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TiO2 nanotubes (TNT) formation is beneficial for improving bone cell–material interaction and drug delivery for Ti dental implants. Among the natural drugs to be installed in TNT, selected propolis has antibacterial and anti-inflammatory properties. It is a resinous natural product which is collected by the honeybees from the various types of plants with their salivary enzymes. This study concludes that TNT loaded with a propolis (PL-TNT-Ti) dental implant has the ability to improve osseointegration. The propolis particles were embedded within the TNT or adhered to the top. In a cytotoxicity test using osteoblast, PL-TNT-Ti group exhibited an increased cell proliferation and differentiation. A Sprague Dawley rat mandibular model was used to evaluate the osseointegration and bone bonding of TNT or PL-TNT-Ti. From the µ-CT and hematoxylin and eosin (HE) histological results after implantation at 1 and 4 weeks to rat mandibular, an increase in the extent of new bone formation and mineral density around the PL-TNT-Ti implant was confirmed. The Masson’s trichrome staining showed the expression of well-formed collagenous for bone formation on the PL-TNT-Ti. Immunohistochemistry staining indicate that bone morphogenetic proteins (BMP-2 and BMP-7) around the PL-TNT-Ti increased the expression of collagen fibers and of osteogenic differentiation whereas the expression of inflammatory cytokine such as interleukin-1 beta (IL-1s) and tumor necrosis factor-alpha (TNF-α) is decreased.

The performance of a new dry CO2 sorbent KEP-CO2P2 was tested for an extended period of time of 650 hours in a 0.5 MW e CO2 capture test bed at Hadong coal-fired power plant. The mass-produced CO2 dry sorbent, KEP-CO2P2 was tested for CO2 sorption and regeneration capacity. With modification of the process as well as the use of KEP-CO2P2 sorbent in a 0.5 MW e CO2 capture test bed, 85% (81–90%) CO2 removal rate was achieved in continuous operation of 650 hours. Samples were collected and analyzed using particle size analyzer (PSA), ion chromatograph (IC), inductively coupled plasma (ICP), field emission-scanning electron Microscope (FE-SEM), electron probe X-ray micro-analyzer (EPMA) and X-ray diffractometer (XRD). The analysis showed that KEP-CO2P2 was not affected by SO x , and there were no side reactions to consume K2CO3. However, the regeneration of the sorbent was not complete to need future investigation.

We report a facile method for preparing hybrid nanostructured films composed of poly(3-hexlythiophene) (P3HT) and [6,6]-phenylC61-butyric acid methyl ester (PCBM) with silver (Ag) nanorods (AgNRs) array. The AgNRs were synthesized by an electrochemical deposition method using an anodic aluminum oxide template with 50-nm-pore-diameter and 10-μm-thickness. The nanostructured P3HT/PCBM film was formed by the intercalation of AgNRs into the P3HT/PCBM film. The nanostructured P3HT/PCBM film with AgNRs showed enhanced optical absorption in the spectral range of 300–650 nm due to localized surface plasmon resonance and scattering effects around the AgNRs compared with spin-coated and nanopatterned P3HT/PCBM films without AgNRs. © The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@electrochem.org. [DOI: 10.1149/2.0021504ssl] All rights reserved.

A highly efficient light-scattering layer, composed of quasi-periodic discrete silica nanoparticles directly deposited onto polymer substrates to produce bendable organic solar cells (OSCs) with enhanced light absorption, is reported. A silica nanoparticle layer (SNL) underwent self-assembly on a highly flexible and heat-sensitive polymer at room temperature during fabrication, which employed a unique plasma-enhanced chemical vapour deposition technique. Such efficient light-scattering SNLs have not been realizable by conventional solution-based coating techniques. SNLs were optimized by precisely controlling dimensional parameters, specifically, the nanoparticle layer thickness and interparticle distance. The optimized SNL exhibited an improved transmission haze of 16.8% in the spectral range of 350–700 nm, where reduction of the total transmission was suppressed to 2%. Coating light-scattering SNLs onto polymer substrates is a promising method for improving the light harvesting abilities of OSCs by enhancing the light absorption of photoactive polymer layers. This SNL-based flexible OSC exhibited a record power conversion efficiency (PCE) of 7.4%, representing a 13% improvement, while reducing the thickness of the photoactive polymer layer by 30%.

This study was performed to evaluate the effect of a lithium-disilicate spray-liner application on both the bond strength between zirconia cores and heat-pressed lithium-disilicate glass-ceramic veneers, and the fracture strength of all-ceramic zirconia crowns. A lithium-disilicate reinforced liner was applied on the surface of a zirconia core and lithium-disilicate glass-ceramic was veneered on zirconia through heat press forming. Microtensile and crown fracture tests were conducted in order to evaluate, respectively, the bonding strength between the zirconia cores and heat pressed lithium-disilicate glass-ceramic veneers, and the fracture strength of bilayered zirconia all-ceramic crowns. The role of lithium-disilicate spray-liner at the interface between zirconia and lithium-disilicate glass-ceramic veneers was investigated through surface and cross-sectional analyses. We confirmed that both the mean bonding strength between the zirconia ceramics and lithium-disilicate glass-ceramic veneers and the fracture strength of the liner-treated groups were significantly higher than those of the untreated groups, which resulted, on the one hand, from the chemical bonding at the interface of the zirconia and lithium-disilicate liner, and, on the other, from the existence of a microgap in the group not treated with liner.

TiO2 nanotubes (TNT) formation is beneficial for improving bone cell–material interaction and drug delivery for Ti dental implants. Among the natural drugs to be installed in TNT, selected propolis has antibacterial and anti-inflammatory properties. It is a resinous natural product which is collected by the honeybees from the various types of plants with their salivary enzymes. This study concludes that TNT loaded with a propolis (PL-TNT-Ti) dental implant has the ability to improve osseointegration. The propolis particles were embedded within the TNT or adhered to the top. In a cytotoxicity test using osteoblast, PL-TNT-Ti group exhibited an increased cell proliferation and differentiation. A Sprague Dawley rat mandibular model was used to evaluate the osseointegration and bone bonding of TNT or PL-TNT-Ti. From the µ-CT and hematoxylin and eosin (HE) histological results after implantation at 1 and 4 weeks to rat mandibular, an increase in the extent of new bone formation and mineral density around the PL-TNT-Ti implant was confirmed. The Masson’s trichrome staining showed the expression of well-formed collagenous for bone formation on the PL-TNT-Ti. Immunohistochemistry staining indicate that bone morphogenetic proteins (BMP-2 and BMP-7) around the PL-TNT-Ti increased the expression of collagen fibers and of osteogenic differentiation whereas the expression of inflammatory cytokine such as interleukin-1 beta (IL-1ß) and tumor necrosis factor-alpha (TNF-α) is decreased.

