Acid Anodizing Research Articles

The effects of pore widening and calcination on anodized aluminum oxide prepared from Al6082

In this study, semi-organized anodized aluminum oxide (AAO) is prepared by two-step anodization in oxalic acid using a low-purity aluminum (Al) alloy (Al6082) as the source material. Obtaining ideally ordered AAO layers from Al alloys is confounded by the presence of impurities and requires specialized post-anodization treatment. Here, a process is proposed for obtaining an AAO layer with a semi-ordered pore arrangement by means of calcination and pore-widening procedures. Calcination temperatures of 400–600 °C and pore–widening times of 15–120 min were explored. It was found that calcination improved the pore order of AAO layers from disordered to semi-ordered (defined as being near ideally ordered—one pore surrounded by six neighboring pores). In addition, it was found that calcination at 600 °C resulted in suitable pore widening of the AAO layer. The morphology of the AAO layers was characterized using scanning electron microscopy, which was applied to determine pore diameter, inter-pore distance, pore density, and AAO layer thickness. We found that calcinated and pore-widened AAO layers with pore diameters of 48.7 nm, inter-pore distances of 80.6 nm, and pore densities of 178 pores/μm2 could be prepared. The AAO preparation method proposed here is an economically attractive process suitable for the preparation of AAO layers due to the utilization of an inexpensive Al source.

Studies on the corrosion performance of an effective and novel sealing anodic oxide coating

The anodic oxide coating was formed on 2024-T3 aluminium alloy with sulfuric-boric acid anodizing. Then it was sealed with an alkaline Mn–Mo oxyanions electrolyte. This investigation revealed the surface morphology of the Mn–Mo sealed sample which showed flake-like surface cluster structure. EDS analysis results of the coating cross-section verified the relative even distribution of the oxygen, aluminium species, but Mo element existed in the outer region of the anodic coating. XPS analysis revealed the presence of hypervalent oxidation state soluble species of Mn and Mo such as MnOx, MnO2, MnO4−, MoO3/polymolybdate, MoOx and MoO2 and the hydration of Al2O3 and formation of pseudoboehmite during sealing process. The electrochemical characterization of the sealed anodic coatings with different baths was evaluated by electrochemical analysis techniques. The potentiodynamic polarization curves showed that the corrosion potential of the Mn–Mo sealed sample was the most positive. No corrosion pits were observed on the surface of Mn–Mo sample after salt spray test for 384 h. The formulated equivalent circuit is used to study the corrosion mechanism of the oxide film immersed in salt solution. The corrosion process has been summarized into four stages: general corrosion, corrosive ions penetration into porous and barrierlayer, self-healing in local region, coating damage.

Annealing induced structural and phase transitions in anodic aluminum oxide prepared in oxalic acid electrolyte

Anodic aluminum oxide (AAO) films with uniform cylindrical pores are widely used as templates and membranes. The annealing of initially amorphous AAO enhances its chemical stability, but simultaneously changes its morphology and phase composition. Here we study the effect of annealing in the temperature range up to 1150 °C on structural and phase transitions in porous AAO films prepared by Al anodization in oxalic acid. Full-profile analysis of high-resolution X-ray diffraction patterns using the Rietveld method reveals the sequence of phase transformations (amorphous alumina → a mixture of γ-Al2O3 and θ-Al2O3 → a mixture of γ-Al2O3, δ-Al2O3, and θ-Al2O3 → α-Al2O3) and is used for quantitative phase analysis. Decomposition of oxalate-impurities, induced by the AAO crystallization, is studied using combined Fourier-transform infrared spectroscopy and thermogravimetry analysis. The removal of impurities results in the formation of mesopores in the AAO cell walls with a consequence increase in the specific surface area up to 80 m2·g−1. The apparent activation energies of the removal of water (~35 kJ·mol−1) and of the decomposition of carbon-containing impurities (~350 kJ·mol−1) are calculated. Morphology-dependent kinetics of the impurities removal is described in the framework of the limited mass-transport of oxalate decomposition products through the cell walls.

