Transparent and anti-fogging AlPO_(4)-5 films constructed by oblique oriented nano-flake crystals

In the present work,transparent and anti-fogging AlPO_(4)-5 films were prepared on glass substrates using a novel developed process.The process entails a simple in-situ sol–gel followed by vapor phase transport.The in-situ sol–gel process was implemented by coating the precursor sols for the synthesis of AlPO4-5 on the glass substrates successively using the spin-coating method.The films and powders scribed from the films were characterized by X-Ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),scanning electron microscope(SEM),atomic force microscope(AFM),X-ray photoelectron spectroscopy and transmission electron microscope(TEM).The unique films were composed of oblique oriented nanoflake AlPO_(4)-5 crystals with the thickness of about 20 nm.The formation of nano-flake crystals can be ascribed to the high concentration of the precursors,resulting in the formation of a supersaturation system.The obtained films showed high antifogging performance due to the superhydrophilicity with a water contact angle of lower than 1.0°.The silicone oil contact angle was also low about 8.2°.In addition,heteroatom-substituted AlPO_(4)-5 films showing different colors can be obtained easily by simply adding transition metal ions in the phosphate acid solution during the preparation that can extend the application of the method for different coating demand.

Fabrication of New Transparent and Hydrophilic Hybrid Anti-fog Coating from Silane Coupler Modified by Polyethylene Glycols

A new and effective organic-inorganic hybrid hydrophilic anti-fog coating was proposed and prepared. As is well-known, the presence of an inorganic component typically decreases the hydrophilicity and transparency of the coating. To solve this problem, we used polyethylene glycol with two different molecular weights to modify the si- lane coupling agent and mixed it with hydrophilic copolymer to form coating formulas. We coated these formulas on polycarbonate（PC） substrates to measure the anti-fogging properties via contact angle and anti-fogging tests, com- pared their transparency properties using UV-Vis spectra and evaluated the hardness using a pencil hardness tester. The results demonstrate that the molecular weight of PEG has a strong influence on the properties of the anti-fog coatings. After the corresponding optimization, we manufactured an excellent anti-fog coating. In addition to good adhesion and hardness, the coating also exhibited excellent mechanical properties, optical transparency and perfect anti-fogging performance.

A TiO_(2)nanotubes film with excellent antireflective and near-perfect self-cleaning performances

SiO_(2)/TiO_(2)composite films have been frequently used to realize the functions of self-cleaning and antireflection.Increasing the TiO_(2)volume ratio in SiO_(2)/TiO_(2)composite film is beneficial to enhance the self-cleaning effect,while high TiO_(2)content leads to a strong Rayleigh scattering and depresses the antireflective performance,resulting in a bottleneck problem for the dual-functional application.Here,we have achieved a high-quality TiO_(2)nanotubes film with excellent antireflective and near-perfect selfcleaning performances.Ultrasound assisted pickling method has been developed to effectively prepare the well-dispersed protonated titanate nanotubes colloid.After spin-coating and annealing treatment,glass substrate coated with double-side TiO_(2)nanotubes film has a peak transmittance of 99.2%and average transmittance of 97.4%at 400-800 nm.Ultra-high porosity of TiO_(2)nanotubes film(80%)and ultra-fine size of TiO_(2)nanotubes(8.6 nm in outer diameter)lead to excellent antireflective performance.With high UV absorptivity(80%at 254 nm)and formal quantum efficiency of stearic acid(10.9×10^(-3)),TiO_(2)nanotubes film shows near-perfect self-cleaning performance.A persistent anti-fogging ability is also presented.This study demonstrates the feasibility to fabricate pure TiO_(2)antireflective coating for glass substrate,extends application field of the classic TiO_(2)nanotubes,and sheds lights on the practical applications of high-powered TiO_(2)nanotube-based multi-functional films.

Broadband Antireflective Superhydrophilic Thin Films with Outstanding Mechanical Stability on Glass Substrates

A facile approach was developed to fabricate visible/near-infrared antireflective(AR),superhydrophilic and anti-fogging thin films on glass substrates.Glass substrate was first etched by H_(2)SiF_(6)-based vapor and then dip-coated sequentially in a base-catalyzed 20 nm SiO_(2)nanoparticles sol and an acid-catalyzed SiO_(2)sol.After an-nealing,the prepared thin film(named E/BSiO_(2)/ASiO_(2))not only showed good optical and wetting properties,but also exhibited excellent mechanical properties.The thin film has enhanced transmittance in the spectral range of UV to near-infrared.The maximum transmittance of E/BSiO_(2)/ASiO_(2)thin film coated glass substrate is 98.4%in 400-1200 nm and 96.1%in 1200-2500 nm,respectively.Comparing with blank glass substrate,the average transmittance increases by 5%in the wavelength range of 300-2500 nm.Meanwhile,the film showed good anti-fogging performance.SEM and AFM were employed to characterize the morphology of the thin film.The pre-pared thin film has potential application in various areas,like solar cells,windowpanes and eyeglasses,and may also find applications in membrane-based separation,selective catalysis and sensors.