In this study, for improving the bioactivity of titanium used as an implant material, alkali and heat treatments were carried out after formation of the nanotubes via anodization. Nanotubes with uniform length, diameter, and thickness were formed by anodization. The alkali and heat-treated TiO2 nanotubes were covered with the complex network structure, and the Na compound was generated on the surface of the specimens. In addition, after 5 and 10 days of immersion in the SBF, the crystallized OCP and HAp phase was significantly increased on the surface of the alkali-treated TiO2 nanotubes (PNA) and alkali and heat-treated TiO2 nanotubes (PNAH) groups. Cell proliferation was decreased due to the formation of amorphous sodium titanate (Na2TiO3) layer on the surface of the PNA group. However, anatase and crystalline sodium titanate were formed on the surface of the PNAH group after heat treatment at 550 °C, and cell proliferation was improved. Thus, PNA group had higher HAp forming ability in the simulated body fluid. Additional heat treatment affected on enhancement of the bioactivity and the attachment of osteoblasts for PNA group.

In recent years, extensive research has been carried out on the potential of using magnesium for biodegradable implants. However, the fast rate of corrosion of magnesium remains one of the major limitations of using Mg and Mg alloys as implants. The present work aimed to deposit a corrosion-resistant coating onto pure Mg (≥ 99.93%) in a saturated ammonium hydrogen fluoride solution at 120–200 V by micro arc fluorination (MAF) to improve resistance to corrosion. The treated samples were then characterized by SEM, EDS and XRD to assess morphological, chemical and structural characteristics. Electrochemical corrosion and immersion tests were used to evaluate the level of corrosion resistance. To test the coatings in vitro, MC3T3-E1 cells were cultured on the surface and cell viability was analyzed. A layer of dense ceramic coating with micro pores was observed on the surface. The thickness of the coatings ranged from approximately 2.5 to 5.5 μm. XRD and EDS analyses indicated that the coatings formed on the magnesium surface were composed of MgF 2 . Electrochemical and immersion tests performed in the SBF proved that the anodic fluorination coatings significantly improved the corrosion resistance of pure Mg. In the in vitro assay, both the proliferation and adherence rates of cells grown on the MgF 2 coatings improved compared with the untreated group.

The bone‐bonding ability of a material is generally assessed by examining the apatite forming ability in simulated body fluid. The bone‐bonding ability can be increased by increasing the surface roughness and forming a surface similar to the bone. In this study, pretreatments of titanium used for dental implant were anodized at a high voltage to form micropores, and at a low voltage to form nanotubes. In addition, pack cementation was performed on the pretreated specimens in a crucible filled with TTCP (tetracalcium phosphate) powder at 700 °C for 24 h to impart bioactivity. After pack cementation, apatite formed on the surface of all specimens. In particular, the amount of apatite was higher in the anodized specimens. The specimen immersed in SBF for one day was shown to form apatite on the entire surface due to the effect of anodic oxidation pretreatment of forming nanotube, thereby exhibiting the highest bioactivity. The surface roughness was significantly high in the anodized specimens (P Overall, the pretreatment and pack cementation are expected to be used for the surface modification of implant materials.

The effect of polydopamine coated titanium such as surface roughness, wettability, cell growth and toxicity, and corrosion resistance. The polydopamine-coated titanium was successfully prepared from dopamine solution and bright polydopamine granules were randomly distributed on titanium surface after coating process. The surface roughness was not significantly decreased in the pure titanium (P>0.05), but significantly decreased (P

The present study addresses the deposition of a duplex coating by microarc oxidation (MAO) treatment and polycaprolactone (PCL) coating to improve the corrosion resistance of Mg. A uniform PCL coating layer is formed by dip coating method on MAO treated Mg, and the corrosion resistance of MAO–PCL duplex coated Mg is evaluated by potentiodynamic polarization study and immersion test. The results reveal that the porous nature of MAO treated Mg fails to offer a better corrosion resistance in Hanks' balanced salt solution (HBSS). However, deposition of PCL coating (using 4 and 7 wt.% PCL) over MAO treated Mg significantly increased the corrosion resistance of Mg in HBSS for 7 days. The MAO–PCL duplex coating can be a good alternative method of protecting Mg from rapid corrosion for biodegradable implant applications.

The sensitivity of a biosensor electrode was increased by introducing hydrophilic N-groups onto the surface of a polyacrylonitrile (PAN) based activated carbon fiber. The electrospun carbon fiber was activated using KOH to improve the adsorption of glucose oxidase (GOx) enzymes through pore production and the introduction of oxygen functional groups. The activated carbon fibers (ACFs) were then reacted with urea to increase their hydrophilicity by doping their nitrogen groups. The sensor sensitivity and the Michaelis-Menten constant, Km, were altered by varying the percentages of functional groups on the electrode surfaces. Whereas the value of Km was affected by the kind of functional groups, the sensitivity of the biosensor electrode was chiefly affected by the amount of functional groups introduced urea modification because the enzyme was better immobilized onto urea-modified activated carbon fibers. Quantitatively, the sensitivity was two- to three-fold higher for the biosensors based on urea-treated ACFs than those based on untreated ones. This increased sensitivity is attributed to the nitrogen and oxygen functional groups on the urea-modified ACFs.