Tailoring Surface Hydrophilicity Property for Biomedical 316L and 304 Stainless Steels: A Special Perspective on Studying Osteoconductivity and Biocompatibility.

Stainless steels used as metal implants in the medical field have been attracting intensive attention due to their advantages in mechanical properties, anticorrosion properties, and cost effectiveness. Good osteoconductivity, low toxicity, and low inflammatory reactions are essential to stainless steel implant in vivo. However, there are few cases about the surface modification performed for enhancing the corrosion resistance, and there are few researches on the relationship between the surface properties of stainless steel and osteoconductivity when used as implants. This study employed 316L and 304 stainless steel for surface modification including hydrothermal treatment after acid immersion and anodizing treatment, while the as-polished stainless steel was used as a control group. Anticorrosion properties, protein adsorption properties, osteoconductivity, and anti-inflammation property of these specimens were intensively investigated in vitro and in vivo. It was found that specimen subjected to hydrothermal treatment at 230 °C after immersion in 18 M H2SO4 had the lowest metal ions release, while the anodized specimen had the highest release of Fe and Cr due to corrosion. The protein adsorption amount of the specimens was positively related to the osteoconductivity, suggesting protein adsorption is the prerequisite for good osteoconductivity. The osteoconductivity decreased first and then increased with the increase in water contact angle (WCA) value. The specimen with the surface modified by hydrothermal treatment after acid immersion had the highest protein adsorption amount and the best osteoconductivity due to its superhydrophilicity property. The protein adsorption capacity and osteoconductivity for stainless steel tended to be the same as Ti alloys studied before, indicating the surface hydrophilicity property of the implanted metals was the dominant factor affecting the osteoconductivity. From an anti-inflammation perspective, the specimen with the surface modified by hydrothermal treatment after acid immersion also exhibited the lowest thickness of the fibrous capsule membrane from the in vivo tests, suggesting its advantageous biocompatibility. Thus, this research can provide new insight into the application of austenitic stainless steel for implanted material purposes.

Development of a solar reflector coating on AA6061 alloy by plasma electrolytic oxidation

A spacecraft consists of various components which will function with maximum efficiency only when their operating temperature is maintained within certain specified ranges. Passive thermal control elements play an important role in maintaining the temperature of spacecraft components within the specified ranges by suitable selection of thermo-optical properties of the surfaces namely absorptance and emittance. Plasma electrolytic oxidation of AA 6061 is studied as a method to develop a solar reflector coating for space applications. The coatings are developed by making use of a silicate-based electrolyte. The influence of electrolyte composition, average current density, processing time, positive on-time and pulse frequency on the thermo-optical behaviour of the coating is studied. The thickness of the PEO coating is optimized so as to attain thermo-optical properties similar or better than conventional sulphuric acid anodizing. The optimized coating is subjected to adhesion and humidity tests as well as various space simulation tests such as thermal cycling and thermo-vacuum performance tests to evaluate the suitability of the coating as a thermal control surface for space application. Coatings obtained by PEO process and conventional sulphuric acid anodizing are further characterized using SEM, EDX, XPS, XRD and nanoprofilometry to have a comparative study of their morphology, microstructure and composition.

Alkaline Corrosion-Resistant Anodic Aluminum Oxide Formed By Etidronic Acid Anodizing

