TiO2 Research Articles

Postoperative sensitivity of composites using novel Bacillus subtilis nanofortified adhesives: a triple-blind study

Nanotechnologyis the art and science of dealing with nanoscale particles. This has transformed contemporary dental practices through myriad contributions to biomaterial science. Titanium dioxide nanoparticles procured from Bacillus subtilis, an eco-friendly and biogenic source, can significantly magnify the physiochemical attributes of dental materials. However, postoperative sensitivity is a major drawback of composite restorations. The incorporation of these nanoparticles into dental adhesives can greatly benefit clinical dentistry by resolving this issue. This trial aimed to evaluate the effectiveness of a novel titanium dioxide nanofortified adhesive on the postoperative sensitivity of composite restorations.MethodsThis triple-blind, parallel-group randomized controlled trial was conducted at the Department of Operative Dentistry and Endodontics, School of Dentistry, Islamabad, from May 15, 2023, to November 25, 2023. Participants (n = 60) with Class I and II primary carious lesions with a minimum cavity depth of 3–5 mm were randomly assigned to two groups (n = 30). After obtaining informed consent, the restorative procedure was accomplished using a minimally invasive approach and etch-and-rinse adhesive strategy. In group A, a nanofortified adhesive was used for composite restoration, whereas in group B, an adhesive without nanoparticles was used. Postoperative sensitivity was evaluated using the Visual Analog Scale (VAS) score at follow-up periods: of one day, one week, two weeks and one month. A Chi-square test was used to compare postoperative sensitivity between the two groups. The level of significance was set at p < 0.05.ResultsA noteworthy association was observed between sensitivity and the group variable at all four evaluation periods: after one day (p = 0.002), 1 week (p = 0.002), 2 weeks (p = 0.007) and one month. In conclusion, participants who underwent restorative intervention using titanium dioxide nanoreinforced adhesives reported a notable reduction in sensitivity at all time intervals. Hence, the occurrence and severity of postoperative sensitivity are significantly reduced using Bacillus subtilis-procured nanofortified adhesives as compared to conventional adhesives without nanoparticles.Trial registrationThis trial was retrospectively registered at ClinicalTrials.gov (ID: NCT06242184) on 03/02/2024. All procedures involving human participants were performed in conformance with this protocol.

Polyethersulfone ultrafiltration membranes co‐blended with amphiphilic polymers and nitrogen‐doped titanium dioxide nanoparticles for anti‐fouling and photocatalysis

Polyethersulfone ultrafiltration membranes co‐blended with amphiphilic polymers and nitrogen‐doped titanium dioxide nanoparticles for anti‐fouling and photocatalysis

Characterizations and optical discussions of thermally evaporated titanium dioxide thin films

Characterizations and optical discussions of thermally evaporated titanium dioxide thin films

Comparison of engineered nanoparticle transport in columns of three different lengths: Transport experiments and multi-observation point modeling

This study focuses on the effectiveness of commonly-used 15 cm column lengths for investigating nanoparticle transport in porous media. Experimental tests examined the transport and retention behaviors of two types of nanoparticles, graphene oxide (GO) and titanium dioxide (TiO2) nanoparticles, in saturated sand columns of different lengths (15, 30 and 45 cm), while considering key environmental factors like ionic strength (IS, 1–50 mM), flow rate (1–3 mL min−1), and grain size (150–850 μm). In the 15 cm columns, both GO and TiO2 transport decreased with higher IS and lower flow rate; grain size affected GO and TiO2 differently. Smaller grain size increased GO retention in the sand columns through straining, thus weakening GO mobility, whereas increased fluid shear force suppressed the ripening of TiO2, enhancing its migration. Similar environmental effects were noted in longer columns (30 and 45 cm), but fitted transport parameters (Smax and k) and predicted long-term mobility (Lmax) indicated that 15 cm columns might underestimate nanoparticle mobility. Blocking and ripening models based on single and multiple observation points to simulate nanoparticle transport and retention showed that predictions aligned well with experimental data. These results indicate that using combinations of columns of different lengths to achieve multiple observation points improves model prediction accuracy; in single-column experiments, the 45 cm and 30 cm columns respectively better predict the mobility range of GO and TiO2 compared to 15 cm columns.

