title: Helium ion microscopy based wall thickness and surface roughness analysis of polymer foams obtained from high internal phase emulsion.
abstract: Due to their wide range of applications, porous polymers obtained from high internal phase emulsions have been widely studied using scanning electron microscopy. However, due to their lack of electrical conductivity, quantitative information of wall thicknesses and surface roughness, which are of particular interest to tissue engineering, has not been obtained. Here, Helium Ion Microscopy is used to examine uncoated polymer foams and some very strong but unexpected contrast is observed, the origin of which is established here. Based on this analysis, a method for the measurement of wall thickness variations and wall roughness measurements has been developed, based on the modeling of Helium ion transmission. The results presented here indicate that within the walls of the void structure there exist small features with height variations of ~30 nm and wall thickness variations from ~100 nm to larger 340 nm in regions surrounding interconnecting windows within the structure. The suggested imaging method is applicable to other porous carbon based structures with wall thicknesses in the range of 40-340 nm.
authors: Department of Materials Science & Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK. Electronic address: c.rodenburg@sheffield.ac.uk.
authors: C
authors: C
authors: Rodenburg
authors: Department of Biomedical Sciences, University of Sheffield, Firth Court, Western Bank Sheffield, Sheffield S10 2 TN, UK.
authors: P
authors: P
authors: Viswanathan
authors: Department of Materials, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK.
authors: M A E
authors: MA
authors: Jepson
authors: Carl Zeiss Microscopy GmbH, Carl-Zeiss-Strasse 22, 73447 Oberkochen, Germany.
authors: X
authors: X
authors: Liu
authors: Department of Chemistry University College London, 20 Gordon Street, London WC1H 0AJ, UK; The MRC/UCL Centre for Medical Molecular Virology, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
authors: G
authors: G
authors: Battaglia
mesh_terms: D006371:Helium / Q000737:chemistry*; D007477:Ions / Q000737:chemistry*; D008853:Microscopy / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D007477:Ions; D011108:Polymers; D006371:Helium