Wang Zhuorui, Cheng Cong, Cheng Yongjuan, Zheng Lizhen, Hu Daodao
Engineering Research Center of Historical Cultural Heritage Conservation, Ministry of Education, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an 710119, China.
School of Historical Culture and Tourism, Xi'an University, Xi'an 710065, China.
Nanomaterials (Basel). 2021 Jun 30;11(7):1726. doi: 10.3390/nano11071726.
Traditionally, the acidity of paper-based relics was determined by an extraction method and using a pH meter. This method could not obtain the total acidity of the paper-based relics because it only detected the concentration of free protons in the aqueous soaking solution. To overcome this defect, a new method for determining the total acidity of paper-based relics has been established by using quaternary alloy quantum dots. The quantum dots, CdZnSeS, modified by p-Aminothiophenol (pATP) were prepared, and their composition and structure were characterized. The fluorescence behavior of prepared quantum dots with acidity was investigated. The following results were obtained. The fluorescence of CdZnSeS-pATP quantum dots could decrease with increases in acidity because pATP dissociated from the surfaces of the quantum dots due to protons or undissociated weak acids. Based on this feature, a method for determining the acidity of paper-based relics was constructed, and this method was used to evaluate the acidity of actual paper-based relics. Obviously, for a given paper sample, since both free protons and bound protons can be determined by this method, the acidity measured by this method is more reasonable than that by pH meter.
传统上，纸质文物的酸度是通过萃取法并使用pH计来测定的。这种方法无法获得纸质文物的总酸度，因为它只检测了水性浸泡溶液中游离质子的浓度。为了克服这一缺陷，已建立了一种使用四元合金量子点测定纸质文物总酸度的新方法。制备了用对氨基硫酚（pATP）修饰的量子点CdZnSeS，并对其组成和结构进行了表征。研究了所制备量子点的荧光行为与酸度的关系。得到了以下结果。CdZnSeS-pATP量子点的荧光会随着酸度的增加而降低，这是因为由于质子或未解离的弱酸，pATP从量子点表面解离。基于这一特性，构建了一种测定纸质文物酸度的方法，并将该方法用于评估实际纸质文物的酸度。显然，对于给定的纸张样品，由于该方法可以同时测定游离质子和结合质子，因此用该方法测得的酸度比用pH计测得的更合理。
