materials have been widely used as precursors for preparing superhydrophobic oil absorbents due to their high capacity and extraordinary recyclability. A final product with multiple characteristics such as superhydrophobicity, fire retardancy, good elasticity, low cost, and environmental friendliness is highly needed for practical applications. In this study, superhydrophobic melamine sponges (SMSs) with the above characteristics were prepared by modifying melamine sponges with polymethylsilsesquioxane via an immersion method. A villiform layer of organosilane was coated on the surface of the melamine fibers and disclosed by scanning electron microscopy. The superhydrophobicity of the sponge with a water contact angle of 156° is due to the increased surface roughness and methyl terminal groups exposed at the interface. Polycondensation reaction between the secondary amine groups on the raw sponge surface and silanol is identified by ATR-FTIR and EDX spectra. The SMS effectively absorbs various organic solvents and oils from water with excellent absorption rate. In addition, it maintains stable superhydrophobicity in extreme environments, including strong acid/alkali conditions, high/low temperatures, and prolonged immersion in organic solvents. Importantly, the SMS retains the intrinsic fire retardancy of the raw melamine sponge. In simulating oil spill environments, the SMS shows good performance in blocking spread of crude oil spill and separating surfactant-free water-in-oil emulsions. These advantages make it a promising material for oily wastewater treatment and oil spill clean-ups. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the influence of fluoride-containing solutions on the translucency of flowable composite resins, with respect the immersion time. Flow-It! (FI) and Natural Flow (NF) composite resins and three commercial brands of fluoride-containing solutions (Fluordent, Fluorgard and Oral B) were used. Specimens were prepared and stored in the solutions at 37°C, until the measurements were made after the following treatments: T1 - after 1 hour in relative humidity; T2 - after 1 h in solution; T3 - 24 h; T4 - 48 h; T5 - after a week; from T9, the measurements were accomplished weekly, up to 30-day immersion. To obtain translucency values an electrophoresis equipment was employed. Data were submitted to ANOVA and Tukey tests. The results disclosed that NF showed highest values of translucency and was statistically different from FI (p < 0.001). As regards the solutions, Fluordent and Oral B presented similar values and were statistically superior to Fluorgard (p < 0.05). Concerning the immersion time, similar results were observed for the different evaluation periods. It may be concluded that the fluoride-containing solutions affected the translucency of the composite resins, independently of the materials used. Among the tested resins, NF presented the best performance. [ABSTRACT FROM AUTHOR]

The GO-AMTT/TiS2 nanofiller was developed by combining surface-modified titanium disulphide (TiS2) with graphene oxide (GO) and 2-amino-5-methylthio-1H-1,2,4-triazole (AMTT), and it was subsequently incorporated into the epoxy resin (EP) to produce EP-GO-AMTT/TiS2 nanocomposite. Using electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM), the performance of epoxy coating on mild steel as a barrier against different concentrations of GO-AMTT/TiS2 in naturally occurring seawater was evaluated. It was found that that epoxy coating with 0.6 weight percent of GO-AMTT/TiS2 nanoparticles exhibited the highest resistance after exposed to seawater for 1 h. The limiting oxygen index test and thermogravimetric analysis revealed that the GO/AMTT-TiS2 significantly improved the flame retardancy properties of the epoxy coating. The peak heat release rate and total heat release values for the EP-GO/AMTT-TiS2 significantly decreased by 74% and 66%, respectively, as compared to pure EP, showing that the material is more flame retardant. The EIS experiments showed that the EP-GO/AMTT-TiS2 nanocomposite had increased coating resilience even after 960 h of submersion in seawater. According to SECM investigations, a small amount of ferrous ions was released at the scribe area of the EP-GO/AMTT-TiS2 coating. This is because the coated substrate is more resistant to anodic dissipation than the uncoated substrate. The developed EP-GO/AMTT-TiS2 coating has higher protective and hydrophobic (WCA: 157°) characteristics. The epoxy matrix's adhesive properties were enhanced by the addition of GO/AMTT-TiS2. Therefore, an EP-GO/AMTT-TiS2 nanocomposite may be employed in an industrial coating. [ABSTRACT FROM AUTHOR]

