Abstract: With sodium dodecyl sulfonate as phase transfer catalyst，N,N-dialkyl chitosan（N,N-DLCS-1 and N,N-DLCS-2）with different degree of substitution were prepared and characterized by FTIR，EA and 1H NMR. Properties of monolayers of these two samples were also studied. Experimental results showed that N,N-DLCS-1 has a higher degree of substitution，both samples could form a monolayer at the air-water interface. The sample N,N-DLCS-1 showed higher collapse pressure πc，maximum compressibility modulus Cs－1 and smaller extrapolated area Aex，the monolayer from which is more inseparable and stable due to the stronger intermolecular hydrophobic interaction derived from the higher degree of alkyl substitution.

摘要： 以壳聚糖和月桂醛为原料、十二烷基磺酸钠为相转移催化剂，制备N,N-双十二烷基化壳聚糖（N,N-DLCS），并进一步分离成两种不同取代度的产物N,N-DLCS-1和N,N-DLCS-2。用FTIR、EA和1H NMR等方法进行表征，并研究其单分子膜性能。结果表明：N,N-DLCS-1的烷基取代度较高，N,N-DLCS-2较小。两种样品均可在水面上形成单分子膜，其中N,N-DLCS-1的崩溃压πc较高，极限分子占据面积Aex较小，最大压缩模量Cs－1较大，单分子膜的凝聚性和稳定性更好。单分子膜的致密度和稳定性随着取代度的增加而增大。