A newly discovered electrolyte for anodizing aluminum, etidronic acid (CH3C(OH)[PO(OH)2]2), operates at high voltages of more than 200 V, and ordered porous alumina measuring 400-670 nm in cell diameter (interpore distance) can be fabricated via constant voltage anodizing. Because such porous alumina film formed at high voltages possesses a thick barrier layer, etidronic acid anodizing may be useful for corrosion protection of aluminum. Here, we describe the alkaline corrosion-resistant porous alumina formed by high voltage anodizing in an etidronic acid solution, and its hydration behavior in boiling water was investigated. Highly pure aluminum plates (99.999 wt%) were anodized in 0.3 M sulfuric acid, 0.3 M oxalic acid, 0.3 M citric acid, and 0.3 M etidronic acid solutions (293 K) at a constant current density of 30 Am-2 or a constant voltage of 250 V. The anodized specimens were immersed in a 2.5 M NaOH solution (293 K). The nanostructural changes were examined by electrochemical impedance spectroscopy (EIS). The anodized specimens were immersed in boiling water to seal the pores in the porous alumina film. The surface and cross-section of the specimens were characterized by field-emission scanning electron microscopy (FE-SEM) The plateau voltages during anodizing aluminum at a constant current density of 30 Am-2 in sulfuric and etidronic acid solutions exhibited approximately 16 V and 197 V, respectively. As the specimen anodized in sulfuric acid was immersed in a 2.5 M sodium hydroxide solution, H2 gas evolution was observed from the surface at the beginning of immersion, and the amount increased with the immersion time. In contrast, the specimen anodized in etidronic acid did not result in hydrogen gas evolution during immersion until 8 min. Here, the capacitance (Cb ) is inversely proportional to the thickness of the barrier layer. Figure 1 shows the changes in the reciprocal Cb with the immersion time, ti . Complete dissolution of porous alumina formed in etidronic acid takes 15 times longer than dissolution of the alumina formed by sulfuric acid anodizing due to the formation of a thick barrier layer. As the porous alumina formed by etidronic acid anodizing is immersed in boiling water, plate-like hydroxides were formed at the bottom of the pores in the initial immersion stage. The thickness of the hydroxide layer increased with the immersion time, and the nanopores are completely sealed by long-term immersion. Figure 1

Fabrication of Sticky and Slippery Aluminum Alloys Based on Anodic Alumina Nanofibers

Anodizing aluminum in a pyrophosphoric acid solution (H4P2O7) causes the formation of numerous anodic alumina nanofibers. The nanofiber-covered aluminum surface exhibits superhydrophilicity measuring less than 10° in water contact angle (WCA). In contract, as the alumina surface is modified with a self-assembled monolayer (SAM), the WCA value changes to show superhydrophobicity measuring more than 150°. In the present investigation, the fabrication of highly sticky and slippery aluminum alloys was achieved by optimizing the nanostructure of anodic alumina nanofibers formed on the surface. Commercially available 3004 aluminum alloys (composition: 1.0-1.5 wt% Mn, 0.8-1.3 wt% Mg, small amounts of Cu, Zn, Fe, and Si) were chemically polished in a 2.5 M NaOH solution at 333 K for 5 min, and then were immersed in a 4.0 M HNO3 solution at room temperature for 30 s. The polished specimens were immersed in a pyrophosphoric acid solution (74.0 wt%) at 293 K, and then were anodized at a constant voltage of 75 V for up to 60 min. After anodizing, the specimens were immersed in a 1.5 mM 3,3,4,4,5,5,6,6,7,7,8,8,8,-tridecafluorooctylphosphonic acid (FOPA)/ethanol solution at 313 K for 48 h. The slipping behavior of the water droplet formed on the anodized specimens was examined by advancing and receding contact angle measurements using an optical contact angle meter. As the aluminum alloys were anodized in a pyrophosphoric acid solution, numerous anodic alumina nanofibers with the insoluble intermetallic compounds were formed on the surface. The length of the nanofibers increased with the anodizing time, and many nanofiber-tangled intermetallic particles were exposed to the surface. Figure 1 shows the changes in the advancing contact angle, θ adv, and the receding contact angle, θ rec, on the SAM-modified aluminum surface with anodizing time, t a. The θ adv value increased to approximately 170° by pyrophosphoric acid anodizing, and this superhydrophobicity was maintained upon further anodizing up to 60 min. On the other hand, the θ rec value drastically changed with anodizing time. As a result, the contact angle hysteresis (θ adv - θ rec) was also changed with anodizing time. Therefore, the adhesion interaction between the water droplet and the aluminum surface can easily be controlled by pyrophosphoric acid anodizing. Figure 1

