1 z e zyxwvutsrqpon 0 zyxwvut Copyright 1994 American Chemical Society zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA The ACS Joumal of Surfaces and Colloids JULY zy 1994 VOLUME 10, NUMBER zy 7 Letters Utilization of Surfactant-Stabilized Colloidal Silver Nanocrystallites in the Construction of Mono- and Multiparticulate Langmuir-Blodgett Films F. C. Meldrum, N. A. Kotov, and J. H. Fendler* Department zyxwvutsrq of Chemistry, Syracuse University, Syracuse, New York 13244-41 00 Received January 3, 1994. In Final Form: April 25, 1994@ Oleic acid-stabilized 100-&diameter silver particles have been spread at air-water interfaces in a Langmuir film balance. Surface pressure us surface area isotherms, reflectivity measurements, and Brewster-angle and transmission electron microscopies demonstrated that increasing surface pressure resulted in the transition from gaseous and liquid phases of mixed oleic aciasilver particle domains to closelypacked, well-separated monoparticulate silver domains which ultimatelycollapsed to multiparticulate layers. Sequential transfer to solid substrates by the Langmuir-Blodgett technique led to the formation of multiparticulate layers of silver clusters. Introduction The unique optical and electrooptical properties of ultrathin silver films and nanosized silver particles have prompted the increasing interest of chemists, physicists, and materials scientists in this area.'+' Silver particulate films, generated under monolayers by electrocrystalliza- ti~n~,~ and chemical reduction,6represent an intermediate between solid films and colloidal particles. Importantly, the silver particulate films are nanocrystalline in nature and can be investigated in situ under surfactant mono- layers, as well as ex situ subsequent to their transfer to solid substrates. Thus, silver particulate films, like the analogous semiconductor particulate films developed in our lab~ratories,~ provide a membrane-mimetic approach to advanced materiaha zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA @ Abstract published in Advance ACS Abstracts, June 1, 1994. (1) Henglein, A. Isr. J. Chem. 1993, 33,77. (2) Raether, H. Surface Plasmons on Smooth and Rough Surfaces and on Gratings; Springer-Verlag: Berlin, 1988. (3) Efrima, S. Crit. Rev. Surf Chem. 1991, 1, 167. (4) Zhao, X. K.; Fendler, J. H. J. Phys. Chem. 1990,94, 3384. (5) Kotov, N. A.; Zaniquelli, M. E. D.; Meldrum,F. C.; Fendler, J. H. (6) Yi, K. C.; Hbrvolgyi, Z.; Fendler, J. H. In press. (7) Fendler, J. H. zyxwvutsr Zsr. J. Chem. 1993, 33,77. (8) Fendler, J. H. Membrane-Mimetic Approach to Advanced Materi- Langmuir 1993,9, 3710. als; Springer-Verlag: Heidelberg, 1994. Preparation of monoparticulate layers of dodecylben- zenesulfonic acid-stabilized CdS nanoclusters and their subsequent sequential transfer to solid substrates by the Langmuir-Blodgett (LB) technique have furnished an alternative means for superlattice constru~tion.~ This methodology has been extended to other nanoparticulate layers. The preparation and characterization of oleic acid- stabilized silver particulate layers are the subjects of the present paper. Although traditionally prepared in aqueous solution, metal particles may also be dispersed in nonaqueous solution. This can be achieved by a solvent extraction/ reduction technique in nonpolar so1vent,l0J1 by physical methods such as the gas evaporation technique,I2in polar solvents such as methanol and ethanol in the presence of polymeric stabilizers,13J4 by reduction of an organometallic (9) Kotov, N. A.; Meldrum, F. C.; Wu, C.; Fendler, J. H. J. Phys. (10) Meguro, K.; Torizuka,M.; Esumi, K. Bull. Chem.SOC. Jpn. 1988, (11) Eeumi, K.; Shiratori, M.; Ishizuka, H.; Tana, T.; Tongue, K.; (12) Kimura, K.; Bandow, S. Bull. Chem. SOC. Jpn. 1983, 56, 33. (13) Hirai, H. J. Mmromol. Sci. Chem. 1979, A13,633. (14) Hirai, H.;Nakao, Y.; Toshima, N. J. Macromol. Sci. Chem. 1979, Chem. 1994,98,2735. 61,341. Meguro, K. Langmuir 1991, 7, 457. A13,727. 0743-7463/94/2410-2035$04.50lO zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA 0 1994 American Chemical Society