氧化纤维素纳米晶Pickering乳液的制备、表征及应用

Preparation,characterization and application of pickering emulsion stabilized by oxidized cellulose nanocrystalline

【目的】以改性的方法提高纤维素纳米晶的水溶性,用其制备稳定的水包油型Pickering乳液,并初步探究Pickering乳液在制备复乳和包埋益生菌中的潜在应用价值.【方法】首先,采用TEMPO(2,2,6,6-tetramethylepiperidin-1-oxyl,2,2,6,6-四甲基哌啶-1-氧自由基)/NaBr/NaClO体系对微晶纤维素进行化学改性,分别制备氧化度为30%、50%和100%的氧化纤维素纳米晶,通过扫描电子显微镜和红外光谱分别对其形貌和羧基化学结构进行测定.其次,用氧化纤维素纳米晶制备Pickering乳液,用荧光显微镜和Turbi Scan稳定性分析仪分别对其形态和稳定性进行表征和分析.最后,用氧化纤维素纳米晶制备复乳,并将上述制备的Pickering乳液用于菌体包埋,用激光共聚焦显微镜进行观察.【结果】氧化后的纤维素纳米晶结构疏松,羧基含量增加,水溶性随氧化度的升高而增加;氧化度为50%的纤维素纳米晶制备的Pickering乳液较稳定,其也可用来制备W/O/W型乳液,而且Pickering乳液用于菌体包埋,有较好的包埋效果.【结论】氧化后的纤维素纳米晶能够制备出稳定性较好的Pickering乳液,该Pickering乳液可以用于制备W/O/W型复乳以及菌体的包埋,具有潜在的应用价值.

【Objective】It is necessary to improve the water solubility of cellulose nanocrystalsby modified method so that it can be used to prepare the stableoil-in-water Pickering emulsion.And the potential application value of Pickering emulsion in embedding and preparation of double emulsion was investigated.【Method】Firstly,the cellulose nanocrystals were chemically modified by TEMPO(2,2,6,6-tetramethyl-1-piperidinyloxy)/NaClO/NaBr oxidation system,we prepared cellulose nanocrystals with oxidation degree(DO)of 30%,50%and 100%.The morphology was characterized by scanning electron microscopy(SEM),and the carboxyl chemical structure was determined by Fourier transform infrared spectrometry(FT-IR).Then the morphology of Pickering emulsion made with oxidized cellulose nanocrystals were characterized by fluorescence microscopy.The stability of the emulsion was analyzed via Turbi Scan stability analyzer.Finally,a W/O/W emulsion was prepared by using cellulose nanocrystals with an oxidation degree of 50%,and theapplication of Pickering emulsion in bacteria embedding was investigated by laser scanning confocal microscope(LSCM).【Result】The results showed that the structure of oxidized cellulose nanocrystal is loose,the amount of carboxyl groups were greatly improved and water-solubility of obtained cellulose nanocrystals increased with the increase of DO;It was proved that a stable Pickering emulsion was prepared by using cellulose nanocrystals with an oxidation degree of 50%,which also can prepare W/O/W emulsion.In addition,Pickering emulsion is used for bacterial embedding and has good effect of embedding.【Conclusion】The oxidized cellulose nanocrystals can prepare Pickering emulsion with good stability.The Pickering emulsion can be used to prepare W/O/W type double emulsion and embedding of bacterial,which has potential application value.