This study investigated the effects of anodization-cyclic precalcification-heat (APH) treatment on the bonding ability of Ca-P coating to the parent metal and osseointegration of Ti-6Al-7Nb implants. Eighteen Ti-6Al-7Nb discs, 9 untreated and 9 APH-treated, were cultured with osteoblast cells in vitro, and the cellular differentiation ability was assayed at 1, 2, and 3 weeks. For in vivo testing, 28 Ti-6Al-7Nb implants (14 implants of each group) were inserted to rat tibias, and after each 4 and 6 weeks of implantation, bone bonding, and osseointegration were evaluated through removal torque and histological analysis. Osteoblast-culturing showed twice as much of the alkaline phosphatase activity on the treated surface at 3 weeks than on the untreated surface (p

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This study was conducted to test the hypothesis that heat-bonding with a liner positively affects the bond strength and fracture resistance of an implant-supported glass&ndash, ceramic crown bonded to a zirconia abutment produced by a computer-aided design/computer-aided milling (CAD/CAM) procedure. Lithium disilicate-reinforced Amber Mill-Q glass ceramic blocks were bonded to 3 mol% yttria stabilized tetragonal zirconia polycrystal (3Y-TZP) blocks by heat-bonding with a liner or cementation with a dual-cure self-adhesive resin cement for a microtensile bond strength test. CAD/CAM implant-supported glass ceramic crowns were produced using Amber Mill-Q blocks and bonded to a milled 3Y-TZP zirconia abutments by heat-bonding or cementation for a fracture test. A statistical analysis was conducted to investigate the significant differences between the experimental results. The mode of failure was analyzed using high-resolution field emission scanning electron microscopy. Chemical bonding was identified at the interface between the zirconia ceramic and liner. The mean tensile bond strength of the liner-bonded group was significantly higher than that of the cement-bonded group. The initial chipping strength of the liner-bonded group was significantly higher than that of the cement-bonded group, although no statistically significant difference was found for the fracture strength. The mode of failure was mixed with cohesive fracture through the liner, whereas the cement-bonded group demonstrated adhesive failure at the interface of bonding.

This study was performed to evaluate the effect of collagen-multi-walled carbon nanotubes (MWCNTs) composite coating deposited on titanium on osteoblast growth. Titanium samples coated with only collagen and MWCNTs were used as controls. Pure titanium was coated with collagen-MWCNTs composite coating with 5, 10 and 20 μg cm−2 MWCNTs by dip coating method. Scanning probe microscopy, field emission scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy were used to ascertain the root mean squared roughness, structural and morphological features and, the interaction between the collagen and the MWCNTs, respectively. The biocompatibility of the collagen-MWCNTs composite coated Ti was assessed by MTT and ALP activity assays after culturing the cells for 2 and 5 days. The study reveals that root mean squared surface roughness of collagen-MWCNTs composite coated titanium is relatively higher than those of collagen and MWCNTs coated Ti. There is a strong interaction between the MWCNTs and the collagen, which is supported by the inferences made in FE-SEM and TEM studies and further confirmed by FT-IR spectra. Among all the specimens tested, cell proliferation is relatively higher on collagen-MWCNTs composite coated Ti specimen incorporated with 20 μg cm−2 of MWCNTs (p

We report a simple protocol for the fabrication of multiwalled carbon nanotubes (MWCNTs) with a neuron-like structure for loading ultra-high densities of metal nanoparticles (NPs). The MWCNTs were initially coated with an anionic polyelectrolyte (PE), polystyrene sodium sulfonate (PSS), using a noncovalent interaction (CNT/PSS). The neuron-like structures were fabricated through the stepwise assembly of both the positively charged poly(allylamine) hydrochloride (PAH) and negatively charged poly(acrylic acid) (PAA) in a nonstoichiometric ratio on the CNT/PSS as a template. After three coatings with the PEs, the obtained neuron-shaped CNTs were used as a support for loading a high density of multi-metallic NPs. Moreover, a unique characteristic, tunable and side specific growth of the metal NPs, was also observed. Our neuron-like structures with high loadings of multi-metallic NPs were demonstrated to be catalytic materials for the conversion of 4-nitrophenol to 4-aminophenol and as convenient surface-enhanced Raman scattering substrates for biological tags and molecular detection.

This work describes the effect of electrolyte agitation conditions on the anodic growth of nano-structured titanium oxide on titanium samples of size 20 mm × 10 mm (thickness 2 mm) in an electrolyte containing 0.02 M calcium glycerophosphate (Ca-GP) and 0.15 M calcium acetate (CA). Magnetic stirring and different intensities of ultrasonic waves were applied during anodization. The application of ultrasonic waves during anodization was found to increase the reaction rates; the higher the ultrasonic irradiation power, the faster the growth rate of nano-structured titania. The diameters of the pores created under ultrasonic wave conditions were found to be larger than those of the pores created under magnetic stirring conditions in the corresponding nano-structured titania. An increase in the sonication power to 180, 250, and 350 W resulted in an increase in the density, uniformity and diameters of the pores, respectively. The surface roughness and Ca/P ratio also increased with an increase in the sonication power. It was found that the applied ultrasonic wave could determine the surface morphology, properties and compositions of the anodic oxide films. We believe that sonoelectrochemistry is a simple method to design and synthesize nanostructured titanium oxide for implant applications.

This study examined the growth behavior of anodic TiO 2 nanotubular layer in glycerol solutions and the bioactivity of a TiO 2 nanotubular layer that was modified by precalcification treatment. A glycerol solution containing 1 wt.% NH 4 F and 20 wt.% deionized water was used as the electrolyte. Anodization was carried out at 20 V at a current density of 20 mA/cm 2 for 1 h. The anodized specimens were precalcified by soaking in a Na 2 HPO 4 solution at 80 °C for 30 min followed by soaking in a saturated Ca(OH) 2 solution at 100 °C for 30 min and heat-treatment at 500 °C for 2 h. To evaluate the bioactivity of the precalcified TiO 2 nanotube layer, hydroxyapatite precipitation was examined in simulated body fluid at pH 7.4 and 36.5 °C for 10 days. During the electrochemical oxidation process, a thin strip-like net structure was formed at the initial stage, which then developed into a well-arranged and self-organized nanotubular TiO 2 layer. The nanotubular TiO 2 layer had a dense structure due to the interpositioning of small diameter nanotubes between the larger diameter nanotubes, and the diameter of the nanotubes increased in the direction towards the substrate. The diameter of the TiO 2 nanotubes increased with increasing applied potential and water content in the glycerol electrolyte solution. The diameters of the nanotubes grown on the samples treated in a glycerol solution containing 20 wt.% H 2 O and 1 wt.% NH 4 F at 20 V were 122.9 ± 15.2 nm and 88.5 ± 9.5 nm, and the length of nanotubes was 567.0 ± 27.2 nm. The bioactivity of the Ti–6Al–4V alloy implant was improved with the formation of a nanotubular TiO 2 layer and precalcification treatment in a 0.5 M Na 2 HPO 4 and saturated Ca(OH) 2 solution.

