Roughness Treatment Research Articles

Effect of different surface roughening treatment on polyether ether ketone and acrylic resin bonding: A pilot study.

As polyether ether ketone (PEEK) is a relatively new material in dentistry, its bonding properties with regard to dental acrylic base materials are not fully known. To ensure the long-term success of removable dentures with a PEEK framework, the base materials must be well bonded to each other. The study aimed to investigate the effects of different kinds of surface roughening treatment on PEEK and acrylic resin bonding. Eighty PEEK specimens (N = 80) were randomly divided into 5 groups (n = 16 per group) and subjected to various surface roughening treatment (control, grinding, sandblasting, tribochemical silica coating (CoJet), and sulfuric acid etching). Heat-polymerized acrylic resin was applied to the treated surfaces of the PEEK specimens. The shear bond strength (SBS) test, environmental scanning electron microscopy (ESEM) analysis and three-dimensional (3D) surface topography analysis were performed. The statistical analysis of the data was conducted using the analysis of variance (ANOVA) and Tukey's multiple comparison test. The one-way ANOVA showed significant differences in the SBS values between the groups (p = 0.001). Sandblasting, tribochemical silica coating and sulfuric acid etching resulted in high SBS values (p = 0.001). The highest SBS values were observed in the sulfuric acid etching group (8.83 ±3.63 MPa), while the lowest SBS values were observed in the control group (3.33 ±2.50 MPa). The additional roughening treatment applied to the PEEK surface increases the bond strength with heat-polymerized acrylic resin.

Influence of ultrasonic shot peening on the surface acid etching behavior of pure titanium

Due to its exceptional combination of mechanical and biocompatible qualities, titanium (Ti) is frequently employed in the dental and bone implantation areas. Ti material is frequently subjected to surface roughening treatment to improve biocompatibility. This research designed and applied the ultrasonic shot peening and acid etching (USPA) method to obtain topographical surface. The microstructure and element distribution were determined using SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive Spectrometer), respectively. The phase structure was identified using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The outcomes demonstrated that employing USPA, a rough and porous surface could be obtained. By changing the USP parameters, deep holes with a diameter of a few microns and step-shaped structures closed to the nanoscale might be produced.

In vitro comparative study between adhesion forces obtained on zirconia ceramic micromechanically treated with femtosecond laser (1027nm), carbon dioxide laser (10,600nm), and aluminum-oxide particles.

Conventional surface roughening treatments used for silica-based ceramics in order to improve subsequent adhesion become unreliable for zirconia ceramics. Laser conditioning can be a good alternative. The purpose of this in vitro study was to compare conventional (macro) shear bond strength (SBS) values obtained between resin composite and zirconium oxide ceramic samples grouped according to different micromechanical treatments received, and examine differences in surface roughness. One-hundred and fifty disks of sintered zirconia were randomly divided into 5 groups and roughened as follows: (1) Group NOT, no surface treatment; (2) Group APA, abraded with 50-μm aluminum-oxide (Al2O3) particles; (3) Group TBS, abraded with 30-μm aluminum-oxide particles covered with silica; (4) Group CO2, irradiated with a CO2 laser which emitted in continuous wave mode at 3 W of power; and (5) Group FEM, irradiated with a pulsed femtosecond laser, with an incident energy of 10μJ, a frequency of 1000Hz, and a fluence of 1.3kJ/cm2. All surfaces were treated with a MDP-containing adhesive/silane coupling agent mixture upon which were prepared and light polymerized composite resin cylinders. Shear bond strength was measured and samples were observed by scanning electron microscopy (SEM). Statistically significant differences (p < 0.05) were found among all groups, except between CO2 and FEM, which showed the highest adhesion values (15.12 ± 2.35MPa and 16.03 ± 2.73MPa). SEM revealed differences in surface patterns. CO2 laser irradiation can be an alternative to sandblasting, although it could also weaken the ceramic. Suitable surface patterns on zirconia ceramics can be obtained with ultrashort pulsed radiation emitted by a pulsed femtosecond laser.