Akermanite (Ak) has promising prospects as an innovative bio-ceramic for bone regeneration. The most common fabrication methods to produce pure Ak powders are long-lasting synthesis routes followed by calcination at high temperatures. This study focuses on the use of microwave irradiation of a solution to provide initial Ak-based powder product that after subsequent heat treatment changes to pure Ak powder. The novel process named microwave-assisted sol–gel method actually speeds up the initial and final stages of pure Ak powder production when compared to the traditional sol–gel with later heat treatment stage. The viscous solution containing magnesium nitrate hexahydrate, calcium nitrate tetrahydrate, and tetraethyl ortho-silicate was microwave irradiated for three minutes. X-ray diffraction showed that the microwaved products after calcination treatment at 1200 °C for 4 h were mostly made of Ak and a small amount of merwinite. However, by increasing the calcination treatment to 1300 °C, single-phase akermanite powder was achieved. By subjecting same precursor and subsequent heat treatments, the typical sol–gel method did not yield pure Ak powder. Thermal analyses and scanning electron microscopy examinations showed that the Ak crystallization temperature was lower in the case of the microwave irradiated product than in the conventional sol–gel route. The microwave irradiated product after calcination showed a porous structure formed by necking between the powder particles with a mean particle size of 2 µm. The results of the in vitro bioactivity evaluation indicated that synthesized Ak was bioactive through proving the formation of hydroxyapatite (HAp) on the surface of pure Ak disc after 7 days of immersion in simulated body fluid (SBF). The cell adhesion findings showed that MG-63 cells adhered and spread well on the Ak disc, suggesting that Ak discs possess good biocompatibility. The results of the MTT assay demonstrated that the cell proliferation of osteoblast-like MG-63 cells was enhanced with the increase in culture time. Our in vitro bioactivity, cell morphology, and adhesion evaluations and in vitro biocompatibility assessment suggested that Ak powders were bioactive and cytocompatible and have a great potential to be selected as an ideal candidate for bone tissue engineering applications. [ABSTRACT FROM AUTHOR]

The purpose of this paper was to evaluate the feasibility of MXenes (Ti3C2Tx) enforcing corrosion resistance performance and thermal stability of waterborne polyurethane (WPU). Firstly, the Ti3C2Tx was modified by hydrolysis of titanium butoxide (TBOT) and the 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane. Then, the modified Ti3C2Tx (SiOx/TiO2@Ti3C2) was grafted into the WPU composite. The electrochemistry station and thermal analysis technique was used to detailly evaluate the effect of SiOx/TiO2@Ti3C2 on the anticorrosion performance and thermal stability of all samples. The results revealed that the WPU with 0.15% SiOx/TiO2@Ti3C2 showed the best thermal stability and anticorrosion performance. In detail, 0.15% SiOx/TiO2@Ti3C2/WPU improved the 31.71 °C Tmax1 compared with that of WPU. In terms of electrochemistry results, after 28 days of immersion in 3.5 wt.% NaCl solution, the |Z|f=0.01 Hz of WPU was 3.65 × 106 Ω·cm2. However, the |Z|f=0.01 Hz of 0.15% SiOx/TiO2@Ti3C2/WPU was still at 1.15 × 107 Ω·cm2, after 64 days of immersion in 3.5 wt.% NaCl solution. In a word, this work opened up a novel strategy to enhance the performances of WPU polymer via introducing the SiOx/TiO2@Ti3C2. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA)-based products can be found in a wide range of industrial applications due to their favorable performances. Unfortunately, neat PLA also exhibits some limitations which could be overcome by blending, composites or self-reinforced compounding. On the other hand, the mechanical characterization of PLA during in vitro degradation process has been generally limited to some basic mechanical tests which can be improved by the application of fracture mechanics analysis. The PLA matrix was reinforced (2.5 to 20 wt.%) with hydroxyapatite (HA) and processed as film or fiber in order to be experimentally evaluated. The evolution of mechanical performance during in vitro degradation was characterized by stress-based analysis and fracture mechanics. The composites displayed similar particle size distributions and more frequent agglomeration at large filler content. The film with 2.5% HA showed an enhanced crack resistance followed by a drastic drop at shorter immersion times linked to a premature matrix degradation. Fibers displayed higher tensile performance, compared to films, and faster degradation in accordance with thinner cross section. The performed characterizations indicated hydrolysis of PLA controlled by autocatalytic random scission and marginal end scission. Experimental behavior also showed an energy–stress transition, with the filler volume fraction, to define the most sensitive mechanical parameter. The whole performance during in vitro degradation can be described by three stages: (i) running-in, (ii) steady and (iii) severe. Particularly, the combination of composition, compounding method and evaluated mechanical parameter defines the presence or not of these three different stages along the in vitro degradation process. [ABSTRACT FROM AUTHOR]