Characterization and properties of AA6061-based fiber metal laminates with different aluminum-surface pretreatments

In this study, an Al/CFRP/Al laminates was prepared with three types of aluminum alloy AA6061 surface treatments (sanding, anodizing, and surface modification) to improve the metal–composite interface (MCI) strengths. The results showed that the shear strengths of Al/CFRP/Al laminates modified by silane coupling agent and pretreated by phosphoric acid anodizing were similar, approximately 50 MPa, which were significantly higher than those subjected to sandpaper-sanding pretreatment (38 MPa). Results of scanning electron microscopy (SEM) revealed that the nanoscale porous anodized film produced on the AA6061 surface after anodizing pretreatment enhanced the wettability of CFRP on AA6061 sheets, leading to strong interfacial bonding. XPS analysis showed that a new chemical bond, AlOEP, appeared at the interface between CFRP and anodized AA6061, which clearly indicated that the anodized layer could enhance the mechanical anchoring effect and promote its chemical reaction. And the chemical bonds of AlOSi and SiC were found at the interface between CFRP and silane-modified AA6061, thereby proving the existence of a silane flexible layer, which enabled the adjustment of the thermal expansion coefficient mismatch between AA6061 and CFRP and the improvement in the stability of the mechanical properties of Al/CFRP/Al laminates.

Fabrication of alumina with ordered tapered-nanopore nested in micro-bowl hierarchical structure by a combined anodization

We report that porous anodic alumina (PAA) with ordered tapered-nanopore nested in micro-bowl hierarchical structure can be facilely and controllably fabricated by a combined anodization process. It includes three main steps: I, stable anodization in citric acid to fabricate micro-bowl; II, mild anodization and chemically dissolving PAA to fabricate nanopit pattern; III, multi-step mild anodization and etching pore-widening to fabricate tapered-nanopore. Although the used anodization technology in each step is well established, the smart combination for realizing hierarchical structure is unreported but very effective. It is found that the original interpore distance of the micro-bowl obtained by stable anodization in citric acid can be enlarged by the followed mild anodization, which can be tuned from 0.88 μm to 1.3 μm. The structural parameters of tapered-nanopore can be tailored by changing the mild anodization conditions. Because of the curvature of the micro-bowl, the average number of the tapered-nanopore can be as high as 1.68 × 1015/cm2, which is about 1.5 times more than that (1.16 × 1015/cm2) on the flat surface. This method is simple and effective, which opens a door for boosting investigations into the physical and chemical properties of micro- and nanostructure made of metal or polymer materials as combining with nanoimprinting or electrochemical deposition.

The effect of chemical additives in phosphoric acid anodization of aluminum-tantalum thin films

Biosensor development has relied on the process of anodization of sputtered aluminum‑tantalum thin films to develop specific optical properties for interference color generation. The anodization of thin sputtered films of aluminum (140 nm) on tantalum (230 nm) on silicon was completed in 0.4 M phosphoric acid under potentiostatic conditions (4 V) and with various additives: 0.1 M and 0.4 M citric acid, 3% (v/v) and 10% (v/v) of a commercial anodizing solution consisting of glycerol and glycolic acid, and 0.1 M and 0.4 M oxalic acid. The microstructural and optical properties of these films were analyzed using scanning electron microscopy, X-ray diffraction, and ellipsometry. The interference colors produced by the anodic aluminum and tantalum oxides on top of the tantalum metal layer were also observed. The addition of 0.1 M citric acid, 3% (v/v) glycerol and glycolic acid-based solution, and 0.1 or 0.4 M oxalic acid all produced changes to the porous microstructure of the anodic alumina, including lower roughness and more homogeneous surfaces by inhibition of the dissolution from phosphoric acid. Oxalic acid acted as the strongest inhibitor and significantly reduced surface roughness and pore size, increased the composite refractive index of the anodized film, and significantly changed the interference colors compared to films where no additive was used.