Effects of thickness and polishing treatment on the translucency and opalescence of six dental CAD-CAM monolithic restorative materials: an in vitro study

BackgroundComputer-aided design and computer-aided manufacturing (CAD-CAM) materials for prosthetic is gaining popularity in dentistry. However, limited information exists regarding the impact of thickness and roughening treatment on the optical properties of contemporary CAD-CAM restorative materials. This study aimed to quantitatively evaluate the translucency and opalescence of six dental CAD-CAM materials in response to different thicknesses and roughening treatments.MethodsSix dental CAD-CAM materials, lithium disilicate glass–ceramic (IPS e.max CAD, LS), polymer-infiltrated ceramic (VITA Enamic, VE), resin-nano ceramic glass–ceramic (LAVA Ultimate, LU), polymethyl methacrylate (Telio CAD, TE), and two zirconia reinforced lithium silicate (VITA Suprinity, VS, and Celtra Duo, CD), in shade A2 were prepared as 12 × 12mm2 specimens of four thicknesses (0.5mm, 1.0mm, 1.5mm, and 2.0mm) (N = 240, n = 10). After three different treatments (polished, roughened by SiC P800-grit, and SiC P300-grit), the translucency parameter (TP00) and opalescence parameter (OP) were measured with a spectrophotometer (VITA Easyshade V). The surface roughness was analyzed with a shape measurement laser microscope. The data were analyzed using a MANOVA, post hoc Tukey–Kramer test, the t test, and regression analysis (α = .05).ResultsThe TP00 and OP were significantly influenced by material type, thickness and roughening treatment (P < .05). TP00 showed a continues decline with increasing thicknesses, while the variations of OP were material-dependent. TP00 ranged from 37.80 (LS in 0.5mm) to 5.66 (VS in 2.0mm), and OP ranged from 5.66 (LU in 0.5mm) to 9.55 (VS in 0.5mm). The variations in TP00 of all materials between adjacent thicknesses ranged from 2.10 to 15.29, exceeding the acceptable translucency threshold except for LU. Quadratic and logarithmic regression curves exhibited the best fit for TP00 among the materials. Compared to polished specimens, rougher specimens exhibited lower TP00 and higher OP in all materials except for LS (P < 0.05). Roughening with P300-grit decreased TP00 and OP by an average of 2.59 and 0.43 for 0.5mm specimens, and 1.26 and 0.25 for 2.0mm specimens, respectively.ConclusionsVariations in translucency caused by thickness and roughening treatment were perceptible and may be clinically unacceptable. Careful consideration should be given to the selection of CAD-CAM materials based on their distinct optical properties.

Roughening Action of NaCl-Electrolytic Oxidizing Water on Rolled Surface of Permalloy 45

This paper discusses roughening action of NaCl-electrolytic oxidizing water (hereinafter it is referred as EO water) on the rolled surface of permalloy 45. Firstly, in the case of roughening treatment by immersion into NaCl EO water, the experiment to confirm the presence or absence of local non-uniform roughening areas on the rolled surface after roughening treatment was carried out. The results showed that unlike the polished surface, the rolled surface does not generate local non-uniform roughening areas. Next, experiments on the immersion time into NaCl EO water and the roughening performance was carried out. The results showed that the rolled surface can be uniformly roughened by immersion into NaCl EO water for 20 minutes with ultrasonic, but it cannot be roughened by HCl solution. Lastly, experiments on NaCl EO water elapsed time from generation and roughening performance was carried out. The results showed that even after one week has passed from generation of NaCl EO water, the roughening action to the rolled surface of permalloy 45 hardly changes. The presence of oxygen nanobubbles in the NaCl EO water is considered to be one of the major factors. By this study, we received the suggestion that NaCl EO water could be applied to the surface roughening treatment of permalloy 45.