The slow approach to equilibrium concentration indicative of non-Fickian diffusion in polymer composites necessitates experimental time frames which are often of limited feasibility. As a result, experimental studies are terminated prematurely due to time constraints or incorrect identification of equilibrium. Here, the three-dimensional anisotropic diffusion behaviors of six-, twelve-, and forty-ply quartz-reinforced bismaleimide laminates are quantified through a 5-year, full-immersion gravimetric absorption study. The applicability of the three-dimensional hindered diffusion model is investigated, while projections of future absorption behavior made at 21 months are revisited in light of 3 years of additional data. The mathematical equivalency of the hindered diffusion model and a diffusion-relaxation model under certain conditions is discussed. Moisture content rises continuously throughout the 5-year experiment for all samples. In the six-ply case, the standard termination criterion for the equilibrium condition is met before 6 months and 1.38 % moisture content by weight. Actual moisture content reaches 1.56 % after 5 years. The hindered diffusion model and associated forward projections of moisture content are found to conform well to experimental results. [ABSTRACT FROM AUTHOR]

Methanol crosslinking and heat-treatment methods for physical crosslinking of electrospun poly(vinyl alcohol) (PVA) nanofibres were investigated to assess their stability in water. For this purpose, PVAs with low and high molecular weights were selected. Morphology of the crosslinked membranes was characterised by scanning electron microscopy. Crystallinity of the resultant crosslinked fibres were analysed by FT-IR and differential scanning calorimetry. It has been shown that physical crosslinking increases the crystallinity of the fibres. High molecular weight PVA nanofibres showed better stability and better preservation of nanofibrous structure. Stability of the crosslinked membranes was also tested by immersion into water at room temperature and boiling water. Combined methanol and heat treatments at different temperatures and exposure periods were also investigated. Treatment at 180 °C HMW PVA nanofibres for longer durations exhibited best results in terms of water stability, although it exhibited somewhat lower swelling ratios as compared to those subjected to only methanol treatment. [ABSTRACT FROM AUTHOR]

A novel nanocontainer using graphene oxide nanoscrolls (GONS) as shell and benzotriazole (BTA) as core is proposed and embedded in epoxy coating for the corrosion protection of carbon steel. BTA/GONS nanocontainer is effectively fabricated by a modified shock-cooling approach. The hybrid material takes the specific shape of graphene oxide sheet spirally wrapped into scroll structure, acting as favorable physical barrier to afford encapsulation performance. A high uptake and storage of BTA in GONS is achieved, showing a loading capacity of 78.40%. The fantastically scrolled structure also provides an effective network to well control the BTA liberation during long-term immersion. The transport of BTA is diverse with pH values. The maximum release capacity of BTA occurs in neutral condition, larger than that in acid or alkaline environment. The liberation for up to 456 h exhibits the steady releasing characteristics of the containers. The corrosion inhibition performance of BTA/GNOS containers was mainly evaluated by electrochemical impedance spectroscopy. In comparison with, the reference epoxy coating, the one modified by BTA/GNOS nanocontainers demonstrate more excellent anticorrosion ability. The successful embedding and homogeneous distribution of BTA-loaded GNOS nanocontainers in epoxy film contributes to the improvement in the corrosion resistance of Q235 carbon steel and the self-healing performance of the coating. [ABSTRACT FROM AUTHOR]