Complex influence of temperature on oxalic acid anodizing of aluminium

Two-step aluminium anodizing is widely used to prepare oxide films with a highly-ordered porous structure through the whole thickness. It can be realized solely at relatively low values of current density in the kinetic anodizing regime that makes this process extremely time-consuming. Temperature is an important thermodynamic parameter which is able to accelerate chemical reactions and mass-transport and, thus, could be suggested as an effective tool to control the growth rate of anodic alumina. Here we report a systematic study of the porous anodic alumina films formation in 0.3 M oxalic acid electrolyte in a wide temperature range. The influence of electrolyte temperature on the kinetics of aluminium anodizing and on the morphology of the obtained anodic alumina films is addressed quantitatively. Current transients registered at various temperatures are used for the calculation of the apparent activation energy of the anodization process in both mild and hard anodizing regimes. In the case of thick oxide films and high electrolyte temperature, the increase in diffusion current contribution leads to switching the kinetically controlled anodizing to the mixed regime which results in destroying the hexagonal pore ordering. Based on the experimental findings, rational electrolyte temperatures and porous layer thicknesses for the first and second anodizing steps are proposed as a guide for express preparation of alumina films with well-ordered porous structure.

Effect of shot peening and anodizing on fatigue crack growth of aircraft material Al 7050-T7651

The rate of fatigue crack propagation of the 7050-T7651 aircraft material subjected to automatic shot peening machine and chromic acid anodizing (CAA) has been studied and compared with previous research results. Al 7050-T7651 is made into specimens according to ASTM E647 standard treated with automatic shot peening machine (with steel shot material, 0.017inch diameter, shot flow 30%, 3 bar pressure, Almen intensity 0.0082 A with 100 mm shooting range and 90° angle of shot) and CAA (operating standard) in surface treatment area of Indonesian Aerospace. The fatigue cracking test with a load of about 200 kg, with a stress ratio of R = 0.1. The results of the fatigue crack growth test resulted in the constant of Paris A = 3.654 × 10−9 and n = 1.67, indicating that the automatic shot peening machine and chromic acid anodizing treatment decreased the fatigue life and increased the fatigue crack growth rate compared to the automatic shot peening machine, manual machine with or without CAA, and without treatment.

Surface Treatment for Improving Durability of Aluminum-Lithium Adhesive-Bonded Joints under Hot-Humid Exposure

The performance of adhesive-bonded joints, which are being increasingly used in the aerospace and automotive industries, under hot-humid conditions remains largely unknown. The effect of surface treatments on the strength durability of aluminum-lithium (Al-Li) alloy adhesive-bonded joints under hot-humid exposure was investigated. Varied surface characteristics were achieved by different mechanical and chemical treatments; combined mechanical and phosphoric acid anodization (PAA) treatments were also used. The adhesive-bonded joints were then exposed to a hot-humid environment. The surface morphology, strength degradation, failure modes, and corrosion resistance of the substrates were analyzed. The results indicated that the combined PAA/mechanical method improved the joint durability under hot-humid exposure. The treated surface, with a roughness of 2.85 μm, exhibited the best durability, losing only 6% of strength after exposure; the failure mode remained cohesive-failure dominant. The durability enhancement was attributed to the porous and moderate rough surface characteristics, which protected the substrate from corrosion and decreased the rate of moisture diffusion from the bonding interface, thereby reducing the degradation of the bonding interface and improving the durability of the joint.

Effect of combined surface treatment on the adhesion performance of aluminium-lithium alloy

Herein we investigated the effect of various surface treatments, especially the combined surface treatment of grit-blasting and phosphoric acid anodization (PAA), on the surface characteristics and the adhesion performance of aluminium-lithium alloy sheets. For the combined surface treatment, rough surfaces were firstly created by grit-blasting to increase the surface area available for anodization. Next, porous structures were produced on the grit-blasted surfaces by PAA. The surface characteristics, surface wettability, fracture morphology, and shear strengths of samples subjected to different surface treatments were compared and analyzed. The effect of surface roughness on the bonding strength of aluminium-lithium alloys subjected to combined treatments was also investigated. The experimental results showed that combined treatment provided the best wettability and single-lap joint performances, with the highest surface free energy of 81.4 mJ/m2 and shear strength of 40.8 MPa.