Enhancing luminous flux and color rendering of laser-excited YAG:Ce3+ single crystal phosphor plate via surface roughening and low-temperature sintering a CaAlSiN3:Eu2+ phosphor-in-borate glass

Y3Al5O12:Ce3+ (YAG:Ce3+) single crystal phosphor (SCP) exhibits high internal quantum efficiency (IQE) and excellent thermal conductivity and stability. Such properties are promising in high-power laser-excited white lighting applications. However, YAG:Ce3+ SCP usually shows low luminous flux and color rendering index (CRI, Ra) when excited by a transmissive laser. In this study, a self-designed three-integrating sphere system was established to characerize the optical performances of YAG:Ce3+ SCP palates under both the reflective and transmissive 455 nm blue laser excitations. Next, its luminous and color rendering properties under transmissive laser excitation were improved by surface roughening treatment and sintering of a CaAlSiN3:Eu2+ (CASN:Eu2+) phosphor-in-borate glass (PiBG) layer. The results revealed that: (1) When the YAG:Ce3+ SCP was excited by blue laser, its forward luminous flux was considerably lower than the backward one; (2) Under transmissive excitation, its luminous flux rolled up with the maximum increase rate of 109.19% when the averaged roughness (Ra) increased from 0.35 to 5.40 μm; (3) After sintering the CASN:Eu2+ PiBG layer on the roughening YAG:Ce3+ SCP, its luminous flux, CRI increased by 31.48% and 117.14%, and its color fidelity index (CFI, Rf) reached up to 82 under the transmissive 3.03 W blue laser excitation.

Repair of Bulk-Fill and Nanohybrid Resin Composites: Effect of Surface Conditioning, Adhesive Promoters, and Long-Term Aging.

The aim of the study was to investigate the effect of different repair procedures on the repair bond strength of bulk-fill and nanohybrid resin composites after different aging periods. The resin composite blocks (8 × 8 × 4 mm3) were prepared from a bulk-fill (reliaFIL Bulk) and a nanohybrid (reliaFIL LC) resin composite and grouped according to aging duration (6 months, 1 year, and 2 years). Following aging, the blocks were assigned to different surface treatments; air-abrasion with aluminum oxide powder, roughening with a diamond bur, and no treatment. After cleansing with phosphoric acid, a silane layer (Porcelain Primer) was applied on the surface of half of the specimens in each group. The specimens were subdivided into two groups (n = 5): Scotchbond Universal (3M Oral Care) and All-Bond Universal (Bisco). The blocks were repaired with the nanohybrid composite (8 × 8 × 8 mm 3). The repaired specimens were stored in distilled water (37 °C/24 h) and segmented into beams. Half of the beams were immediately subjected to microtensile μTBS testing (1 mm/min), while the other half was stored in distilled water (37 °C) for 6 months before testing. Failure modes were analyzed using stereomicroscope and SEM. Statistical analyses were performed with ANOVA and least significant difference tests (LSD) tests (p = 0.05). The extension of aging periods (6 months, 1 year, and 2 years) reduced the repair bond strength in some groups for both resin composites (p < 0.05). The air-abrasion and bur roughening improved the repair bond strength (p < 0.05). The silane application did not influence the repair bond strength and durability (p > 0.05). There was no difference among the universal adhesives in the same surface treatment groups (p > 0.05). The mechanical roughening treatments are necessary for the repair of resin composite. The universal adhesives might be used for the repair of resin composites regardless of silane content without prior silane application.

Influence of NaCl-Electrolytic Oxidizing Water on Polished Surface of Permalloy Material 45

This paper discusses the influence of NaCl-electrolytic oxidizing water (hereinafter it is referred as EO water) on the polished surface of permalloy material 45. Firstly, roughening treatment experiment on polished surface of permalloy material 45 before and after heat treatment, using NaCl EO water and HCl solution with ultrasonic, was carried out. The results showed that when using HCl solution, the surface of permalloy material 45 couldn't be uniformly roughened, while when using NaCl EO water, it could be uniformly roughened. In addition, as with Na2SO4 EO water, circular non-uniform roughening areas was generated locally on the surface of test pieces after the immersion treatment. According to EDS analysis, it is due to the adhesion of abrasive (Al2O3) and component segregation. Next, in order to clarify the chemical composition of the surface layer of the test pieces and the contamination of Cl and Al, EDS mapping analysis was performed on the surface of test pieces after the immersion treatment. The results showed that similar to Na2SO4 EO water, NaCl EO water does not adversely affect the chemical composition of the surface layer of test pieces, the amount of abrasive (Al2O3) adhered is small, and there is almost no contamination by Cl. By this study, we received the suggestion that NaCl EO water could be applied to the surface roughening treatment of permalloy material 45.