This work creatively utilized the pH-dependent electrostatic interactions between L-valine (L-Val) and halloysite nanotubes (HNTs) to fabricate pH-responsive anticorrosion materials and compared with 2-mercaptobenzothiazole (MBT)-loaded HNTs, which were assembled via layer-by-layer (LbL) selfassembly. These two methods can achieve controlled release of inhibitors and self-healing performance. However, the loading capacity of L-Val-loaded HNTs is higher than that of MBT’s. There are 12 and 7 wt%, respectively. The pHresponsive release property was systematically evaluated by ultraviolet–visible (UV/Vis) spectrophotometry measurement. It demonstrates that 98% of adsorbed L-Val molecules released from HNTs within 300 min at pH 10 while the loaded MBT needs 120 h to achieve the equal ratio. Moreover, the difference of the release rate has a significant impact on the artificial crossed scratch experiment and shows a great performance gap in photographs. By comparing electrochemical impedance spectroscopy (EIS) data of three epoxy coatings, it can be seen that the epoxy coating, which was mixed with L-Val-loaded HNTs, shows a better anticorrosion ability than the epoxy coating contains MBT-loaded HNTs after immersion in 3.5 wt% sodium chloride solution for 96 h. Crucially, the pH-responsive anticorrosion material we fabricated can offer a rapid selfhealing performance when the coating damaged by mechanical scratch via visual test and atomic absorption spectroscopy. [ABSTRACT FROM AUTHOR]

A novel micro-zone electrochemical exfoliation method for the large-scale fabrication of nitrogen-doped carbon quantum dots (N–CQDs) from pre-baked carbon anode (PCA) in ammonium bicarbonate electrolyte has been demonstrated. Therefore, an efficient (90.18 wt% utilization rate of raw material and high-yield conversion of 1.87 g(N-GQDs)g(PCA)−1 due to oxidation weight gain) and environment-friendly mass production (9.36 g in one pot) for N–CQDs really becomes promising and practical. Moreover, the N-CQDs with abundant functional groups and higher nitrogen content (30.18 at%) present strong dispersion stability and enhanced interfacial adsorption with copper substrates. By virtue of the excellent performance, we successfully applied the N–CQDs as an effective inhibitor to alleviate the corrosion of copper. Results showed the corrosion inhibition efficiency of the self-assembled N–CQDs film on the copper reached up to 96.32% at 150 mg/L N–CQDs. The mechanism for the realization of large-scale preparation and self-assembly of N–CQDs was also proposed. [ABSTRACT FROM AUTHOR]

Melt-spun Mg-1 and 15 wt % Pr binary alloys were immersed in a 3% NaCl solution saturated with Mg(OH)2 for up to 72 h. The dissolution rate was evaluated by hydrogen evolution method. Surface characterization of the pristine and corroded surfaces has been carried out using X-ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The surfaces of both the pristine and corroded samples were found to consist mainly of Mg(OH)2 and MgO. However, results of XRD and SEM showed that the dominant product formed on the corroded sample was Mg(OH)2. SIMS depth profiling showed that there was a depletion of Pr at the surfaces of Mg–Pr samples. © 1998 Chapman & Hall [ABSTRACT FROM AUTHOR]