Hollow core mesoporous shell carbon (HCMSC) capsules are prepared by nano-casting method which involves surfactant-assisted synthesis of silica spheres with mesoporous shell as template and impregnation of carbon precursor into mesoporous shell of the silica, followed by carbonization and silica template removal. The resulting HCMSC capsules possess 3D-interconnected nanoarchitecture with unique hierarchical meso/macro-porosity along with high surface area and large mesopore volume. The HCMSC capsules are tested for electrochemical double layer capacitor in a standard two electrode flat cell using non-aqueous electrolyte. The specific capacitance measured by galvanostatic charge-discharge at 0.3 A g−1 current density is found to be 162 F g-1, which is among the highest values reported so far for mesoporous carbon materials in a practical two electrode symmetric system using organic electrolyte. The cyclic performance tested at high current density of 1.0 A g−1 is found to retain 88% of initial capacity up to 2000 charge-discharge cycles. High capacitance performance of the HCMSC is attributed to the well-developed hierarchical 3D open network of macropores and interstitial void open to mesopores in the mesoporous shell, which not only facilitate fast charge transfer, but also facile electrolyte movement to access the active sites.

We present a first time report on novel and easy low temperature hydrothermal method using glycine to synthesize α-Fe2O3 nanoparticles (NPs) and Vulcan carbon (VC)-supported α-Fe2O3 composite. Formation of complex between glycine and iron metal ions retards iron oxide nucleation process at early stage of reaction, resulting in uniform dispersion of the iron oxide with smaller particle size. The small α-Fe2O3 NPs are highly dispersed on the VC to form an iron oxide-carbon composite, which exhibits a high specific capacity of 1200 mAh g−1 as an anode material for lithium battery, significantly improving anode performance. The excellent performance observed with the α-Fe2O3/VC composite is ascribed to well-dispersed small iron oxide particles regulated by the novel glycine-assisted approach and the presence of a carbon support. In particular, remarkably, the activity of the α-Fe2O3/VC composite is much higher than combined sum of respective values of the bare α-Fe2O3 NPs and supporting VC, indicating strong favorable synergistic interaction between α-Fe2O3 and VC in the composite. Our studies demonstrate that the carbon support plays remarkably important roles as a conductive buffer and as active sites for lithium storage in significantly improving Li ion storage capacity, cycle life and rate capability of the anode electrode.

An effective method for depositing highly transparent and conductive ultrathin silver (Ag) electrodes using minimal oxidation is reported. The minimal oxidation of Ag layers signifi cantly improves the intrinsic optical and structural properties of Ag without any degradation of its electrical conductivity. Oxygen-doped Ag (AgO x ) layers of thicknesses as low as 6 nm exhibit completely 2D and continuous morphologies on ZnO fi lms, smaller optical refl ections and absorbances, and smaller sheet resistances compared with those of discontinuous and granular-type Ag layers of the same thickness. A ZnO/AgO x /ZnO (ZAOZ) electrode using an AgO x (O/Ag = 3.4 at%) layer deposited on polyethylene terephthalate substrates at room temperature shows an average transmittance of 91%, with a maximum transmittance of 95%, over spectral range 4001000 nm and a sheet resistance of 20 Ω sq 1 . The average transmittance value is increased by about 18% on replacing a conventional ZnO/Ag/ZnO (ZAZ) electrode with the ZAOZ electrode. The ZAOZ electrode is a promising bottom transparent conducting electrode for highly fl exible inverted organic solar cells (IOSCs), and it achieves a power conversion effi ciency (PCE) of 6.34%, whereas an IOSC using the ZAZ electrode exhibits a much lower PCE of 5.65%.

Our study proposes a novel strategy for the synthesis of Ag derivatives (AgX@Ag (X = Cl and Br) or Ag nano/microtubes) using the controlled chemical reduction or electron-beam irradiation of AgX nanowires (NWs), which are formed from the controlled dewetting of a AgX thin film on colloidal particles. The size of the AgX@Ag and Ag nano/microtubes can be controlled using the AgCl NWs as templates and varying the concentration of NaX. By controlling the concentration of NaBr, heterojunction-structured AgCl/AgBr NWs (H-AgCl/AgBr NWs) can be produced from the AgCl NWs due to a partial ion-exchange reaction (low concentration), and the AgBr NWs produced after a complete ion-exchange reaction between Cl- and Br- are further grown into micrometer-sized AgBr wires (high concentration). The resulting AgX NWs can be transformed into corresponding AgX@Ag or Ag nano/microtubes via a controlled chemical or physical method. The AgX derivatives (AgX@Ag nanotubes (NTs) and AgX NWs) are tested as visible-light-induced photocatalysts for decomposition of methyl orange. The AgX@Ag NTs exhibit the best photocatalytic activities due to the advantages of the core@shell structure, allowing multiple reflections of visible light within the interior cavity, providing a well-defined and clean Ag/AgX interface, and preventing direct adsorption of pollutants on AgX because of the shell structure. These advantages allow AgX@Ag NTs to maintain high catalytic performance even after multiple uses. The approach can also be used as a direct method for preparing Ag nano/microtubes with a tailored size and as a new method for incorporating a AgX NW core into a Ag nano/microtube shell. Our approach is useful for synthesizing various types of one-dimensional heterostructured NWs or metal NTs with controlled structures and properties.

Magnesium and its alloys have been suggested as potential absorbable implant materials due to their excellent biodegradability and biocompatibility. Current researchers focus on reducing the rapid corrosion rate of Mg and its alloys by alloying and surface modification. To improve the corrosion resistance, pure Mg is modified by micro-arc oxidation (MAO) in phosphate electrolyte containing sodium hydroxide and its properties are compared with those formed using only phosphate or sodium hydroxide as electrolytes. A uniform and stable coating layer is formed on Mg after MAO treatment in phosphate electrolyte containing sodium hydroxide. The corrosion resistance of MAO-coated Mg is evaluated by potentiodynamic polarization study and immersion test. The results reveal that MAO coating enables a good improvement in corrosion resistance, and among them, coatings treated using phosphate electrolyte containing sodium hydroxide offer the best performance. Copyright © 2013 John Wiley & Sons, Ltd.