Effect of Chemical Surface Texturing on the Superhydrophobic Behavior of Micro-Nano-Roughened AA6082 Surfaces.

Superhydrophobic surfaces on 6082 aluminum alloy substrates are tailored by low-cost chemical surface treatments coupled to a fluorine-free alkyl-silane coating deposition. In particular, three different surface treatments are investigated: boiling water, HF/HCl, and HNO3/HCl etching. The results show that the micro-nano structure and the wetting behavior are greatly influenced by the applied surface texturing treatment. After silanization, all the textured surfaces exhibit a superhydrophobic behavior. The highest water contact angle (WCA, ≈180°) is obtained by HF/HCl etching. Interestingly, the water sliding angle (WSA) is affected by the anisotropic surface characteristics. Indeed, for the HF/HCl and the HNO3/HCl samples, the WSA in the longitudinal direction is lower than the transversal one, which slightly affects the self-cleaning capacity. The results point out that the superhydrophobic behavior of the aluminum alloys surface can be easily tailored by performing a two-step procedure: (i) roughening treatment and (ii) surface chemical silanization. Considering these promising results, the aim of further studies will be to improve the knowledge and optimize the process parameters in order to tailor a superhydrophobic surface with an effective performance in terms of stability and durability.

Performance of Carbon-Nickel Composite Coatings on Laser Surface Roughened Aluminum Foils for Supercapacitor Current Collectors

Surface-engineered aluminum current collectors were developed through laser-based surface modification methods. Their performances as current collectors in supercapacitors clearly outperformed state-of-the-art carbon-coated commercial foils and were close to ideal gold foils, thanks to the enhanced interfaces provided by their engineered surfaces. Surface modifications included roughening by laser ablation in high vacuum, and coating with a carbon-nickel (C0.97Ni0.03) composite thin film deposited using pulsed laser deposition. The main improvement was obtained after coating the aluminum foil with the carbon-nickel protective layer, which was attributed to the almost pure sp2 bonding state of the carbon and a mostly metallic nickel phase. The surface roughening treatment further decreased the interface resistance by providing a higher contact surface and a better mechanical anchorage of the active materials layer. The combination of laser roughening in vacuum conditions and subsequent deposition of an electronically conductive protective coating was therefore demonstrated as an efficient approach to improve the performance of current collectors for supercapacitors.

Wearable and self-powered sensors made by triboelectric nanogenerators assembled from antibacterial bromobutyl rubber

Energy, information, and materials are the three main factors required for the survival and development of modern humankind, with energy being the cornerstone of all development. In recent years, self-powered devices have received widespread attention. As a new generation device, Triboelectric nanogenerators (TENGs) assembled from flexible materials possess the characteristics of flexible design, low-cost, stable output performance, etc., and can be widely used in wearable and self-powered medical detection sensors of human body. In this paper, flexible bromobutyl rubber (BIIR) and PET were used as friction materials, and assembled into arched vertical contact-separation triboelectric nanogenerators following various film formation and surface roughening treatments. The treatment and assembly methods of the friction materials were studied in order to obtain the best power generating effects. In addition, due to the biocompatibility and intrinsic antibacterial property of BIIR films, the fabricated triboelectric nanogenerator was also applied to wearable self-powered sensor equipment, proving its potential in the fields of identification and gait analysis. The manuscript described the triboelectric nanogenerators assembled by bromobutyl rubber (BIIR) and PET, which has intrinsic antibacterial performance and high force detection sensitivity. It can be used in wearable and self-powered sensors. • Ÿ Intrinsic antibacterial BIIR films were prepared by electrospinning and assembled into wearable and self - powered TENG. • Ÿ The BIIR-based TENGs is capable of energy-harvesting and signal recognition for identification and gait analysis. • The BIIR-based TENGs are easy to prepare and have the potential for large-scale industrial production.

