一种可推广的梯度科普实验设计:基于天然紫胶红色素酸碱变色原理  

A generalizable gradient popular science experiment design:based on the principle of acid-base discoloration of natural lac red pigment

作　　者：马骁 朱紫尚 张子涵 郭长彬[1] MA Xiao;ZHU Zishang;ZHANG Zihan;GUO Changbin(Department of Chemistry,Capital Normal University,Beijing 100048)

机构地区：[1]首都师范大学化学系,北京100048

出　　处：《首都师范大学学报（自然科学版）》2024年第6期89-96,共8页Journal of Capital Normal University：Natural Science Edition

基　　金：2022年度首都师范大学本科生科学研究与创业行动项目(318)。

摘　　要：为了设计一种绿色、安全且可推广的梯度科普实验,本文以天然紫胶红色素为研究对象,首先利用实验室常用试剂和家庭常用物品分别从中药材紫草茸中提取了紫胶红色素,对应命名为实验法和家庭法;其次对2种方法提取的紫胶红色素变色原理进行了验证;最后尝试面向不同年龄段的公众进行科普。实验法通过盐析法从紫胶中有效提取紫胶红色素,并初步验证了变色是基于紫胶红色素的酸碱电离平衡,可作为一种酸碱指示剂,具有强染色着色能力;其溶液在不同酸碱度下变色现象明显,酸碱度由低到高增加时,溶液颜色变化为黄色、橙黄色、橙色、橙红色、浅紫色到紫色。家庭法以实验法为基础,利用生活中具有类似物理化学性质的常见物品替代相应试剂,从中药材紫草茸中提取紫胶红色素,并验证变色反应。科普实验结果表明,利用天然紫胶红色素酸碱变色原理和染色剂,可以实现不同层次受众群的梯度科普实验。In order to design a green,safe and generalizable gradient science popularization experiment,this study takes the natural pigment lac red pigment as the research object.Firstly,the lac red pigment was extracted from the Chinese medicinal material comfrey mushroom using the common reagents in the laboratory and substances in the family,which named laboratory method and home method,respectively.Secondly,the discoloration principle of lac red pigment extracted by two methods was verified.Finally,the science popularization was tried for the public of different ages.The laboratory method was to effectively extract lac red pigment from lac by salting out method,and preliminarily verified that the discoloration of lac red pigment was due to the acid-base ionization balance of lac red pigment.And the discoloration phenomenon of lac red pigment solution at different pH is obvious,and when the pH increases from low to high,the color of the solution changes to yellow,orange-yellow,orange,orange-red,light purple to purple.It can be used as an acid-base indicator with strong dyeing and coloring ability.Based on laboratory method,the home method used common substances with similar physical and chemical properties to replace the corresponding reagents,extracts lac red pigment from Chinese medicinal material comfrey,and verifies the discoloration reaction of lac red pigment.Therefore,the use of natural lac red pigment acid-base discoloration principle and dyeing agent can achieve gradient science popularization experiments for different levels of audiences.

关 键 词：紫胶红色素 酸碱指示剂 梯度科普 天然色素 染色剂 

分 类 号：O629[理学—有机化学]