Effect and mechanisms of surface treatment using nano titanium dioxide on the permeability of cementitious materials

Corrosive media typically penetrate the interior of cementitious materials through porous structures, causing corrosive damage. Strengthening the surface structure of the substrate is an effective method for enhancing the durability performance of such a material. This study investigates the effects of different concentrations of a nano titanium dioxide suspension (NTS) used for the surface treatment of cement specimens after 24 h of molding and the influence of this treatment on the impermeability of the substrate surface. The results indicate that at 28 d of hydration, water absorption by the 1 % NTS-treated specimens decreases by 45 %, and the resistance to chloride-ion penetration increases by 32.7 % with respect to that of the control group. Furthermore, results of the microscopic tests indicate that when NTS surface treatment is conducted on hardened cementitious materials, NTS provides nucleation sites to enhance the degree of cement hydration, fill minuscule voids, promote the dispersed growth of hydration products, optimize the surface pore structure, and increase the density of the microstructure, thereby improving the impermeability of the substrate surface. This study is expected to provide innovative ideas for the future utilization of nanomaterials for strengthening surface structures and enhancing the durability performances of cementitious materials.

Hierarchical Branched TiO2 Photo/Photoelectrocatalyst with Directed Charge Transfer for Efficient Hydrogen Production from Seawater.

The directed electron transport channel design in semiconductors, which could promote charge utilization, is attractive but rarely reported. Hierarchical branched titanium dioxide (HB-TiO2), possessing a charge cascade transfer channel, was constructed by assembling titanium-defected TiO2 nanobranches on oxygen-defected TiO2 nanobelts. The interfacial Ti/O vacancies have been detected by X-ray photoelectron and electron paramagnetic resonance spectroscopies, and the vacancies act as the "bridge" of photogenerated carrier transport. This structure maintained high photoactivity in H2 production in different mass fractions of NaCl solutions. The photocurrent density of the HB-TiO2 photoanode in natural seawater is 3.9, 2.1, and 2.6 times that of oxygen-defected TiO2 nanobelts, titanium-defected TiO2 nanobranches, and their mixture, respectively. Besides, the charge transport mechanism from the inner lattice to the TiO2 surface is proposed.

Characterization of Nano-kaolin and its enhancement of the mechanical and corrosion resistance of epoxy coatings

This study compares the effects of varying concentrations of nano-kaolin and titanium dioxide on the mechanical and corrosion resistance of epoxy coatings. Characterization techniques such as TEM, XRD, Raman, FTIR, XPS, and AFM revealed surface features of nano-kaolin: the particle size reached the nanoscale, the XRD diffraction peak at 2θ = 25.3° disappeared, Raman peaks broadened with decreased intensity, and a blue shift occurred in the FTIR spectra for various functional groups. Compared to pure epoxy coatings, the composite epoxy coating with 10 wt% nano-kaolin showed an 83.87 % increase in adhesion, an 81.82 % improvement in impact resistance, and a 61.42 % reduction in friction coefficient; while a 20 wt% titanium dioxide composite coating showed a 74.19 % increase in adhesion, a 75.76 % improvement in impact resistance, and a 46.9 % reduction in friction coefficient. Electrochemical tests indicated that a composite coating with 10 wt% nano-kaolin, after soaking in 3.5 wt% NaCl solution for 960 hours, achieved a corrosion efficiency of 98.87 % and an impedance modulus of 108.8Ω.cm2, which was three orders of magnitude higher than that of pure epoxy resin, increasing corrosion resistance by 57.14 %; whereas a 20 wt% titanium dioxide composite coating reached a corrosion efficiency of 89.29 % and an impedance modulus of 106.6Ω.cm2 after the same conditions, increasing corrosion resistance by 17.86 % compared to the pure epoxy resin. The composite coating with 10 wt% nano-kaolin exhibited superior mechanical and corrosion resistance, outperforming the 20 wt% titanium dioxide coating. Mechanical and corrosion mechanisms suggest that the uniformly dispersed nano-kaolin inhibits interactions between epoxy resin molecules and carries the external load, thereby enhancing intermolecular cohesion. Improved adhesion and impact resistance indirectly extend the coating's lifespan by prolonging the path of corrosion media through the coating to the substrate. The novel coating modification method proposed in this study effectively replaces titanium dioxide and enhances the coating's mechanical and corrosion resistance, offering a new solution for corrosion prevention in metal materials.

