Surface behavior and buckling of silver interfacial colloid films

We study the surface behavior of Langmuir films of highly concentrated inte rfacial colloids composed of flocculated silver nanoparticles located at th e liquid-liquid interface of water and dichloromethane. Pressure/area isoth erms and W-visible absorption-reflection spectra are acquired in situ simul taneously. The behavior is discussed in terms of the colloid particle size and concentration. A reversible buckling of the film is observed at about 2 0-22 erg/cm(2), with a creased three-dimensional phase replacing the smooth two-dimensional phase. The temperature dependence of the pi /A curves is m easured and discussed, particularly in relation to the buckling of the film . This work bridges over the size gap between the behavior of monoparticula te films of nanoparticles and those of micron-size glass and latex particle s.