Spectrometry

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