2. Materials and methods
2.1. LDPE test films
A TiN dispersion with 8% TiN in white mineral oil was
provided by Colormatrix, UK. A TiN-/LDPE masterbatch was
produced by compounding the dispersion into a neat LDPE
matrix (Lupolen 1806 H, LyondellBasell). LDPE films with three
different concentrations of TiN in the polymer (LDPE A, B and
C) were extruded using a Collin flat film extruder (Dr. Collin
GmbH, Germany). The TiN-/LDPE masterbatch was mixed
again with the same LDPE used for the masterbatch and was
extruded to films of 60 mm thickness. LDPE blanks without TiN
were produced in the same way as reference (LDPE 0). Thus,
LDPE films with intended (nominal) concentration of
0 mg kg1 (LDPE 0), 100 mg kg1 (LDPE A), 500 mg kg1 (LDPE
B) and 1000 mg kg1 (LDPE C) TiN were produced.