Chemical and Mechanical Roughening Treatments of a Supra-Nano Composite Resin Surface: SEM and Topographic Analysis

Background: Repairing a restoration is a more advantageous and less invasive alternative to its total makeover. The aim of this study was to analyze the effects of chemical and mechanical surface treatments aimed at increasing the roughness of a supra-nano composite resin. Methods: 27 cylindrical blocks of microhybrid composite were made. The samples were randomly divided into nine groups (n = 3). The samples’ surface was treated differently per each group: acid etching (35% H3PO4, 30 s and 60 s), diamond bur milling, sandblasting and the combination of mechanical treatment and acid etching. The samples’ surface was observed by a scanning electron microscope (SEM) and a confocal microscope for observational study, and surface roughness (Ra) was recorded for quantitative analysis. Results: The images of the samples sandblasted with Al2O3 showed the greatest irregularity and the highest number of microcavities. The surfaces roughened by diamond bur showed evident parallel streaks and sporadic superficial microcavities. No significant roughness differences were recorded between other groups. The difference in roughness between the control group, diamond bur milled group and sandblasted group was statistically significant. (p &lt; 0.01). Comparison between the diamond bur milled group and the sandblasted group was also significant (p &lt; 0.01). Conclusion: According to our results, sandblasting is the best treatment to increase the surface roughness of a supra-nano composite.

Effect of Surface Roughness on Pitting Corrosion of AZ31 Mg Alloy

Magnesium is a highly desired material for multiple applications including automotive, aircraft, and biomedical components due to its high strength to weight ratio, non-toxicity, and its good machinability. The main drawback of magnesium use is its poor resistance to corrosion. The goal of this experiment was to determine the effect of surface roughening treatments on the rate of corrosion and to characterize the resultant magnesium oxide (MgO) and brucite (Mg(OH)2) corrosion products. Three samples of AZ31 alloy with varying initial surface roughness were exposed to simulated marine conditions using a salt fog chamber for 672 h. The salt fog experiments used a 3.5 wt.% NaCl solution and were conducted in accordance with the ASTM B117 test protocols. One sample was tested in an as-received state, served as the control, another sample was roughened using a grit blaster, and another was polished to a mirror finish. Formed oxide scales were characterized using scanning electron microscopy, X-ray diffraction, and energy dispersive spectroscopy. The samples with a higher roughness underwent the severest corrosion and ensuing formation of the thickest oxide layers. The results indicate that the initial surface roughness has a profound effect on the resulting severity of pitting corrosion in Mg alloys and that mechanical polishing can substantially reduce the propensity for uniform and pitting corrosion to occur.

Silane Effect of Universal Adhesive on the Composite-Composite Repair Bond Strength after Different Surface Pretreatments.

This study investigated the impact of a separate silanization step on the repair bond strength of composite substrates using a universal adhesive after various mechanical surface treatments. Composite specimens were aged and exposed to the following mechanical roughening treatments: diamond bur abrasion, aluminum oxide sandblasting, or silica coating. The specimens were then either left untreated or conditioned with universal adhesive (Scotchbond Universal), or a silane coupling agent was applied before the use of the universal adhesive or a conventional adhesive (Optibond FL). The conditioned surfaces and fresh substrate (positive control group) were covered with repair composite, and microtensile bond strength testing was performed. The significantly highest bond strength was obtained in the positive control group. Repair bond strength of the universal adhesive applied after a separate silanization step was similar to that without prior silanization, independent of the mechanical surface treatment. Moreover, after silica coating, no significant differences in the repair bond strength were detected among the different adhesive treatments. In conclusion, a separate silanization step before surface conditioning with the universal adhesive does not enhance the repair bond strength. On silica-coated composite substrates, repair bond strength values of the universal adhesive were similar to those of the conventional adhesive.

