Cocoon-in-Web-Like Superhydrophobic Aerogels from Hydrophilic Polyurea and Use in Environmental Remediation

被引:88
作者
Leventis, Nicholas [1 ]
Chidambareswarapattar, Chakkaravarthy [1 ]
Bang, Abhishek [1 ]
Sotiriou-Leventis, Chariklia [1 ]
机构
[1] Missouri Univ Sci & Technol, Dept Chem, Rolla, MO 65409 USA
关键词
aerogels; polyurea; superhydrophobic; Cassie-Baxter; hydrogen bonding; oil spill cleanup; X-RAY-SCATTERING; SURFACES; LOTUS; POLYSTYRENE; FILMS; NMR; OIL;
D O I
10.1021/am500685k
中图分类号
TB3 [工程材料学];
学科分类号
0805 ; 080502 ;
摘要
Polyurea (PUA) develops H-bonding with water and is inherently hydrophilic. The water contact angle on smooth dense PUA derived from an aliphatic triisocyanate and water was measured at theta = 69.1 +/- 0.2 degrees. Nevertheless, texture-related superhydrophobic PUA aerogels (theta' = 150.2 degrees) were prepared from the same monomer in one step with no additives, templates, or surfactants via sol gel polymerization carried out in polar, weakly H-bonding acetonitrile. Those materials display a unique nanostructure consisting of micrometer-size spheres distributed randomly and trapped in a nanofiber web of the same polymer. Morphostructurally, as well as in terms of their hydrophobic properties, those PUA aerogels are analogous to well-studied electrospun fiber mats incorporating particle-like defects. PUA aerogels have the advantage of easily scalable synthesis and low cost of the raw materials. Despite large contact angles and small contact areas, water droplets (5 mu L) stick to the aerogels surface when the substrate is turned upside-down. That so-called Petal effect is traced to H-bonding at the points of contact between the water droplet and the apexes of the roughness of the aerogel surface. Monoliths are flexible and display oleophilicity in inverse order to their hydrophobicity; oil fills all the available open porosity (94% v/v) of cocoon-in-web like aerogels with bulk density rho(b) = 0.073 g cm(-3); that capacity for oil absorption is >10:1 w/w and translates into similar to 6:1 w/v relative to state-of-the-art materials (e.g., graphene-derived aerogels). Oil soaked monoliths float on water and can be harvested off.
引用
收藏
页码:6872 / 6882
页数:11
相关论文
共 51 条
[1]   Porous materials for oil spill cleanup: A review of synthesis and absorbing properties [J].
Adebajo, MO ;
Frost, RL ;
Kloprogge, JT ;
Carmody, O ;
Kokot, S .
JOURNAL OF POROUS MATERIALS, 2003, 10 (03) :159-170
[2]  
Bang A., 2014, PMSE PREPR, V110, P000
[3]   Purity of the sacred lotus, or escape from contamination in biological surfaces [J].
Barthlott, W ;
Neinhuis, C .
PLANTA, 1997, 202 (01) :1-8
[5]   Small-angle scattering from polymeric mass fractals of arbitrary mass-fractal dimension [J].
Beaucage, G .
JOURNAL OF APPLIED CRYSTALLOGRAPHY, 1996, 29 (pt 2) :134-146
[6]   Pearl drops [J].
Bico, J ;
Marzolin, C ;
Quéré, D .
EUROPHYSICS LETTERS, 1999, 47 (02) :220-226
[7]   A smooth future? [J].
Bocquet, Lyderic ;
Lauga, Eric .
NATURE MATERIALS, 2011, 10 (05) :334-337
[8]   POROSITY BY SMALL-ANGLE X-RAY-SCATTERING (SAXS) - COMPARISON WITH RESULTS FROM MERCURY PENETRATION AND NITROGEN ADSORPTION [J].
BRENNER, AM ;
ADKINS, BD ;
SPOONER, S ;
DAVIS, BH .
JOURNAL OF NON-CRYSTALLINE SOLIDS, 1995, 185 (1-2) :73-77
[9]  
Callies M, 2005, SOFT MATTER, V1, P55, DOI 10.1039/b501657f
[10]   Wettability of porous surfaces. [J].
Cassie, ABD ;
Baxter, S .
TRANSACTIONS OF THE FARADAY SOCIETY, 1944, 40 :0546-0550