中文摘要：

分别采用静态光散射法（SLS）和凝胶渗透色谱法（GPC）测定了木质素基高效减水剂GCL1-JB的分子量（Mw）.由于GCL1-JB直接溶于水中存在聚电解质效应和聚集现象，SLS法测得的分子量（Mw，SLS）远大于GPC测得的分子量（Mw，GPC）.为了通过SLS测得GCL1-JB的真实Mw，在GCL1-JB溶液中加入NaCl来屏蔽GCL1-JB的聚电解质效应，并采用0.45 μm的微孔滤膜滤除GCL1-JB聚集体.GCL1-JB的动态光散射测试中存在2个扩散峰：快模式峰和慢模式峰.快模式峰对应GCL1-JB的单分子行为，而慢模式峰对应GCL1-JB的聚电解质效应和GCL1-JB聚集体.GCL1-JB动态光散射的慢模式峰随着NaCl的不断加入和进一步的过滤处理而逐渐减弱.当NaCl在溶液中的浓度达到0.1 mol/L，动态光散射的慢模式峰完全消失.在没有慢模式峰存在的条件下利用SLS测得GCL1-JB的绝对分子量为121300，这个分子量被认为是GCL1-JB单分子的真实分子量.然而该条件下SLS法测得的Mw，SLS仍然比GPC法测得的Mw，GPC大，这是由于GCL1-JB与GPC标样NaPSS的构象差异引起的.GCL1-JB的分子构象比NaPSS的更卷曲，所以用NaPSS作为GPC标样得到Mw，GPC比GCL1-JB的真实分子量小.本研究提出了一种利用SLS准确测量GCL1-JB的Mw的方法，对存在聚电解质效应和聚集现象的木质素及其衍生产物的绝对分子量测定具有普遍的借鉴意义.

英文摘要：

The molecular weight （Mw） of the lignin-based superplasticizer GCL1-JB was determined by static light scattering （SLS） and gel permeation chromatography （GPC）.Results showed that the Mw value determined by SLS （Mw,SLS） was much larger than that determined by GPC （Mw,GPC） because of the polyelectrolyte effect and aggregation behaviors.To determine the real Mw of GCL1-JB by SLS,NaCl was added into the GCL1-JB solutions to restrain the polyelectrolyte effect,and the GCL1-JB dissolved in NaCl solution was further filtered by micro-filtration membrane with suitable pore size to remove the GCL1-JB aggregates.During DLS measurement of GCL1-JB,there existed two diffusion peaks：a fast mode and a slow mode.The fast mode is related to the GCL1-JB single molecules,and the slow mode is related to the polyelectrolyte effect and the GCL1-JB aggregates.The slow mode was inhibited gradually by adding NaCl followed by filtering,and finally disappeared when NaCl concentration reached 0.1 mol/L.With disappearance of the slow mode,Mw,SLS was determined to be 121300,which was considered to be the real Mw of GCL1-JB single molecules. Mw of GCL1-JB determined by SLS at this stage was still larger than that determined by GPC because of the difference in conformations between GCL1-JB and GPC standards （NaPSS）.The conformations of GCL1-JB was more curling than that of NaPSS; therefore,when NaPSS was used as the GPC standard,the Mw,GPC was smaller than the true Mw of the GCL1-JB.This work provides a method to determine the true Mw of GCL1-JB,which is significant for determining the absolute Mw of lignin and its derivatives that having polyelectrolyte effect and aggregation behaviors.