This study examined the fracture strength of 3-unit all-ceramic zirconia bridges treated with a melt-infiltration process of borosilicate glass. The zirconia specimens were milled with presintered yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) blocks. Before veneering the porcelain, borosilicate glass was infiltrated into the zirconia at 1,100°C for 1 hr. A 3-point flexural test was carried out at crosshead speed of 0.1 mm/min. The fracture surface and interface between the zirconia and veneer porcelain were observed by scanning electron microscopy. The fracture strength of the Y-TZP specimens was increased significantly by the melt-infiltration process of borosilicate glass (P < 0.05). The bond strength of the porcelain on zirconia was also improved significantly by meltinfiltration process of borosilicate glass (P < 0.05). The resistance to the initial chipping of the veneered porcelain in the 3-unit allceramic zirconia bridges was increased significantly by melt-infiltration process of borosilicate glass (P < 0.05). According to the microscopic observations of the fracture surface of porcelain, the glass-infiltrated zirconia group showed a rough fracture surface, whereas the sintered zirconia group showed a smooth fracture surface containing many pores.

A mini implant system made from Ti-6Al-4V alloy was used as the experimental material. The pull-out strength between the implant fixture and abutment was evaluated after the implant fixture and tapered abutment had been fixed by static compression loading, and hit with a mallet. Moreover, the fatigue limit was evaluated based on ISO/FDIS 14801:2003(E). In cases with compressive loading of 10, 50, 100, 150 and 200 N, the measured full-out load was 17.1 N, 33.6 N, 86.9 N, 99.7 N and 157.6 N, respectively. The full-out load measurements were 139.1 N and 195.6 N in the case of the mallet weight of 70 and 130 g, respectively (P < 0.05). The measured pull-out strength increased with increasing weight and number of mallet strokes, and the compression load. The compressive strength was examined according to the implant angle. The compressive strength in the 30° group was 532.2 ± 56.7 N, which was the highest value. On the other hand, the compressive strength in the 60° and 90° group was 156.7 ± 12.6 N and 117.3 ± 6.0 N, respectively. The fatigue life increased with decreasing applied strength level and the fatigue limit was 240 N.

Rod-shaped ordered mesoporous carbons (OMCs) with different lengths, prepared by replication method using the corresponding size-tunable SBA-15 silicas with the same rodlike morphology as templates, are explored as anode material for Li-ion battery. All of the as-synthesized OMCs exhibit much higher Li storage capacity and better cyclability along with comparable rate capability as compared with commercial graphite. Particularly, the OMC-3 with the shortest length demonstrates the highest reversible discharge capacity of 1012 mAh g(-1) at 100 mA g(-1) and better cyclability with 86.6% retention of initial capacity after 100 cycles. Although the Coulombic efficiencies of all the OMCs are relatively low at the beginning, they improve promptly and after 10 cycles reach the level comparable to commercial graphite. Based on their specific capacity, cycle efficiency, and rate capability, the OMC-3 outperforms considerably its carbon peers, OMC-1 and OMC-2 with longer length. This behavior is mainly attributed to higher specific surface area, which provides more active sites for Li adsorption and storage along with the larger mesopore volume and shorter mesopore channels, which facilitate fast Li ion diffusion and electrolyte transport. The enhancement in reversible Li storage performance with decrease in the channel length is also supported by low solid electrolyte interphase resistance, contact resistance, and Warburg impedance in electrochemical impedance spectroscopy.

We report a morphotropic phase transformation in vanadium dioxide (VO2) nanobeams annealed in a high-pressure hydrogen gas, which leads to the stabilization of metallic phases. Structural analyses show that the annealed VO2 nanobeams are hexagonal-close-packed structures with roughened surfaces at room temperature, unlike as-grown VO2 nanobeams with the monoclinic structure and with clean surfaces. Quantitative chemical examination reveals that the hydrogen significantly reduces oxygen in the nanobeams with characteristic nonlinear reduction kinetics which depend on the annealing time. Surprisingly, the work function and the electrical resistance of the reduced nanobeams follow a similar trend to the compositional variation due mainly to the oxygen-deficiency-related defects formed at the roughened surfaces. The electronic transport characteristics indicate that the reduced nanobeams are metallic over a large range of temperatures (room temperature to 383 K). Our results demonstrate the interplay between oxygen deficiency and structural/electronic phase transitions, with implications for engineering electronic properties in vanadium oxide systems.

As the proportion of adult orthodontic treatment increases, mainly for aesthetic reasons, orthodontic brackets are directly attached to yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) restorations. This, study analyzed the shear bond strength (SBS) between various surface treated Y-TZP and orthodontic metal brackets. The Y-TZP specimens were conditioned by 110 μm Al2O3 sandblasting, or sandblasting followed by coating with one of the primers (silane, MDP, or an MDP-containing silane primer). After surface treatment, the orthodontic metal bracket was bonded to the specimen using a resin cement, and then 24 h storage in water and thermal cycling (5000 cycles, 5–55 °C), SBS was measured. Surface roughness was analyzed for surface morphology, and X-ray photoelectron spectroscopy (XPS) was employed for characterization of the chemical bond between the Y-TZP and the MDP-based primers (MDP, MDP containing silane primer). It was found that after surface treatment, the surface roughness of all groups increased. The groups treated with 110 μm Al2O3 sandblasting and MDP, or MDP-containing silane primer showed the highest SBS values, at 11.92 ± 1.51 MPa and 13.36 ± 2.31 MPa, respectively. The SBS values significantly decreased in all the groups after thermal cycling. Results from XPS analysis demonstrated the presence of chemical bonds between Y-TZP and MDP. Thus, the application of MDP-based primers after Al2O3 sandblasting enhances the resin bond strength between Y-TZP and the orthodontic metal bracket. However, bonding durability of all the surface-treated groups decreased after thermal cycling.

In this study, a two-step surface treatment was developed to restrain the rapid primary degradation of a biodegradable Mg alloy and to improve their biocompatibility. Micro arc oxidation (MAO) coating was performed in alkaline electrolytes such as 1.0 M NaOH with 0.1 M glycerol and 0.1 M Na3PO4. Hydrothermal treatment was performed in 0.1 M Ca-EDTA (C10H12CaN2Na2O8) and 0.5 M NaOH solution at 90 °C for different times (6, 12, 24, and 48 h). The film morphology and chemical properties were evaluated by XRD and FE-SEM. The electrochemical and corrosion behaviors were examined in the simulated body fluid, and cytotoxicity was assessed using MC3T3-E1 cells. After MAO coating, an oxide layer containing $${\bf{P}}{{\bf{O}}}_{4}^{3-}$$ P O 4 3 − formed on the surface. During the hydrothermal treatment in Ca-EDTA solution, calcium phosphate and Mg(OH)2 were produced via a reaction between $${\bf{P}}{{\bf{O}}}_{4}^{3-}$$ P O 4 3 − on the surface and Ca2+ in solution. The layer with ceramics and oxides was grown on the surface with increasing hydrothermal treatment time, and improved the surface corrosion resistance. The 24 h hydrothermal-treated group showed the lowest immersion corrosion rate and high cell viability. Therefore, this treatment was the most favorable surface modification for improving the initial corrosion resistance and bioactivity of the biodegradable Mg alloy.