Photo‐Curable Stretchable High‐k Polymer/TiO2 Nanosheet Hybrid Dielectrics for Field‐Effect Transistors

Elastomeric polymer materials are of interest due to their stretchability, low‐temperature processing, and scalability. In addition, the incorporation of 2D materials can further enhance the dielectric properties and capacitance of elastic polymer materials, thereby reducing the driving voltage and energy consumption. In this study, titanium dioxide (TiO2) nanosheets are cross‐linked with nitrile butadiene rubber using thiol‐ene click chemistry, which leads to the preparation of nanocomposite dielectric films with stretchability and high dielectric constant. Furthermore, by controlling the doping amount of the nanosheets, it is observed that the capacitance of the nanocomposite films increases from 25.61 to 684.67 nF cm−2, and the dielectric constant increases from 14.96 to 161.98. Finally, the stretchable nanocomposite films exhibit good insulating properties even at 50% strain. In this study, insight is provided into the potential of in situ cross‐linking between elastic polymer materials and 2D materials to produce high‐k dielectric materials with both stretchability and high insulating properties.

Green synthesis of TiO2@g-C3N4 nanocomposites for the photocatalytic degradation of pesticides and toxic organics present in water and wastewater

To address the environmental challenges caused by toxic organics in aquatic systems, photocatalytic degradation is a promising option. This study investigates the green synthesis of TiO2@g-C3N4 nanocomposites by coupling Titanium dioxide (TiO2) and graphitic carbon nitride (g-C3N4) in different mass ratios through solvothermal technique due to their photocatalytic properties. Leaf extract from the Ziziphus jujube plant was utilized as a green template making the synthesis environmentally friendly, utilizing renewable resources, and employing facile and cost-effective methods. The nanocomposites were characterized using various analytical techniques including UV–Vis Diffuse reflectance spectroscopy (UV–Vis DRS), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS) to analyze the structural and morphological properties. The wavelength ranged from 385 to 454 nm and band gap energies ranged from 3.22 to 2.73 eV for the synthesized materials. The pure green TiO2 showed the highest band gap energy while pure g-C3N4 showed the lowest band gap energy among the synthesized materials. The photocatalytic activity of the synthesized nanocomposites was evaluated through the degradation of Bisphenol A and Malathion pesticide under UV light irradiation. The results indicated 71 % degradation of Bisphenol A with the 50 % TiO2@g-C3N4 nanocomposites exhibiting 1.422 x 10-2 min−1 rate constant and 74 % degradation of Malathion degraded over 20 % TiO2@g-C3N4 which depicted rate kinetics of 1.022 x 10-2 min−1. Moreover, both showcased higher performance than the individual TiO2 and g-C3N4 nanostructured materials.

A screening method for detection of TiO2 in food based on Raman spectroscopy and its applicability in a regulatory context

