Method for determining surface properties of microparticles

Patent · Sat Jan 01 00:00:00 EST 2000

OSTI ID:872968

Eisenthal, Kenneth B ^[1]

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1. Ridgewood, NJ

Second harmonic generation (SHG), sum frequency generation (SFG) and difference frequency generation (DFG) can be used for surface analysis or characterization of microparticles having a non-metallic surface feature. The microparticles can be centrosymmetric or such that non-metallic molecules of interest are centrosymmetrically distributed inside and outside the microparticles but not at the surface of the microparticles where the asymmetry aligns the molecules. The signal is quadratic in incident laser intensity or proportional to the product of two incident laser intensities for SFG, it is sharply peaked at the second harmonic wavelength, quadratic in the density of molecules adsorbed onto the microparticle surface, and linear in microparticles density. In medical or pharmacological applications, molecules of interest may be of drugs or toxins, for example.

• Research Organization: Columbia Univ., New York, NY (United States)
• DOE Contract Number: FG02-91ER14226
• Assignee: Trustees of Columbia University in City of New York (New York, NY)
• Patent Number(s): US 6055051
• OSTI ID: 872968
• Country of Publication: United States
• Language: English

Related Subjects

method
determining
surface
properties
microparticles
harmonic
generation
shg
frequency
sfg
difference
dfg
analysis
characterization
non-metallic
feature
centrosymmetric
molecules
centrosymmetrically
distributed
inside
outside
asymmetry
aligns
signal
quadratic
incident
laser
intensity
proportional
product
intensities
sharply
peaked
wavelength
density
adsorbed
microparticle
linear
medical
pharmacological
applications
drugs
toxins
example
surface feature
incident laser
surface properties
difference frequency
surface analysis
laser intensities
frequency generation
harmonic generation
particle surface
metallic surface
determining surface
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