Spectroscopic investigation of some derivatives of oxycellulose in cadoxen solution

Abstract

Condensation methods for the estimation of carbonyl groups in oxycellulose are briefly reviewed. The u.v. absorption spectra of solutions of oxycellulose and some of its derivatives in cadoxen have been examined. The results show that solutions of oxycellulose, its semicarbazide derivative and its thiosemicarbazide derivative are unsatisfactory for the spectrophotometric determination of carbonyl content, whereas the phenylhydrazine derivative may be used for an approximate determination; p‐nitrophenylhydrazine however is shown to be an excellent reagent for this determination.

Ageing of ancient paper: A kinetic model of cellulose degradation from Raman spectra

“…This band is expected to be strongly correspondent with the cellulose polymerization degree, its intensity decreasing as the polymerization degree decreases. The H–C–H and O–C–H in plane bending vibrations account for the less intense 1,425 cm −1 band, whilst C–O–H and H–C–C bending vibrations cause the 1,316‐cm −1 band . The latter vibrations also correlate with the bands at 1,335 and 1,376 cm −1 , respectively, and involve the internal vibration of the C–H groups, thus being weakly sensitive to structure variations.…”

“…A wide number of scientific works provides evidences on the chemical and physical properties of ancient and modern papers . Among the topics discussed, the main issue concerns the structure of cellulose and the related degradation processes.…”

“…Molecular chains are held together by strong intermolecular hydrogen bonds playing an important role in the aggregation of single chains into a highly oriented structure and conferring large tensile strength to cellulose fibers. On average, the aggregates are ordered up to even 80% (“crystalline” forms) whilst the remaining 20%, accounted as a disordered structure, is referred to “amorphous” form . Figure reports the Raman spectrum of some analysed ancient documents of C1 collection in the 1,000–1,800 cm −1 range, where main vibration bands of glucose molecules are expected.…”

“…Conservation and restoration of old documents is a thematic issue in library heritage, especially by operating a diagnostic analysis of paper materials in relation to the dating of paper sources . The goal is to prevent book damage in relation to ageing and to supply a guide to conservation and restoration activity .…”

“…In this respect, a fundamental issue is to investigate the chemical–physical properties of different kinds of paper, and inks used in ancient texts. To this end, the use of portable, non‐invasive, and non‐destructive techniques, such as Micro Raman spectroscopy, shows massive potential in the library research field, representing an effective solution when dimensions or conservation conditions of the artefacts impose safeguard constraints that prevent their analysis in a specific external laboratory . Recently, the exploitation of portable Near Infrared (NIR) μ‐Raman technique gave solid evidence of its usefulness in cultural heritage.…”