A glucose sensor electrode was prepared by thermally treating a pitch-based carbon material. Oxyfluorination was used to modify the surface of the prepared carbon to induce the formation of hydrophilic functional groups. A glucose oxidase enzyme was effectively loaded onto the surface of the oxyfluorinated carbon and was more sensitive in glucose sensing because of the effects of the improved interfacial affinity between the electrode and the glucose oxidase. The introduced hydrophilic functional groups were examined using XPS analysis. In current–voltage measurements, a higher current was observed in the samples prepared with a higher oxygen content. In addition, a clear redox peak was observed in the surface modified samples. These results can be attributed to efficient electrical resistance measurement by easy electron transfer during glucose sensing. An efficient glucose sensor electrode was prepared using pitch-based carbon, which has beneficial electrical properties, and oxyfluorination, which improves the surface interface.

We demonstrate the charge transport characteristics of MoS

We investigate strain-induced optical modulation in a ZnO microwire with wavy geometries induced by mechanical strains. Curved sections of the wavy ZnO microwire show red-/blue-shifts of near-band-edge emission and broadening of full width at half maximum in cathodoluminescence spectra along the length of the wavy ZnO microwire, compared with straight sections. The observed variations indicate that local strains in the wavy ZnO microwire lead to strain-dependent local changes of its energy band structure. The local bending curvature calculations using a geometric model also provide correlation between the shift of the near-band-edge emission peaks and the bending strain.

Purpose: The objectives of this study were to evaluate bioactivity of a titanium membrane with anodization, cyclic precalcification, and heat (APH) treatment (APHTM), and to compare APHTM and nontreated titanium membrane (NTTM) in guided bone regeneration using histologic analysis and microcomputed tomography (micro-CT). Materials and Methods: APHTM samples were prepared and immersed in simulated body fluid for 2 days, then observed using field-emission scanning electron microscopy, followed by an analysis of calcium and phosphate precipitation using an energy dispersive x-ray spectroscopy. For the in vivo experiment, critical-size defects were created in rat calvaria (diameter, 8 mm) and treated with either APHTM or NTTM (n = 14 each). Biopsies were performed at 2 and 4 weeks for histologic analysis (n = 3 per group each time). Fluorochrome bone markers were injected in three rats in each group at 3 (alizarin red) and 5 weeks (calcein green), followed by histologic examination at 7 weeks. Micro-CT was performed at 8 weeks (n = 5 per group). Results: APHTM exhibited high bioactivity, characterized by dense nano-sized flakelike crystals throughout the membrane and an increase in the calcium-phosphate concentrations after 2-day immersion in simulated body fluid. At 2 and 4 weeks, APHTM samples showed an intimate bone formation onto the membrane, whereas NTTM samples demonstrated interposition of connective tissue between the membrane and newly formed bone. The same pattern was found in the fluorescent study. The micro-CT analysis revealed significantly lower bone volume but higher bone mineral density in the APHTM samples than in the NTTM samples (P < .05). Conclusion: The results suggest that APH treatment on titanium membrane promotes intimate bone formation toward the membrane, thus increasing structural durability for bone regeneration. Further research is warranted to confirm the results found in these in vitro and in vivo experiments.

Nanostructure surface of titanium implants treated with anodic oxidation, heat, and bisphosphonates, has been introduced to improve osseointegration of the implants. However, no information could be found about the efficiency of these approaches on Ti-6Al-4V alloy surfaces. This study examined the drug loading capacity of anodized nanotubular Ti-6Al-4V alloy surfaces in vitro as well as the bone response to surface immobilized bisphosphonates (BPs) on anodized nanotubular Ti-6Al-4V alloy surface in tibiae of rats. Ti-6Al-4V alloy titanium was divided into two groups: (1) control group (nontreated); (2) test group (anodized, heat-, and bisphosphonate-treated group). In vitro, amount of the drug released from the both groups' specimens was examined; all samples were 1 × 2 cm in size. In vivo, the 10 implants were placed inside of tibias of five rats. After 4 weeks, the bone response of the implants was evaluated using a removal torque test, and measuring bone contact and bone area. In addition, the surfaces of the extracted implants were observed by FE-SEM and EDS. In vitro, the drug loading capacity of the Ti-6Al-4V alloy surfaces was enhanced by anodizing surface modification. The values of the removal torque, bone contact, and bone area were significantly higher in the test group (p < 0.05). Furthermore, according to the EDS analysis, the amounts of Ca and P on the surface of the extracted implants were higher in the test group. Within the limits of this experiment, results of this research demonstrated that bisphosphonate-treated Ti-6Al-4V alloy implants with nanotubular surfaces have positive effects in bone-to-implant contact.

The main starting valve that is operated by a pneumatic actuator is used to start a diesel engine. It is composed of a ball valve, a check valve, an actuator, etc. In this study, the existing design of a main starting valve is analyzed by the first axiom of axiomatic design theory. The first axiom is introduced to analyze and evaluate the design of a main starting valve. The design parameters (DPs) are determined sequentially by considering the Independence axiom. Then, for the structural design of a main starting valve, the strength is investigated through CFD and structural analyses. In addition, structural optimization of the actuator piston is performed to satisfy the imposed constraint. In this process, metamodels of the maximum stress and weight are built by the Kriging method of interpolation.

