Raman spectroscopy
Analyte
- Solid and liquid polymers; composites, materials, organic and anorganic low-molecular substances, thin layers, fibres, solution
- Sample amount: ca. 1 mg
Equipment
Bruker RFS 100/S FT Ramanspektrometer with coppled RamanScope III microscope and light-conducting fiber with head RAMPROBE
- Spectral range 3600 – 50 cm-1 (Stokes) and 100 – 2000 cm-1 (anti-Stokes)
- Fluorescence-free Raman spectra by excitation at 1064 nm (Nd:YAG-Laser)
- liquid nitrogen cooled, Ge detector
- Objective: 10x, NA = 0,25; WD = 6,5 mm und 100x, NA = 1,25; WD = 0,15 (microscope)
- motorised sample stage, intercept length 1 µm (microscope)
- Immersion tube: RT201-25, maximum operating temperature: 180 °C, maximum pressure: 2 bar
- Variable temperature cell
Evaluation methods and targets
Fluorescence-free Raman spectra
- Wave number
- Raman intensity
Aim
- Idendification of functional groups
- Quantitative determination of degrees of substitution of polysaccharides
- Characterisation of cellulose structures
- Investigation of cellulose modification in solutions or melts
- Reaction control by online measurement in the reactor
- FT Raman microscopy at plant fibres
Application examples
- Determination of degrees of substitution of carboxymethyl starch, carboxymethyl cellulose and starch acetate