Starting from August 7, 2022, with the publication of the European Regulation EU 2022/63, the European Commission has prohibited the use of titanium dioxide (TiO2) (E 171) as a food additive within the European Union (EU). As the food industry has the obligation to adapt the formulation of their products accordingly, it is now crucial for EU member states' competent authorities and official control laboratories to have adequate analytical methods to ensure compliance with this new regulation. The existing literature predominantly focuses on quantitatively determining the elemental titanium (Ti) concentration by ICP-based techniques after complete digestion of the analyte and the food matrix. Compared to this approach, Raman spectroscopy would offer the possibility of a more rapid albeit qualitative screening by identifying the insoluble fraction of titanium dioxide after removing the food matrix. It is also important to note that compliance with the EU ban requires determining the presence of TiO2 in particulate form, an information that Raman spectroscopy can easily deliver. As a further advantage, an analytical approach based on Raman spectroscopy eliminates the need for using particularly harmful acids, which are necessary for the complete digestion of TiO2, when ICP-based analytical methods are employed. In the present study, the aim was first to gather information on the commonly occurring total Ti levels in food and, second, to discuss the potential of a newly developed Raman procedure based on TiO2 extraction by mild acid digestion of the food product as a rapid, safer albeit qualitative screening method. To evaluate the effectiveness of the Raman procedure in verifying compliance with the European Regulation, the qualitative results obtained using a macro-Raman instrument were compared with those obtained through ICP-based techniques on the same food samples, used as benchmark. In total 22 food-samples belonging to 6 different food categories were analysed. The sampling was conducted in the Italian, Belgian, and French markets both before and after the EU ban on E 171 entered into force. The limit of detection, qualitatively established, was 50 mg kg−1, which effectively encompasses the majority of food items containing E 171, as supported by the extensive literature review. The results obtained with the Raman screening method were found to align well with information reported on product labels and benchmark quantitative data.

A novel kind of hollow SiO2@g-C3N4@TiO2 microspheres for rapid removal of dyes and antibiotics in water under sunlight

In this paper, using PVP-modified polystyrene microspheres as template, tetrabutyl titanate (TEOT), tetraethyl orthosilicate (TEOS) and melamine as precursor, we developed a facile one-pot two-step method to preparing a novel kind of mesoporous hollow SiO2@TiO2@g-C3N4 ternary composite microspheres with plush surface, in which highly active black titanium dioxide (TiO2) was formed by simple calcination without further chemical reduction treatment. The structure and morphology of the composite microspheres were detailed characterized for understanding the formation mechanism. Research results indicated that the hollow SiO2 microspheres can promote the formation of oxygen vacancies in TiO2, and the ternary combination narrowed the bandgap width of the black hollow composite microspheres to 1.43 eV, thus endowing it with excellent broad-spectrum catalytic performance for rapid photo-degradation of persistent organic pollutants (POPs) such as dyes and antibiotics in water under sunlight. The removal rates of dyes reached more than 70 %, as well as that of antibiotics more than 50 % within one hour. Finally, a plausible catalytic degradation mechanism was discussed.

The novel α-TiO2@g-C3N4 heterostructure for ultra rapid ionic pumping and effective capacitive deionization

Anatase titanium dioxide (α-TiO2) has been widely identified as an efficient electrode material for capacitive deionization (CDI). However, this material usually suffers from limited exposure of active sites, poor electrical conductivity and significant obstacles in ion movement due to its tendency to severely aggregate during its preparation. A novel approach to fabricate α-TiO2@g-C3N4 composite materials was proposed in this work. In detail, the 2D material g-C3N4 serves as a high-speed electron-conducting scaffold, allowing uniform loading of nanoscale α-TiO2 and exposing abundant active sites. Furthermore, g-C3N4 facilitates electron transport to nanoscale α-TiO2, enhancing charge transfer and activating previously underutilized electrochemical centers. As a result, α-TiO2@g-C3N4 composites were synthesized for the first time. Through these improvements, the prepared α-TiO2@g-C3N4 exhibits excellent desalination performance, with a high degree of efficiency in water purification. It shows an improved salt adsorption capacity (SAC) of 50.4 mg g-1 and a salt adsorption rate (SAR) of 2.7 mg g-1 min−1 in a 1.2 V, 1 mm electrode spacing, and 500 mg L-1 NaCl solution. This outstanding CDI performance surpasses most recently reported electrode materials. More importantly, this electrode showed remarkable removal efficiencies for various heavy metal ions (Ni2+, Cr3+, Cu2+, Pb2+, Fe3+ and Cd2+), indicating its significant potential for wastewater purification. The superior CDI performance of the α-TiO2@g-C3N4 composite material endows it with practical application in future.

The Effect of Green Tea Extract on Pulmonary Inflammation in Nanoparticles-Exposed Mice.

