Peer-Reviewed Publications



PresentationsAnn Fenech receiving the IoP Printing and Graphic Science Conference award from Alan Hodgson




Publication Abstracts

Fenech A, Strlic M, Degano I and Cassar M: "Stability of Chromogenic Colour Prints in Polluted Indoor Environments", Polymer Degradation and Stability (in print)

Chromogenic colour prints are known to be sensitive to storage environments. However, limited research is available on the effect of atmospheric pollutants on these materials, especially pollutants generated indoors. The stability of photographic dyes is of particular interest and the rate of their change can be best described using the standard RGB colour model. Therefore, the colourimetric method was compared to dye extraction and liquid chromatographic analysis to justify its use as a rapid, non-destructive method for quantitative assessment of the rate of change in dye content of colour photographs during degradation. The effects of typical indoor (acetic acid, formaldehyde) and outdoor (nitrogen dioxide) generated pollutants on chromogenic colour prints were then investigated at 80 °C, 60% RH. It was identified that acetic acid leads to the most pronounced changes in photographic dye concentrations, which is significant considering that acetic acid is often the most prominent pollutant in archival environments. On the other hand, formaldehyde exhibited a slight protective effect in comparison to the blank experiment.

Keywords: Colour photographs; Dye stability; Colourimetry; Chromatography; Indoor environment; Pollution; Accelerated degradation

Fenech A, Strlic M, Cigic IK, Levart A, Gibson LT, de Bruin G, Ntanos K, Kolar J and Cassar M: "Volatile Aldehydes in Libraries and Archives", Atmospheric Environment, 44, 2010, 2067-2073.

Volatile aldehydes are produced during degradation of paper-based materials. This may result in their accumulation in archival and library repositories. However, no systematic study has been performed so far. In the frame of this study, passive sampling was carried out at ten locations in four libraries and archives. Despite the very variable sampling locations, no major differences were found, although air-filtered repositories were found to have lower concentrations while a non-ventilated newspaper repository exhibited the highest concentrations of volatile aldehydes (formaldehyde, acetaldehyde, furfural and hexanal). Five employees in one institution were also provided with personal passive samplers to investigate employees’ exposure to volatile aldehydes. All values were lower than the presently valid exposure limits. The concentration of volatile aldehydes, acetic acid, and volatile organic compounds (VOCs) in general was also compared with that of outdoor-generated pollutants. It was evident that inside the repository and particularly inside archival boxes, the concentration of VOCs and acetic acid was much higher than the concentration of outdoor-generated pollutants, which are otherwise more routinely studied in connection with heritage materials. This indicates that further work on the pro-degradative effect of VOCs on heritage materials is necessary and that monitoring of VOCs in heritage institutions should become more widespread.

Keywords: Air quality, health and safety, indoor emission, paper degradation, VOC

Fenech A, Schiro J, Farrugia C, and Baluci C: "A Comparative Study of the Effects of Cleaning Treatments on Two Historic Papers: A Preliminary Study" in Varella, E.A. and Caponetti E. in Proceedings of the 2nd Chemistry and Conservation Science Residential Summer School (Societa Chimica Italiana & ECTN)

This study aimed to investigate the effects of wet-cleaning treatments, namely immersion washing and simple chemical treatments involving bleaching with a 15% hydrogen peroxide solution or deacidification in a 2% solution of calcium hydroxide, as well as combinations of these two chemical treatments on an 18th century and a late 19th century paper. The effect of these cleaning treatments was analysed through the monitoring of the colorimetric properties (CIE L*a*b* coordinates), crystallinity index (X-Ray diffraction), pH (cold-extraction method), degree of polymerisation (viscometry), and carbonyl content (modified Szabloc Methodology). It was determined that all cleaning treatments significantly affected the colorimetric properties of the two sheets. However, the degree of crystallinity and the degree of polymerization were not found to differ significantly upon cleaning. Carbonyl content and pH varied to different degrees depending on the treatment used. Correlations were also recorded between properties investigated via destructive techniques and the non-destructive colorimetric method, indicating that this technique may be used as a non-destructive indicator of the extent of degradation. However, further studies on a larger sample size is required for this system to be developed.

Keywords: cellulose, paper, determination, degree of polymerization, degree of crystallinity, acidity, analysis, carbonyl content, colorimetry