Surface optimization of CVD grown silicon carbide interlayer on graphite for plasma sprayed yttria topcoat

Chemical Vapor Deposition (CVD) technique is employed to deposit uniform, smooth, and dense SiC interlayer over High-Density Graphite (HDG) substrate, as an interlayer for subsequent deposition of yttria (Y2O3) topcoat by Atmospheric Plasma Spray (APS) process. In any thermal spray process, since the bonding is purely mechanical interlocking, the surface roughening of smooth CVD grown SiC surface becomes essential. Different surface preparation techniques like alumina grit blasting, plasma etching, laser ablation, and chemical etching were attempted to create rough anchoring patterns on SiC surface. Chemical etching of SiC interlayer by using molten eutectic NaOH/KOH is found to be effective in introducing the desire anchoring sites for Y2O3 splats during plasma spraying. The microstructural features and surface roughness of CVD grown SiC and after subsequent surface roughening treatments were compared using SEM/EDS and profilometer, respectively. The performance and its durability evaluation were carried out by thermal cycling studies on Y2O3 coated samples with and without SiC interlayer at 1723 and 1823 K that shows considerable improvement in the life of plasma sprayed Y2O3 coating with SiC interlayer.

Electrochemically treated graphite/poly(3,4-ethylenedioxythiophene)-carbon nanotubes electrode: facile preparation and remarkable enhancement in electrochemical performances

This work reports an approach to significantly improve the supercapacitive properties of poly(3,4-ethylenedioxythiophene)-carbon nanotubes (PEDOT-CNTs) hybrid electrodes. Specifically, a facile electrochemical treatment method is put forward to roughen graphite (G). After that, the electrochemically treated graphite (EG) acts as the substrate to load the PEDOT-CNTs composites by electrochemical co-deposition. The obtained EG/PEDOT-CNTs electrode shows substantially enhanced electrochemical performances with respect to G/PEDOT-CNTs electrode, caused by optimal electron transfer pathways between PEDOT-CNTs composite films and the roughened EG substrate. Here, the EG/PEDOT-CNTs electrode achieves a high specific capacitance of 278.7 F g−1 at 1 A g−1, higher than those of PEDOT based composite electrodes in various studies reported recently. This study demonstrates that the roughening treatment of the electrode substrate is an effective approach to substantially promote the supercapacitive properties of electrodes.

Biodegradable Implantation Material: Mechanical Properties and Surface Corrosion Mechanism of Mg-1Ca-0.5Zr Alloy

Mg alloy is suitable for biomedical implants as the mechanical properties of Mg are close to those of human bone. Ca is a major element in bone and Zr has a great grain refinement effect. Hence, we developed Mg-1Ca-0.5Zr alloy (XK105) as a biodegradable biomaterial and investigated its mechanical properties and surface corrosion mechanism. The results showed that heat treatment made the secondary phase homogeneous. Tensile tests showed that the heat treatment increased ductility, and that the tensile stress results in the extrusion direction showed better ductility than that in the transverse direction because of the fiber texture and extrusion characteristics. Electrochemistry test results showed that XK105 after heat treatment had a lower corrosion rate than that before heat treatment and that of pure Mg. XK105 after heat treatment formed a calcium phosphate layer after immersion in simulated body fluid; this layer protects Mg from corrosion. Surface roughening treatment increased corrosion because pits on the surface promoted pitting corrosion. This study developed Mg-1Ca-0.5Zr alloy as a biomedical implant material. The results can be used as a reference for the biomedical material industry.