Titanium dioxide nanoparticles (TiO2 NPs) are air pollutants that exacerbate chronic respiratory diseases such as asthma and Chronic Obstructive Pulmonary Disease (COPD) However, little is known about the mechanism underlying the antipollutant effects of green tea extract (GTE). This study evaluates the efficacy and mechanism of GTE on lung inflammation and fibrosis in mice exposed to TiO2 NPs. The TiO2 NPs model is induced by having mice inhale TiO2 NPs, while controls receive an equivalent volume of saline. Treatment with oral GTE is initiated after TiO2 NPs inhalation and is given once daily for 4 weeks. Airway resistance and pulmonary inflammation are increased in mice exposed to TiO2 NPs. GTE treatment reduces the airway inflammation and airway resistance, and attenuates the pathological changes including lung fibrosis compared to the mice exposed to TiO2 NPs. With GTE, there are no significant increases in cytokines and immunoglobulin E (IgE) in mice exposed to TiO2 NPs. GTE inhibits matrix metalloproteinases (MMPs) and apoptotic factors induced by TiO2 NPs exposure, and these protective effects of GTE are closely related to the mitogen-activated protein kinase (MAPK) signaling pathway. GTE modulates pulmonary inflammation in mice exposed to air pollutants, suggesting that GTE may be beneficial in respiratory diseases exacerbated by such pollutants.

Effects of graphene oxide and silane‐grafted graphene oxide on chitosan packaging nanocomposite films for bread preservation

AbstractThis study aims to investigate the dual effects of (3‐aminopropyl)triethoxysilane (APTES)‐grafted‐GO (A‐g‐GO), and titanium dioxide (TiO2) on the novel chitosan (CS) packaging nanocomposite films developed via the solution‐casting method. The chemical properties of GO and A‐g‐GO were assessed using FTIR and XRD. Subsequently, the chemical, structural, and physical attributes of all chitosan packaging nanocomposite films were analyzed through FTIR, XRD, TGA, DSC, AFM, water contact angle analysis, and food packaging tests. Successful silanization of GO by APTES was first confirmed. The highest surface roughness value was observed in the CS/A‐g‐GO/TiO2 film (16.574 nm) compared to pristine CS and other nanocomposite films. Incorporating GO into the CS matrix improved its thermal stability, suggesting robust bonding between GO and the polymer matrix. The addition of A‐g‐GO slightly decreased the contact angle value (107.7° for CS/A‐g‐GO), whereas TiO2 increased contact angles (117.3° for CS/GO/TiO2 and 119.4° for CS/A‐g‐GO/TiO2), suggesting a more hydrophilic structure with GO and A‐g‐GO and a more hydrophobic structure with TiO2. Bread samples showed no structural distortion over 40 days. Therefore, the dual impacts of A‐g‐GO and TiO2 on the pristine CS film imply that the resulting CS/A‐g‐GO/TiO2 film exhibits potential as an exceptionally efficient packaging material for prolonging the freshness of bread.

Investigation on TiO2 spin-coated thin films effect on the optoelectronic properties of stain-etched porous silicon for solar cell applications

This article aims to improve the opto-electronic properties of porous silicon (PS) to integrate it as an anti-reflecting coating in solar cell applications. The enhancement of its properties is achieved through the passivation of its surface by titanium dioxide (TiO2). Samples of porous silicon were elaborated using stain etching technique, then treated with the metal oxide using spin-coating technique. The film thickness was varied to study the thickness effect on the properties of the TiO2/PS structure. Morphological study has shown that most pores were covered with TiO2 structures, resulting in an overall change in the surface morphology. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis has confirmed the TiO2 deposition on PS surface. The passivation of PS with TiO2 had more interesting results, especially in the case of PS passivated with three layers of TiO2, which suggests a good coverage of the surface of PS, results confirmed by optical study and minority carrier lifetime measurement. Moreover, a simulation was also carried out using PC1D. The optoelectronic results of the synthesized TiO2/PS samples were applied on a built-in model of a commercialized silicon-based solar cell. The efficiency increased from 11% for an untreated silicon solar to 15.8% for the cell modeled with 3 layers of TiO2 deposited on PS.

