Hydrophobic monolithic aerogels by nanocasting polystyrene on amine-modified silica

被引:107
作者
Ilhan, U. Faysal
Fabrizio, Eve F.
McCorkle, Linda
Scheiman, Daniel A.
Dass, Amala
Palczer, Anna
Meador, MaryAnn B.
Johnston, James C.
Leventis, Nicholas
机构
[1] NASA, Mat & Struct Div, Glenn Res Ctr, Cleveland, OH 44135 USA
[2] Ohio Aerosp Inst, Cleveland, OH 44142 USA
[3] Univ Missouri, Dept Chem, Rolla, MO 65409 USA
关键词
D O I
10.1039/b604323b
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
We describe a three-dimensional core-shell structure where the core is the assembly of nanoparticles that comprises the skeletal framework of a typical silica aerogel, and the shell is polystyrene. Specifically, the mesoporous surfaces of silica were first modified with amines by co-gelation of tetramethylorthosilicate (TMOS) and 3-aminopropyltriethoxysilane (APTES). Next, styrene moieties were attached to the amines by reaction with p-chloromethylstyrene. Finally, dangling styrene moieties were crosslinked by a free-radical polymerization process initiated by AIBN and styrene, p-chloromethylstyrene or 2,3,4,5-pentafluorostyerene introduced in the mesopores. Polystyrene crosslinked aerogels are mechanically strong, lightweight (0.41-0.77 g cm(-3)), highly porous materials (they consist of ca. 63% empty space, with a BET surface areas in the range of 213-393 m(2) g(-1)). Their thermal conductivity (0.041 W m(-1) K-1) is comparable to that of glass wool. Hydrophobicity, however, is the property that sets the new material apart from analogous polyurea and epoxy crosslinked aerogels. The contact angles of water droplets on disks cut from larger monoliths are >120 degrees. (By comparison, the contact angle with polyurea crosslinked aerogels is only ca. 60 degrees.) Polystyrene crosslinked aerogel monoliths float on water indefinitely, while their polyurea counterparts absorb water and sink within minutes.
引用
收藏
页码:3046 / 3054
页数:9
相关论文
共 62 条
[1]   THERMAL-CONDUCTIVITY AND HEAT-CAPACITY OF AMORPHOUS SIO2 - PRESSURE AND VOLUME DEPENDENCE [J].
ANDERSSON, S ;
DZHAVADOV, L .
JOURNAL OF PHYSICS-CONDENSED MATTER, 1992, 4 (29) :6209-6216
[2]  
[Anonymous], REV PHYS APPL
[3]  
Brinker C.J., 1990, SOL GEL SCI
[4]  
Callister Jr WD, 2007, Materials science and engineering: an introduction
[5]   FUNCTIONAL POLYMERS SUPPORTED ON POROUS SILICA .1. GRAFTING ACTIVE PRECURSORS ONTO POROUS SILICA [J].
CARLIER, E ;
GUYOT, A ;
REVILLON, A ;
LLAURODARRICADES, MF ;
PETIAUD, R .
REACTIVE POLYMERS, 1991, 16 (01) :41-49
[6]  
Caruso F, 2001, ADV MATER, V13, P11, DOI 10.1002/1521-4095(200101)13:1<11::AID-ADMA11>3.0.CO
[7]  
2-N
[8]   Preparation and characterization of ordered nanoparticle and polymer composite multilayers on colloids [J].
Caruso, F ;
Möhwald, H .
LANGMUIR, 1999, 15 (23) :8276-8281
[9]  
Caruso F, 1999, ADV MATER, V11, P950
[10]   Electrostatic self-assembly of silica nanoparticle -: Polyelectrolyte multilayers on polystyrene latex particles [J].
Caruso, F ;
Lichtenfeld, H ;
Giersig, M ;
Möhwald, H .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1998, 120 (33) :8523-8524