This study examined the in vitro cell-material interactions on four different types of titanium surfaces: a polished Ti surface, TiO 2 nanotube surfaces fabricated in a fluorinated glycerol solution (TN), fluorinated glycerol solution with 1 wt% anionic surfactant sodium dodecyl sulphate (TN-SDS), and fluorinated glycerol solution with 1 wt% cationic surfactant cetyl trimethyl ammonium bromide (TN-CTAB), respectively. The surfaces exhibited distinct surface morphologies and geometrical features. Surface energy calculation shows that TN surface enhances the hydrophilic character by significantly increasing the surface energy. The osteoblast cell growth behavior on the four different surfaces was examined using the MC3T3-E1 cell line for 1 day. When the anodized surfaces were compared for the cell-materials interaction, each of the surfaces showed different properties that affected the cell–material interactions. Proliferation of the cells was noticed with distinctive cell-to-cell attachment on the TN surfaces. Good cellular adhesion with extracellular matrix extensions between the cells was noticed in the TN samples. The TiO 2 nanotubes grown in the surfactant-assisted fluorinated electrolyte did not show significant cell growth on the surface and some cell death was observed. The cell adhesion, differentiation and alkaline phosphatase activity were more pronounced on the TN surface. The MTT assays also revealed an increase in living cell density and proliferation on the TN surfaces. Overall, a rough surface morphology and surface energy are important factors for better cell material interactions.

A glucose sensor electrode was prepared with multi-walled carbon nanotubes (MWNTs) because of its effect on surface modification through oxyfluorination. The oxyfluorination of MWNTs was carried out with F 2 :O 2 ratios of 7:3, 5:5 and 3:7, which are labeled F7O3-MWNT, F5O5-MWNT, and F3O7-MWNT, based on the oxyfluorination conditions. The hydrophilic functional groups were introduced effectively on the hydrophobic carbon surface. In addition, the amorphous area of the MWNTs was affected by oxyfluorination. The reactivity of the glucose sensor was affected by the oxyfluorination treatment and the existence of amorphous on MWNTs. The optimum O/F percentage was approximately 50%. Therefore, the oxyfluorination conditions are important with amorphous MWNTs. The sensitivity was improved based on the effects of improved interface affinity between the enzyme and the carbon electrode. In addition, the presence of an amorphous area on MWNTs seems to be beneficial for efficient glucose oxidase immobilization, which results in high-performance glucose sensing.

High-performance enzyme-based glucose sensors were prepared by electrospinning carbon fibers. The efficiency of the glucose sensor was assessed based on efficient enzyme immobilization and electrical resistance transfer by examining improved porosity and electrical properties, respectively. The porosity of the electrospun carbon fiber electrode was improved by physical activation to increase the immobilization sites of the glucose oxidase enzyme. The electrical properties were improved by a thermal treatment, which caused carbon orientation effects because of the high thermal energy. The glucose oxidase enzyme immobilization was developed based on improved specific surface area and pore volume, which were studied by pore structure and image analyzers. The glucose sensor was evaluated by amperometric measurements and cyclic voltammetry. The measured current increased with higher glucose concentrations based on the effects of the developed pore structure and the electrical properties. The enzymatic kinetics were also studied using the Lineweaver–Burk equation. The sensitivity of the glucose sensor was improved significantly with increased maximum current, whereas the GOD enzyme activity was diminished by efficient GOD immobilization. It is concluded that a high-performance glucose sensor was obtained using electrospun carbon fibers based on the effects of efficient GOD enzyme immobilization and electrical resistance transfer.

This study was conducted to investigate the biocompatibility of Mg-Zn-Ca ternary alloy as a biodegradable material. The casting alloy underwent anodization in an alkaline electrolyte at current density 300 mA/cm(2) and frequency 50 Hz to obtain porous oxide layer. Plasma anodization film using pulse was shown to form irregular porous oxide film. As a result of corrosion test, the corrosion current was shown to decrease and the corrosion voltage was shown to increase in the anodized group, which showed the improvement of corrosion resistance after surface treatment. Sodium silicate (0.1 M) was directly oxidized due to high charges caused by spark and then formed SiO(2), and the compounds produced inside the film were shown MgO, Mg(2) SiO(4), and SiO(2.) In the histological examination in rats, all samples of the untreated group were shown to be absorbed 3 weeks later into the body. After the magnesium alloy was implanted, blood vessel expansion and tissue change were shown in the adjacent tissues. However, the changed tissues were shown to return to normal muscle tissues 4 weeks later when the alloy was completely absorbed. These results suggest that anodized Mg-35Zn-3Ca alloy has good biocompatibility in vivo and controls the absorption rate of biomaterials.

Glucose-sensing electrodes were constructed from carbon fibers by electrospinning and heat treatment. By controlling the pore size, the specific surface area and pore volume of the electrospun carbon fibers were increased for efficient immobilization of the glucose oxidase. Carbon nanotubes were embedded as an electrically conductive additive to improve the electrical property of the porous carbon fibers. In addition, the surface of the porous carbon fibers was modified with hydrophilic functional groups by direct oxyfluorination to increase the affinity between the hydrophobic carbon surface and the hydrophilic glucose oxidase molecules. The porosity of the carbon fibers was improved significantly with approximately 28- and 35-fold increases in the specific surface area and pore volume, respectively. The number of chemical bonds between carbon and oxygen were increased with higher oxygen content during oxyfluorination based on the X-ray photoelectron spectroscopy results. Glucose sensing was carried out by current voltagram and amperometric methods. A high-performance glucose sensor was obtained with high sensitivity and rapid response time as a result of carbon nanotube addition, physical activation and surface modification. The mechanism of the highly sensitive prepared glucose sensor was modeled by an enzyme kinetics study using the Michaelis–Menten equation.

A glucose sensor electrode was prepared from electrospun spherical-type carbon materials. The glucose oxidase (GOD) enzyme was immobilized on a prepared electrode for efficient glucose sensing. The GOD immobilization was maximized by enlarged sites of carbon electrode and improved interfacial affinity between the carbon surface and the GOD achieved via physical activation and oxyfluorination, respectively. The specific surface area was enlarged significantly, by over 42 fold, through physical activation. In addition, the hydrophobic carbon surface was modified with hydrophilic functional groups by direct oxyfluorination for improved interfacial affinity between the carbon and GOD. Accordingly, the GOD immobilization improved significantly by approximately 9 fold. The glucose sensor was evaluated by amperometric measurements and cyclic voltammetry. The measured current increased with higher glucose concentrations based on the effects of the developed pore structure and the introduced hydrophilic functional groups. The enzymatic kinetics were also studied using the Lineweaver–Burk equation. The sensitivity of the glucose sensor was improved by approximately 3 fold with increased maximum current, whereas the GOD enzyme activity was diminished by efficient GOD immobilization. Conclusively, a high-performance glucose sensor was obtained using an electrospun spherical-type carbon material due to efficient GOD enzyme immobilization.