Effects of applying a combination of surface treatments on the mechanical behavior of basalt fiber metal laminates

The surface treatment of metals has a great role on the adhesion of the metals to the polymers. There are various surface treatment methods for adhesive joint applications. However, the effect of the combination of surface treatment methods on the mechanical behavior of adhesive joints has not been extensively studied. In this study, the effects of applying a combination of surface treatments on the flexural and Charpy impact behavior of fiber metal laminates (FMLs) were investigated. The surface treatments included forest product laboratory etching (FPL), sulfuric acid anodizing (SAA), sandblasting, sandblasting + FPL and sandblasting + SAA. The FMLs were made from Al2024-T3, basalt fibers and epoxy. Scanning electron microscopy (SEM) was used to study the surface morphology of the Al2024-T3 laminates and fracture surface of the samples. Furthermore, the surface roughness of the Al2024-T3 sheets after different surface treatments were evaluated using profilometry. Results showed that the adhesion of Al2024-T3 to polymeric layers was significantly affected by various surface treatments. Results of bending tests indicated that the highest bending strength and strain to failure values were respectively achieved for the SAA and sandblast treated samples. On the other hand, although there was a slight improvement in the bending strength, the application of SAA or FPL etching after sandblasting caused a negative effect on the strain to failure value of the samples. However, impact test findings showed that the combination of FPL or SAA treatments after sandblasting rendered positive effects on the low-velocity impact behavior of the FMLs.

(Invited) Stable and Conductive Anhydrous Proton Conducting Membranes Based on Polycations Blended with Polybenzimidazole

This talk primarily focuses on anhydrous, mild temperature (100 to 250 °C) proton conductors composed of polycation polymers, typically used as anion exchange membranes, blended with polybenzimidazole (PBI). These moderate temperature membranes are envisioned for fuel cell systems that operate with hydrogen from steam-reformed methane. Evaluating polycation membrane variants alone demonstrated lower proton conductivity when compared to PBI doped with phosphoric acid (H3PO4) and sulfuric acid. PBI doped with phosphoric acid, on the other hand, was observed to be unstable above 160 °C because of H3PO4 boiling and evaporation. Plus, the PBI-H3PO4membrane loses its acid due to leaching if condensed water is present (i.e., lack of robust operation if the cell drops below 100 °C). To overcome these problems, polycation polymers, were blended with polybenzimidazole (PBI) and these membranes routinely showed conductivity values as high as 0.18 S cm-1and were stable under dry and wet conditions and with thermal stability up to 250 °C. These membrane composites were also assessed with other types of doped acids (e.g., phosphoric acid, methanesulfonic acid, p-toulenesulfonic acid, trifluoroacetic acid, and sulfuric acid) to promote the Faradaic reaction kinetics at low pH (i.e., pH values below 0). The talk will close with our recent efforts to pattern polymer electrolyte membrane surfaces to make high surface area bipolar junction interfaces. It is envisaged that an acidic anode and alkaline cathode with a bipolar membrane offers a pathway forward for very low platinum loading fuel cells. Figure 1

Wettability and adhesion of nanotubes applied to the surface of titanium implants by anodic oxidation

Background: A good implant surface is crucial for osseointegration. Many types are described in literature like double acid etching, SLA and anodization.

