Deacidification of Paper Using Supercritical Carbon Dioxide Containing Calcium Propionate or Magnesium Bicarbonate

Abstract

Supercritical carbon dioxide (SCCO2) containing calcium propionate or magnesium bicarbonate was used to deacidify paper. In the experiment, to compare the effects of SCCO2 technology deacidification and immersion deacidification, two kinds of paper samples were chosen to do these two kinds of deaciditication tests respectively. And pH, alkali reserve and mechanical properties of paper samples were measured before and after these treatments. The experiments showed that the pH and alkaline reserve of paper samples treated with SCCO2 were nearly similar to that of immersion treatments. Otherwise, compared with immersion deacidification, supercritical carbon dioxide had some advantages of strengthening the mechanical properties of paper and shortening treatment time.

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

“…超临界流体具有优异的扩散性、低表面张力和低黏 度, 可以加快传质速率, 促进小尺寸颗粒的渗透. Fang 课题组 [37] 分别采用氢氧化钙(Ca(OH) 2 )和乙酸镁的乙醇 水溶液(乙醇与水体积比 50∶50)的超临界 CO 2 对纸张进 行了脱酸, 分别与各自脱酸材料的浸渍法脱酸相比较, 处理后纸张的初始 pH 值均相差不大, 老化 72 h 后, 超 临界 CO 2 方法处理的纸张具有较高的 pH 值、较多的碱 性储备和增强的机械强度; 在纸张具有相近的脱酸效果 时, 超临界方法可以减少对纸张脱酸的处理时间 [38] . 此 外, Weng 等 [39] 采用 Ca(OH…”

Proof-of-Concept Study on the Feasibility of Supercritical Carbon Dioxide-Assisted Consolidation Treatment for a Pair of Goalkeeper Gloves on Synthetic Latex-Based Foam Mock-Ups

“…Examples of scCO 2 -assisted impregnation include the impregnation process for the dyeing of synthetic and natural textiles [28,29], preparation of drug-eluting implants [30][31][32][33][34][35][36][37], softwood processing [38][39][40][41][42][43], the preparation of hybrid silk material [44] or for food packaging applications [45,46]. In the conservation field, supercritical CO 2 technology is still niche, with a few examples of application such as the cleaning of textiles [47][48][49][50][51], deacidification of paper [52][53][54][55][56] and the removal of pesticides from objects in ethnographic collections [57][58][59]. However, there are no examples of consolidation treatments (the equivalent to impregnation as a conservation treatment), except for a study by Tuminello et al on the solubility of fluorinated resins in liquid CO 2 and their application via CO 2 spraying for stone preservation [60].…”

Assessing the Use of Supercritical Carbon Dioxide as a Carrier for Alkoxysilanes to Consolidate Degraded PUR Ester Foams: An Alternative to Traditional Methods

“…By matching the ideal T and p conditions with the material and treatment, scCO2 may be advantageous in various conservation processes including cleaning, decontamination, deacidification, stabilisation, consolidation, and drying [25,27,28]. Recent publications have studied the application of scCO2 to paper [27,29,30], wood [28,31,32], textiles [33][34][35], waterlogged artefacts [36][37][38][39], archaeological heritage [40,41], and poly(methyl methacrylate) of historical value [42]. In the "PlasCO2: Green CO2 Technologies for the Cleaning of Plastics in Museums and Heritage Collections" project, conducted by the authors, scCO2 technology was used for the first time to design a conservation treatment for a pair of heavily degraded goalkeeper gloves from Museum Benfica-Cosme Damião.…”