In this work, comparative studies of the corrosion behavior of titanium manufactured by powder metallurgy (porous) and traditional technology (wrought) in aqueous solutions of hydrochloric and sulfuric acids of various concentrations were performed. Electrochemical, static immersion tests, and microstructural characterization pursued an influence of acid concentration on corrosion resistance and corrosion behavior. As expected, porous titanium had worse electrochemical performance and corrosion rate than non-porous wrought titanium in the studied acids; the presence of pores in titanium accounts for this. According to SEM and EDX analysis of corroded titanium surfaces, the corrosion mechanisms and their main differences for porous and non-porous wrought titanium were established. The safe use of porous titanium in sulfuric acid in the concentration range above 40% and up to 60% was confirmed. It was determined that the use of porous titanium in hydrochloric acid be limited due to its tendency to pitting. To improve the anticorrosion properties of porous titanium in hydrochloric acid, it is recommended to reduce the negative effect of pores, for example, by surface modification. This work demonstrates the range of acid concentrations beneficial for the operation of porous titanium. It provides referenceable data for designing and manufacturing products in the chemical, metallurgical, and other branches of industry. [ABSTRACT FROM AUTHOR]

The reboiler tube bundle is prone to stress corrosion cracking in high temperature, high chlorine and oxygen environment. The composite film of graphene oxide (GO)/dodecyl triethoxysilane (DTES) was successfully prepared on the surface of 2205DSS by electrodeposition. The DTES/GO composite film's polarization resistance value increased 96 times. The DTES/GO composite film layer acts as a physical barrier, extending the path of corrosive species diffusing to the substrate interface and preventing corrosive ions from reaching the substrate, effectively slowing down the stress corrosion cracking process and significantly improving the 2205DSS resistance to stress corrosion cracking. [ABSTRACT FROM AUTHOR]

The movement of water molecules at the atomic scale within the calcium silicate hydrate (C–S–H) gel pores serves a dual role: it creates an environment for harmful chemical reactions within the pores and functions as a carrier for the transport of detrimental ions, thereby affects the mechanical properties and durability of cementitious materials. However, direct experimental observation poses substantial challenges. This study offers new insights into how temperature (253 K, 273 K, 293 K, and 313 K) affects the capillary transport of water molecules in epoxy-modified C–S–H. The findings demonstrate that the pore size undergoes continuous changes during immersion due to epoxy clustering or detachment, resulting in three scenarios: narrowing of epoxy/C–S–H channels (253 K, 273 K), channel blockage (293 K), and complete detachment (313 K). Moreover, the interactions between water molecules and epoxy lead to epoxy detachment or cluster formation on the C–S–H surface. As the temperature increases, the interaction between C–S–H and cross-linked epoxy resin weakens. The coordination between C–S–H and epoxy resin decreases, while the coordination with water increases. This paper provides valuable insights into the transport behavior of liquids within the epoxy-modified C–S–H pores of cement-based materials. It contributes to a better understanding of how liquids move and interact within the modified pore structure, which is beneficial for enhancing the performance and properties of cement-based materials. [ABSTRACT FROM AUTHOR]

Considered the fact that the study on how nitrogen influences the general corrosion behavior of high-strength low-alloy steel, we explored the effect of nitrogen on the corrosion of low-alloy high-strength steel in a simulated marine atmosphere from the aspects of corrosion rate analysis, corrosion products analysis, morphology analysis, and electrochemical analysis. Several experimental methods include electron backscattered diffraction, transmission electron microscopy, and inductively coupled plasma mass spectrometry were adopted. The findings reveal that the addition of nitrogen increases the yield strength by about 20 MPa and the tensile strength by about 40 MPa. The addition of 0.02 wt.% N to steel does not significantly improve the average corrosion resistance but slightly decreases the ratio of the maximum corrosion depth to the average corrosion depth. Nitrogen is present as ammonium ions and is enriched at the bottom of corrosion products. Overall, the alloying of 0.02 wt.% N slightly enhances the polarization resistance and increases the stability of corrosion products, whereas it has no obvious improvement on decreasing the corrosion rate. [ABSTRACT FROM AUTHOR]