Sub-10 nm porous alumina templates to produce sub-10 nm nanowires

Abstract The versatility of Anodic Aluminum Oxide has led to the development of a variety of templates with ranging sizes, periodic modulations, and network-like architectures. These templates allow for the nanostructuration and study of new meta-materials, with interesting and important properties enhanced through size-reduction effects. In this work, we further extend the utility of these templates through the use of current anodization in concentrated Sulfuric acid and 25% V/V of ethanol under low current density values, obtaining small pore architectures with sub-10 nm features. In addition, polymer infiltration was performed as a proof of concept application, resulting in 8 nm nanowires. The templates reduced sizes allow for their application in the search for stable, extremely small diameter nanowires, and also for their use as scaffolds or filters.

Effect of Potential on Corrosion Behavior of Tartaricsulphuric Acid Anodized 7075 T6 Aluminum Alloys

Anodizing of aluminum alloy in tartaric-sulphuric acid (TSA) is studied as an alternative to replace chromic acid anodization (CAA) to obtain more environmentally-friendly process. Bare 7075 T6 aluminum alloy specimens were anodized in TSA and subsequently protected by boiled water sealing treatment. The TSA solution used contains 86,76 gpl tartaric acid and 44 gpl sulphuric acid at 37°C. Some specimens are anodized in CAA as comparison. In this research, the effect of anodization potential of 7075 T6 aluminum alloy in TSA on the thickness, weight, and corrosion resistance of anodize layer are studied. Corrosion resistance test was carried out by conducting salt spray test for 96 hours and corrosion potential and current density measurement using potentiostat. The morphology and chemical composition of the sealed anodize layer were evaluated by scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The results showed that the thickness and weight of the anodize layer increases as the anodization potential increases. The best corrosion resistance is achieved by 7075 T6 aluminum alloy specimen with potential anodization of 15 V.

Effects of two nanotopographies of ultraviolet-treated titanium implant surface on macrophage behaviour and inflammatory cytokines secretion

Objective: To investigate the effects of two nanotopographies of ultraviolet (UV)-treated titanium surface on macrophage biological behaviour and inflammatory cytokines secretion, and to provide basis for clinical application of UV-treatment in dental implant modification. Methods: Titanium disks were allocated into two groups. Samples in one group were acid-etched in hydrofluoric acid (Acid Ti group), and those in the other group were acid-etched and anodized (Anodization group) to form two nanotopographies respectively. The surface morphology was evaluated by field-emission scanning electron microscopy (FE-SEM). The samples were stored in the dark for 8 weeks. Thirteen samples from each group were exposed to UV-irradiation for 48 h (Acid Ti+UV group and Anodization+UV group), UV-untreated samples from Acid Ti and Anodization groups served as control. Hydrophilicity of samples was measured using contact angle measuring device. After 4, 24 and 72 h of incubation, macrophage cell adhesion and proliferation were conducted using cell counting kit-8. Cytokine/chemokine secretions [tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α)] were measured from cell culture supernatants at 24 and 72 h using magnetic luminex assay. Cell morphology was examined using FE-SEM after 2 h of incubation. Results: Micropitted/nanopillar and micropitted/nanotubular topographies were observed in Acid Ti group and Anodization group respectively. Contact angles in Acid Ti+UV and Anodization+UV groups (20.2°±2.8° and 0.0°±0.0°) were significantly smaller than those in the Acid Ti and Anodization groups (P<0.05). Cell adhesion and proliferation in all groups at 4 and 24 h showed no difference (P>0.05). Cell proliferation in Acid Ti+UV and Anodization+UV groups at 72 h were (0.92±0.13) and (1.10±0.08) respectively, which were significantly higher than those in Acid Ti and Anodization groups. TNF-α concentration in Acid Ti+UV and Anodization+UV groups at 72 h were (1.03±0.11) and (0.87±0.10) ng/L, MCP-1 were (301.7±50.3) and (240.8±18.7) ng/L, MIP-1α were (224.9±30.6) and (233.9±14.9) ng/L respectively, which were significantly lower than those in Acid Ti and Anodization groups (P<0.05). Conclusions: UV treatment can increase hydrophilicity of two titanium surface topographies, especially of Anodization+UV group. UV-treated titanium surfaces can promote macrophage proliferation and reduce the inflammatory response in vitro.