ZrO2-embedded carbon fibers were prepared for use as an electromagnetic interference (EMI) shielding material by electrospinning and heat treatment methods. Structural changes were observed in the ZrO2 and in the carbon structures by XRD and Raman spectroscopy, respectively. During heat treatment, XRD analysis results revealed a transition from a monoclinic structure to a tetragonal structure in ZrO2 and a graphitization in the structural formation of carbon fibers was observed by Raman spectroscopy. It was observed that these structural changes in the ZrO2 and the carbon fibers improved the real and imaginary permittivities by a factor of more than 3.5. The EMI shielding efficiency (SE) improved along with the permittivity with higher treatment temperatures and greater amounts of embedded ZrO2; the highest average EMI SE achieved was 31.79 dB in 800–8500 MHz. The heat treatment played an important role in the improvements in the permittivity and in the EMI SE because of the heat-induced structural changes of the ZrO2-embedded electrospun carbon fibers. We suggest that the EMI shielding of the fibers is primarily due to the absorption of electromagnetic waves, which prevents secondary EMI by reflection of electromagnetic waves.

A combination of carbon nanotubes (CNTs) and titanium (Ti) modified with TiO2 nanotubes (TiO2 NTs) was fulfilled with the aim of improving bioactivity of Ti implant. First, well-ordered TiO2 NTs were prepared by the electrochemical anodization of Ti in an ethylene glycol electrolyte containing 1 wt% NH4F and 10 wt% H2O at 20 V for 50 min, followed by annealing. Then, the carboxylated CNTs were coated onto the TiO2 NTs using electrophoretic deposition (EPD) technique. The growth of hydroxyapatite (HA) on the samples was investigated by soaking them in simulated body fluid (SBF). The result showed the CNTs-coated Ti with the modification of TiO2 NTs (CNTs-TiO2 NTs) was more efficient to induce HA formation than the CNTs-coated smooth Ti (CNTs-Ti). The vitro cell response was evaluated using osteoblast cells (MC3T3-E1). The good cell proliferation and strong cell adhesion could be obtained on the CNTs-TiO2 NTs. These results indicated that CNT coating on the Ti modified with TiO2 NTs could be potentially useful for the periodontal ligament combination on dental implants.

In situ composite coating of hydroxyapatite (HA)/TiO 2 were produced on titanium (Ti) substrate by micro-arc oxidation coupled with electrophoretic deposition (MAO&EPD) technique with different concentrations of HA particles in the 0.2 M NaOH electrolyte solution. The surface morphology and chemical composition of the hybrid coating were effected by HA concentration. The amount of HA particles incorporated into coating layer increased with increasing HA concentration used in the electrolyte solution. The corrosion behavior of the coating layer in simulated body fluids (SBF) was evaluated using a potentiodynamic polarization test. The corrosion resistance of the coated sample was increased compared to the untreated Ti sample. The in vitro bioactivity assessment showed that the MAO&EPD treated Ti substrate possessed higher apatite-forming ability than the untreated Ti. Moreover, the apatite-forming ability had a positive correlation with HA concentration. In addition, the cell behavior was also examined using cell proliferation assay and alkaline phosphatase ability. The coating formed at HA concentration of 5 g/L exhibited the highest cell ability.

The dispersing power of different surfactant-modified multiwalled carbon nanotubes (MWCNTs) and their effect on the antibacterial activity were examined. Three surfactants, including hexadecyltrimethylammonium bromide (CTAB), triton X-100 (TX-100) and sodium dodecyl sulfate (SDS) were tested. UV–vis absorbance, transmission electron microscopy and Fourier transform infrared spectroscopy were used to characterize the dispersion of MWCNTs in the aqueous phase, showing that the surfactant molecules had been adsorbed onto the MWCNTs’ surface. Among the three surfactants, TX-100 and CTAB provided maximum and minimum dispersion, respectively. The surfactant-modified MWCNTs exhibited different antibacterial activities to Streptococcus mutans. The fluorescence images showed that the surfactant-modified MWCNTs were not only capable of capturing bacteria and forming cell aggregates, but also killing them. Under the same concentration and treatment time, the CTAB-modified MWCNTs exhibited the strongest antibacterial activity compared to the TX-100 and SDS-modified MWCNTs. The optical density growth curves and viable cell number determined by the plating method suggested that the antibacterial activity of all surfactant-modified MWCNTs was both concentration- and treatment time-dependent.

To evaluate the effect of melt infiltration on the biaxial flexural strength of porcelain-bonded zirconia, borosilicate glasses were used in this study. Presintered yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) blocks were milled and used for disc specimens. Prior to veneering of porcelain, the infiltration of borosilicate glass on zirconia was performed at 1,100 °C for 1 h. After a biaxial flexural test with the crosshead speed of 0.1 mm/min, fractured surfaces and interfaces between zirconia and veneer porcelain were observed with a Scanning Electron Microscope (SEM). The fracture strength of sintered zirconia and veneer porcelain was significantly increased by the melt infiltration of borosilicate glass (P < 0.05). The melt infiltration process of borosilicate glass greatly improved the Weibull modulus of sintered zirconia. However, the Weibull modulus of porcelain increased slightly. The sintered zirconia group showed a smooth fracture surface containing many pores, but the glass-infiltrated zirconia group showed a rough fracture surface.

A polyacrylonitrile/carbon nanotube (CNT) complex was fabricated for use as a gas sensor using an electrospinning method. The surfaces of the multi-walled carbon nanotubes (MWCNTs) were modified by using a fluorination treatment to provide sufficient dispersion within the electrospun fibers. The electrospun fibers were thermally treated to obtain carbon fibers and then chemically activated to increase the number of active sites for efficient gas adsorption. The activation process improved the porous structure by increasing the specific surface area by approximately 115-fold. The gas-sensing ability and response time improved by introducing both the porous structure and the fluorinated MWCNTs. High-performance gas sensing followed a proposed mechanism, which included the effects of the activation and the MWCNT additive. The pore structure that developed as a result of activation significantly increased the amount of adsorbed gas and produced the high sensitivity of the gas sensor, while the MWCNTs led to a quick sensor response time due to the efficient transfer of resistance changes occurring on the surface of the fibers. Overall, due to the effects of chemical activation and fluorinated MWCNT additives, the sensor's sensitivity to NO gas improved by approximately 8 times, the response time decreased by approximately 60%.