Volume 41, Issue 2 -

The crystallinity indices (CrI) of Chinese handmade papers were investigated using the X-ray diffraction (XRD) method. Four Chinese handmade papers, Yingchun , Zhuma , Yuanshu and Longxucao papers were used as model substrates of mulberry bark, ramie, bamboo and Eulaliopsis binata papers, respectively. Two forms of the paper samples, paper sheets and their comminuted powders, were used in this study. The results showed that their XRD patterns belong to the cellulose-I type and I β dominates the cellulose microstructure of these paper samples. Moreover, it was found that the microstructures and CrIs of cellulose of these papers were changed by the grinding treatment. This work suggested that the sheet form of the handmade papers is suitable to determine CrI by XRD, despite the contribution of non-cellulosic components in the papers. The order of CrIs for these paper sheet samples was Yingchun , Zhuma , Longxucao and Yuanshu papers. Besides CrIs, differences in cross-sectional areas of the crystalline zone of cellulose can be used for comparing different types of handmade papers. It was also found that the CrIs and crystallite size of paper cellulose varied between the sheet samples and the powder samples, illustrating that the pulverisation has a negative influence on the microstructure of the handmade papers.

Theft of archival documents constitutes a serious problem for archives. A possible solution to this problem lies in labelling these documents with codes that are invisible to the naked eye. A possible method could involve use, e.g. of the oxides of lanthanum, dysprosium, samarium, gadolinium and niobium, which have good responses in the XRF spectrum and are normally not present in archival materials. This study is concerned with the impact of these oxides on the properties of lignocellulosic materials. The identification tags were printed on three different kinds of paper supports (Whatman No. 1 filter paper, paper according to ISO 9706 and sulphite pulp). The colour change, average degree of polymerisation, the pH values of an aqueous extract and selected mechanical properties after application of the tag and artificial ageing were studied on all the samples. The measurements showed that the studied oxides do not have a negative effect on the monitored properties of the paper supports and do not affect their long-term ageing behaviour.

Hydrogen peroxide (HP) residues that remain after the conversion of blackened lead white may cause unwanted paper discolouration and degradation. Four VOCs sorption materials were tested for their ability to eliminate HP gas evolving from the treated substrate. This was tested by measuring the change in HP concentration in aqueous solution and in an enclosed air space in the presence of MicroChamber ® Interleaving Paper, Corrosion Intercept ® film, Zorflex ® activated carbon cloth (ACC) and iron sulphate-impregnated paper. Detection with the colour indicator Quantofix ® test strips and a Dräger X-am ® 5100 single gas detection device showed that ACC is by far most efficient in decreasing the HP concentration. ACC was also effective in preventing paper discolouration in test objects that had been HP-treated for lead white conversion and then were stored sandwiched between ACC. Although ACC may not eliminate all HP from the substrate, it can diminish its negative effects on the treated object and protect other objects in the vicinity.