Green synthesized Waste‐Derived Anatase form of TiO2 Nanoparticles from Hordeum vulgare L. (Barley): A Multidisciplinary Approach Connecting Biology, Environment, and Agriculture

AbstractBiological methods for creating nanoparticles utilizing plant‐based extracts have generated considerable interest due to their desirable ecological characteristics when compared to chemical methods. In this, TiO2 NPs were synthesized from the waste of the Hordeum vulgare L. We employed various methods for characterizing our sample, including Ultraviolet‐visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction, Scanning electron microscopy, Energy dispersive X‐ray spectroscopy, thermogravimetric analysis, AFM, Dynamic light scattering and Zeta‐potential to confirm the TiO2 NPs (Titanium dioxide Nanoparticles) synthesis followed by biological applications such as anti‐microbial, and anti‐oxidant assays to confirm TiO2 NPs biological properties. The photocatalytic activity of the TiO2 nanoparticles was also studied followed by a full factorial method to understand the consequences of time, pH, and concentration on the dye degradation. Apart from this, the synthesized nanoparticles were also used to check the agricultural efficacy on Phaseolus vulgaris plant seed, where it was seen that the TiO2 nanoparticles not only enhanced the growth of the plant at lower concentrations but also enhanced the photosynthetic activity and chlorophyll, phenol and flavonoid content of it when compared to higher concentration and control. The molecular aspects (DNA) were also analyzed by gel electrophoresis to check the effect of TiO2 nanoparticles on the DNA of plants at different concentrations. Our study focuses on making the best use of the waste of Hordeum vulgare L. to synthesize biogenic TiO2 nanoparticles that can prove themselves to be one of the significant options for the industrial, agricultural, and biological world.

Coating of Refractory Surfaces with Fine TiO2 Particles via Gas-Dynamic Cold Spraying

Refractory materials are used worldwide in process equipment. However, gaseous and liquid process products penetrate the surface layer and deep into the volume of refractories, destroying rather expensive constructions that are complicated to repair. To address this challenge, there is a need to develop protective coatings for refractory materials that can limit the penetration of working media and extend their operational lifespan. In this work, the application of gas-dynamic cold spraying (CGDS) to produce a coating on the refractory materials using fine titanium dioxide (TiO2) particles is explored. These particles are accelerated within a nitrogen flow, passing through a Laval nozzle, and then sprayed onto a fireclay surface. The mechanisms of particle deposition and layer formation on porous surfaces through experiments and numerical simulations were investigated. The geometry of a typical refractory pore was determined, which was then incorporated into computational fluid dynamics (CFD) simulations to model the cold spraying process of porous substrates. As a result, the influence of the particle size on its velocity and angle of penetration into pores was established. Experimental findings demonstrate the effective closure of pores and the formation of a particle layer on the refractory surface. Furthermore, the nanoindentation tests for the refractory samples showcase capabilities for checking coating thickness for porous materials.

Tunable distributed Bragg reflector developed by magnetron sputtering to improve the power conversion efficiency of transparent IR cells for solar energy harvesting applications

Transparent organic photovoltaic (TOPV) cells integrated into windows are key to reducing the carbon dioxide emissions associated with the building sector. However, TOPV cells that reach a compromise between efficiency and transparency must still be developed. In addition, to implement this technology in glass production companies, the materials and processes used in TOPV cell development must be compatible with producing these devices on an industrial scale. Here, an infrared (IR) cell combining a PC60BM-based active material, ITO/ZnO as the back transparent electrode, PEDOT:PSS and ITO or Ag as the top transparent electrode, and a DBR as an antireflective coating was developed and applied on 625 mm2 glass samples. The structure of the DBR based on titanium dioxide (TiO2) and silicon dioxide (SiO2) monolayers was adjusted to the IR cell absorption spectra to reach a power conversion efficiency (PCE) of 5 and 4.3, and an average visible transmission (AVT) of 41 % and 51 % for ITO and Ag top electrodes, respectively. The manufacturing route of these devices involved commercial polymers and coatings that can be deposited by technologies already applied in the glass industry, such as magnetron sputtering or thermal evaporation. Therefore, the IR cells developed here showed a good compromise between efficiency, transparency, and large-scale production manufacturability.

