Preparation Of Superhydrophobic Coating On Wood Surface By Electron Beam Radiation And Its Properties

Construction of superhydrophobic coating on the surface of the wood can not only effectively prevent the entry of moisture,avoid deformation,cracking,discoloration,and rot caused by moisture absorption and water absorption,but also endow the wood surface with many new functions(e.g.,self-cleaning,anti-corrosive,and anti-fouling).Although many strategies have been proved to construct superhydrophobic surfaces,most of them require a multi-step,time-consuming,and expensive preparation procedure.Additionally,the mechanical wear-resistance and chemical durability of the superhydrophobic coating on the wood surface are still the key factors hindering the large-scale application of superhydrophobic wood.To obtain superhydrophobic wood with prominent properties such as abrasion resistance and chemical durability.In this study,tetrabutyl titanate(TBOT)was used as a precursor to construct a TiO2 micro/nano binary roughness structure on the wood surface through simple sol-gel technology.Hydroxy-terminated polydimethylsiloxane(PDMS)was modified on the wood surface to reduce surface energy.The monomerγ-methacryloyloxypropyltrimethoxysilane(MAPS)was added to participate in the polymerization reaction,and then free radical polymerization was initiated by EB radiation to cure the superhydrophobic coating on the wood surface.The main contents are as follows:(1)Taking poplar as the research object,the optimum preparation conditions for preparing the superhydrophobic coating on the wood surface through EB radiation were investigated;the micro structure and functional groups of the treated poplar surface were analyzed using Scanning electron microscopy(SEM)and Fourier-transform infrared spectroscopy(FT-IR).The results showed that the nano TiO2 particles were successfully deposited on the surface of poplar wood(～500 nm in diameter).The optimized parameters for preparing the superhydrophobic coating on the wood surface were 0.4%volume fraction of TBOT,0.5%volume fraction of PDMS,0.2%volume fraction of MAPS,and the total absorbed dose of EB was 5 kGy.The as-prepared wood exhibited a water contact angle of approximately 166.160 and the rolling angle is～1.9°.(2)To explore the effect of EB radiation on the superhydrophobic coating on the surface of poplar and the basic properties of superhydrophobic poplar.Under the optimal process parameters,the prepared hydrophobic poplar and EB radiation poplar were characterized by SEM,X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).A series of experiments were performed to investigate the hydrophobicity and self-cleaning properties,thermal stability,chemical stability,UV resistance,and aging properties of the superhydrophobic poplar prepared through EB radiation.The test results reveal the influence mechanism of EB radiation on the preparation of superhydrophobic poplar.The experimental results showed that the superhydrophobic coating can effectively postpone the thermal degradation rate of poplar;meanwhile,the obtained superhydrophobic poplar can resist water droplets with a temperature range of 10～60℃ and droplets with a pH value of 2-12.Superhydrophobic poplar still maintained superhydrophobicity even in the solution of pH=2,pH=12 for 1 h,and 2 h in ethanol,acetone,cyclohexane,and N,N-dimethylformamide(DMF).In addition,the superhydrophobicity of the superhydrophobic poplar surface showed no significant decrease after 90 days in the natural environment.When the superhydrophobic poplar was exposed to UV light for 18 days,the target surface showed no obvious discoloration and maintained its superhydrophobicity.(3)To investigate the general applicability of EB radiation technology,superhydrophobic wood was prepared on different species of wood.In addition,commercially available superhydrophobic wood coatings with excellent performance were selected for hydrophobic treatment of the wood surfaces of these three species.The properties of the superhydrophobic wood prepared through EB radiation and the superhydrophobic coating prepared by coating were compared in terms of hydrophobicity,self-cleaning property,abrasion resistance,ultrasonic cleaning resistance,acid and alkali resistance,etc.The results showed that the superhydrophobic wood prepared through EB radiation has universality,the corresponding contact angles were all>164° and the above properties were better than those of the superhydrophobic wood prepared by coating.