title: Targeted functionalization of nanoparticle thin films via capillary condensation.
abstract: Capillary condensation, an often undesired natural phenomenon in nanoporous materials, was used advantageously as a universal functionalization strategy in nanoparticle thin films assembled layer-by-layer. Judicious choice of nanoparticle (and therefore pore) size allowed targeted capillary condensation of chemical vapors of both hydrophilic and hydrophobic molecules across film thickness. Heterostructured thin films with modulated refractive index profiles produced in this manner exhibited broadband antireflection properties with an average reflectance over the visible region of the spectrum of only 0.4%. Capillary condensation was also used to modify surface chemistry and surface energy. Photosensitive capillary-condensates were UV-cross-linked in situ. Undesired adventitious condensation of humidity could be avoided by condensation of hydrophobic materials such as poly(dimethyl siloxane).
authors.affiliation: Department of Chemical Engineering, Center for Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Zekeriyya
authors.initials: Z
authors.lastname: Gemici
authors.forename: Patrick I
authors.initials: PI
authors.lastname: Schwachulla
authors.forename: Erik H
authors.initials: EH
authors.lastname: Williamson
authors.forename: Michael F
authors.initials: MF
authors.lastname: Rubner
authors.forename: Robert E
authors.initials: RE
authors.lastname: Cohen
mesh_terms: D002621:Chemistry / Q000379:methods; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D010777:Photochemistry / Q000379:methods; D010825:Physics / Q000379:methods; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D004129:Dimethylpolysiloxanes; D011109:Polymethacrylic Acids; D012997:Solvents; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C013830:baysilon