Self-Cleaning Antireflective Coatings Assembled from Peculiar Mesoporous Silica Nanoparticles

Abstract

Novel mesoporous silica nanoparticles of peculiar shapes were synthesized, from which hierarchically porous silica coatings were fabricated on glass substrates via layer-by-layer (LbL) assembly, followed by calcination. These porous silica coatings were highly transparent and superhydrophilic. The maximum transmittance reached as high as 94%, whereas that of the glass substrate is 91%. The time for a droplet to spread lower than 5 degrees decreased to as short as 0.25 s. After the coating surface was treated with a low surface energy material, the surface became superhydrophobic (water contract angle >150 degrees) with a very low sliding angle of <1 degree. Compared with MCM-41-type mesoporous silica nanoparticles, the coatings fabricated using the novel mesoporous silica nanoparticles possess much better self-cleaning property. We used scanning (SEM) and transmission (TEM) electron microscopy to observe the morphology and structure of nanoparticles and surfaces. Transmission spectra and their change with time were characterized by UV-vis spectrophotometer. We studied the surface wettability by a contact angle/interface system. The influence of mesopores on the transmittance and wetting properties of coatings was discussed on the basis of experimental observations.

Core‐Cone Structured Monodispersed Mesoporous Silica Nanoparticles with Ultra‐large Cavity for Protein Delivery

“…Recently, MSNs with radial pore structures [12][13][14][15][16][17][18][19][20] have been synthesized using oil and water systems with promising applications such as siRNA (≈14 KDa) delivery. [ 17 ] MSNs with fi brous, [ 13 ] dendritic, [ 15,16,20 ] radial wrinkle, [ 14 ] or chrysanthemum-like radial pore structures [ 19 ] were prepared through various synthesis protocols and explained by different mechanisms.…”

Detailed analysis and formation mechanism of superhydrophobic antireflective coatings with adjustable refractive index from trimethylsilanized silica nanoparticles

“…At this reaction stage, some SNPs begin to connect together, which confirms the enlargement of SNPs caused by the aggregation of SNPs. With the increase in the reaction time, the aggregation between SNPs is so serious that it is very difficult to find any individual SNP, which are attractive for the construction of rough and stable surfaces [25].…”

Facile Fabrication of Hollow Mesoporous Silica Nanospheres for Superhydrophilic and Visible/Near‐IR Antireflection Coatings

“…Such morphologies might significantly influence the transmittance and wetting property of the coatings. [16,19,23] Optical performance of coatings: Figure 6a and b show the transmission and reflection spectra of control slide glass and slide glasses coated with one, two, and four cycles of PDDA/ S2 MSNs, respectively, followed by calcination. Clearly, the slide glasses deposited with S2 particulate coating show significantly enhanced transmittance and AR properties compared with control slide glass.…”

“…The water molecules in the air will adsorb in the porous silica coatings due to capillary condensation phenomenon, [11,13,16,[40][41][42] thus increasing the refractive index and then reducing the transmittance of coatings. Figure S10 in the Supporting Information shows UV/Vis transmission spectra of slide glass coated with one cycle of PDDA/S2 after being stored in air (RT: 20-30 8C; RH: 20-40 %) for 0 h (curve 1) and one week (curve 2), and after being washed with a large amount of water and then simply dried by N 2 flow (curve 3).…”