Effect of Surface Treatment and Aging on the Shear Bonding Strength of Interim Restoration Materials

@font-face { font-family: Calibri; }@font-face { font-family: BatMincho; }@font-face { font-family: Malgun Gothic; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 10pt; line-height: 115%; font-size: 11pt; font-family: Times New Roman; }div.Section1 { page: Section1; } Statement of Problem Interim restorations are required for extended periods as complex treatment is being established or to assess long-term prognosis of teeth. The reparability of interim restorations relies on adhesion of the repair material onto the parent restorative material. Purpose The purpose of this study was to investigate the shear bonding strength of bis-acryl composite resins compared to autopolymerizing polymethyl methacrylate (PMMA) under different surface treatments and environmental conditions. Material and Methods Eighty cylindrical specimens fabricated from PMMA and bis-acryl received one of the following of environmental treatments: no surface treatment, surface roughening with SiC paper, grinding with bur or chemical treatment. One group was stored in water for 24 h (37 °C, distilled water) and the other group was stored in coffee for 24 h (37 °C). Shear bond strength was determined by loading the specimens to failures with a 10 kN load cell and a 0.5 mm/min crosshead speed. The statistical significances were evaluated by Kruskal-Wallis one-way ANOVA . Every analysis was approved with 95% reliance. Results For PMMA stored in water, there was no statistical difference between different surface treatments. For PMMA stored in coffee, surface roughening treatment with SiC paper had the highest average bonding strength and was significantly better than no surface treatment or surface treatment with bur. For bis-acryl stored in water, surface roughening with SiC paper had the highest average bonding strength and was significantly better than no surface treatment. Surface treatment with bur was also significantly better than no surface treatment. For bis-acryl stored in coffee, the highest average bonding strength was for surface treated specimens with SiC and this was significantly better than surface treatment with bonding agent. Whether specimens were stored in water or coffee, PMMA was significantly better than bis-acryl in all surface treatment groups. Conclusions In all environmental conditions including no surface treatment, surface roughening with SiC paper, grinding with bur, or chemical treatment, and in all storage media, PMMA has better bonding strength compared to bis-acryl. For bis-acryl specimens, surface roughening with SiC paper improved bonding strength of the repair material to the parent material.

Influence of surface modified basalt fiber on strength of cinder lightweight aggregate concrete

In order to improve the bonding and bridging effect between volcanic slag lightweight aggregate concrete cement and basalt fiber, The basalt fiber was subjected to etching and roughening treatment by NaOH solution, and the surface of the basalt fiber was treated with a mixture of sodium silicate and micro-silica powder. The influence of modified basalt fiber on the strength of volcanic slag lightweight aggregate concrete was systematically studied. The experimental results show that the modified basalt fiber volcanic slag lightweight aggregate concrete has a flexural strength increased by 47%, the compressive strength is improved by 16% and the toughness is increased by 27% compared with that of the non-fiber.

Application of erosion-resistant fibers in the recovery of vegetation on steep slopes in the Loess Plateau of China

As the economy develops, infrastructure construction in the Loess Plateau of China often leads to the formation of exposed steep slopes over large areas. Exposed steep slopes will lead to severe soil erosion, which poses a threat to ecological security. In addition, the recovery of vegetation on steep slopes also faces significant difficulties. Therefore, research on the materials and techniques suitable for the recovery of vegetation on steep slopes is important for improving the ecological environment. In this study, an environmentally friendly substrate with wood fibers, High Performance-Flexible Growth Medium (HP-FGM), as the main component is used for spray seeding, and a biotic soil medium (BSM) and eight native plant species were selected to regrow vegetation on steep slopes with different aspects (semi-shady and semi-sunny, with gradients>50°). The resistance to scouring and erosion of the HP-FGM was analyzed via simulations and a spray seeding experiment. In addition, the effects of the HP-FGM on the soil moisture content (SMC), the soil nutrient content (SNC), the physical properties of the soil and the plant growth during the vegetation recovery process were also investigated. The results show that the HP-FGM could effectively reduce erosion on the slope surface. When combined with BSM and a slope surface roughening treatment, the HP-FGM significantly improved the SMC, the SNC and the physical properties of the soil. In addition, the cost was only approximately USD $5/m2. The results of this study show that the combination of the HP-FGM, BSM and the slope surface roughening treatment is economical and environmentally friendly and can achieve relatively good vegetation recovery; thus, it is worth popularizing and has good prospects for applications in regions where vegetation recovery on steep slopes is needed, such as the Loess Plateau of China.