The document discusses using atomic force microscopy combined with infrared spectroscopy (AFM-IR) to characterize particles at the nanoscale by obtaining both topographic and chemical information. Specifically, it details how AFM-IR was used to differentiate between PMMA beads and epoxy, identify polystyrene and melamine beads, and analyze a lake water sample to chemically identify particles as small as 20-100 nm.

1. What’s in the Water?
Particle Characterization using AFM/IR
Topographic and Chemical Information
Mark Banaszak Holl
January 2016
Anasys NanoIR2

2. Height Deflection
Optical Microscopy
Differentiating Composition
PMMA Beads in Epoxy
AFM Images
IR Spectra
PMMA
Epoxy

3. IR Imaging
1512 cm-1
epoxy
1730 cm-1
PMMA
Ratio

4. Polystyrene (0.5 µm ) and Melamine (1 µm ) Beads
Height (tapping)
Height (tapping)
MelaminePolystyrene

5. AFM-IR on Lake Water Sample
Rachel Merzel and Rachel Cable
Sample from Duhaime Lab
Sample: 20-100 nm fraction
Cloudy, yellow-brown supernatant
sediment at the bottom
Optical image
AFM topography image
Silica!
Stiffness map