Effect of PFDTS/TiO2 Coating on Microstructure and Wetting Behavior of Phosphogypsum.

Phosphogypsum (PG) constitutes a form of solid byproduct emanating from the manufacturing process of wet-process phosphoric acid. The fabrication of one metric ton of wet-process phosphoric acid entails the generation of approximately five tons of phosphogypsum, a highly prolific and economically viable waste stream. If we can effectively solve the problem of poor hydrophobicity of phosphogypsum, it is possible to replace cement and other traditional cementitious materials. In this way, we can not only improve the utilization rate of phosphogypsum but also obtain significant economic and environmental benefits. In the present investigation, hydrophobic surface coatings were synthesized and applied onto the surface of α-hemihydrate phosphogypsum (α-HPG) utilizing sol-gel processing and impregnation techniques. After hydroxylating α-HPG with alkaline solution (OH-α-HPG), titanium dioxide nanoparticles (TiO2) hybridized with perfluorodecyltriethoxysilane (PFDTS) were grafted on its surface. The assessment of the hydrophobic properties of the coatings was conducted through water contact angle measurements, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) analyses. The contact angle remained above 124.2° after strong acidic and alkaline immersion and 50 tape adhesion experiments with good chemical stability and durability, and the mechanism of surface hydrophobicity modification was discussed. The experimental outcomes demonstrated a notable increase in the hydroxyl group concentration on the α-HPG surface following hydroxylation, significantly enhancing the attachment rate of PFDTS and TiO2 onto the HPG surface. PFDTS and TiO2 can undergo chemical interaction with hydroxyl groups, facilitating their robust adsorption onto the surface of OH-α-HPG through chemisorption mechanisms. After bonding the OH-α-HPG surface with PFDTS and TiO2 via hydrogen bonding, the otherwise hydrophilic α-HPG surface acquired excellent hydrophobicity (OH-α-HPG-PT, contact angle (CA) = 146.7°). The surface modification of α-HPG through hydroxylation and hydrophobicity enhancement significantly augmented the compatibility and interfacial interplay between α-HPG and PT. This research successfully enhanced the hydrophobic properties of α-HPG, profoundly showcasing its immense potential within the construction industry and the realm of comprehensive solid waste utilization.

Evaluation of Tensile Bond Strength of Nanoparticle Reinforced Soft Liner Materials: A Pilot Study

OBJECTIVE: The aim of this study is to evaluate the tensile bond strength between polymethyl methacrylate (PMMA) surfaces and autopolymerized silicon-based soft lining materials with 1% w/w Titanium dioxide (TiO2) and Hydroxyapatite (HA) nanoparticles added. MATERIALS AND METHODS: For the tensile test, 60 pieces of acrylic (Meliodent, Bayer Dental, Newbury, England) samples of 30 × 10 × 10 mm3 dimensions were prepared using metal molds. Acrylic surfaces were sanded with silicon carbide sandpapers of 500, 1000, 1500, and 2000 grids to ensure standardization. After the samples were placed back in the metal mold, adhesive (Detax, Germany) was applied to the surfaces that would come into contact with the soft lining. Soft lining materials (Mollosil, Detax, Ettlingen, Germany) to which 1% by weight TiO2 and 1% HA nanoparticles were added were polymerized by placing them between two acrylic blocks. For the tensile test, a total of 30 samples were obtained, with 10 samples in each group (n=10). The specimens were placed on the holder end of the universal test device and force was applied until failure occurred. RESULTS: The tensile bond strength (0,86 ± 0,21 MPa) in the TiO2 nanoparticle-added group was found to be significantly higher than the control group (0,65 ± 0,14 MPa) (p&amp;lt;0.05). There is no significant difference between the control group and the HA nanoparticle-added group (0.65 ± 0.1 MPa) (p˃0.05). CONCLUSION: It was observed that the addition of nanoparticles increased the tensile strength. However, further studies are needed to evaluate the effect of nanoparticle addition on other mechanical and physical properties of soft liners.