Nano calcium carbonate versus nano calcium hydroxide in alcohols as a deacidification medium for lignocellulosic paper

Abstract

Deacidification is an established conservation treatment for the prolongation of the acidic paper stability. Several different deacidification systems are in use today, such as the dispersions of alkaline nanoparticles in organic solvents. The aim of the study was to compare the effects of different calcium nanoparticle dispersions in alcohols on lignocellulosic paper. Commercially available nano calcium hydroxide dispersions for paper deacidification, and laboratory prepared nano calcium carbonate dispersions in ethanol and 2-propanol were investigated and compared as to their effectiveness in increasing the stability of paper. The FE-SEM analyses were used to determine the size of Ca(OH) 2 and CaCO 3 particles in the dispersions. The SEM-EDS analyses were performed both on the paper surface and its crosssection in order to ascertain the distribution of calcium ions following the deacidification treatment. An evaluation of the changes of color, molecular weight, pH and alkaline reserve on different lignocellulosic papers was performed. In comparison to untreated samples, our results indicate all the investigated deacidification treatments decrease the degradation rate constant of cellulose, as determined by accelerated degradation. However, the treatments involving nano calcium hydroxides in both alcohols noticeably affect the color of the treated lignocellulosic papers. According to the obtained results, nano calcium carbonate is therefore the more suitable deacidification agent for the lignin containing papers.

Assessment of the Robustness of a Color Monitoring Chart Calibration Method for Crowdsourcing-Based Preventive Conservation

“…Based on those tables, the CIEDE2000 differences for each one of the four materials under study are shown graphically (Figure 3). In general, the color patches with inks printed upon them show a relatively slow degrading, with a barely steep slate, staying in most cases under the ∆E 00 CIEDE2000 < 1.5 threshold, implying a minimal perceivable color difference, only noticeable by trained eyes [25][26][27]. This indicates good stability and robustness in the considered exposition period.…”

Recent Research and Prospect of Deacidifying Materials for Paper and Paper-based Cultural Relics

“…Bicchieri 等 [45] 考察了碳酸钙和丙酸钙纳米粒子在纸张 脱酸中的效果, 处理后纸张的 pH 值可提高 3～4 个单位. Malešič 等 [46] 将纳米碳酸钙(粒径约 100 nm)分别分散在 乙醇和异丙醇溶剂中制备浓度均为 0. 此外, 还有在所用溶剂中可以完全电离或者在低于 其饱和溶解度浓度下的可以形成均相溶液的离子形态 脱酸材料(表 2p～2t).…”

Recent Developments in the Application of Inorganic Nanomaterials and Nanosystems for the Protection of Cultural Heritage Organic Artifacts

“…As emerging from the literature, the most promising morphology is represented by the nanosheets' morphology, which allows for not only the development of the alkaline reserve, but it also covers the paper fibers, acting as lamination sheet, as a first line of defense against acid attack from environmental sources [33]. Calcium and sodium carbonates are also common apparition in literature studies as sources of alkaline reserve [42,46].…”