Liu Ying, Shi Zicong, Zou Yujun, Yu Juan, Liu Liang, Fan Yimin
Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Chemical Engineering, Longpan Road 159, Nanjing 210037, Jiangsu, China.
Int J Biol Macromol. 2023 Apr 30;235:123754. doi: 10.1016/j.ijbiomac.2023.123754. Epub 2023 Feb 21.
There is an increasing concern about developing biobased colloid particles for Pickering stabilization due to the environment-friendliness and health-safety needs. In this study, Pickering emulsions were formed by using TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidized cellulose nanofibers (TOCN) and chitin nanofibers prepared by TEMPO-mediated oxidation (TOChN) or partial deacetylation (DEChN). The physicochemical characterizations of Pickering emulsions demonstrated that the higher cellulose or chitin nanofiber concentrations, surface wettability, and zeta-potential, the higher effectiveness in Pickering stabilization. Specifically, even though DEChN was at a shorter size (with a length of 254 ± 72 nm) as compared to TOCN (with a length of 3050 ± 1832 nm), it showed an excellent stabilization effect on emulsions at the concentration of 0.6 wt% due to its higher affinity to soybean oil (water contact angle of 84.38 ± 0.08°) and large electrostatic repulsion between oil particles. Meanwhile, when the concentration was 0.6 wt%, long TOCN (water contact angle of 43.06 ± 0.08°) formed a three-dimensional network in the aqueous phase, which produced a superstable Pickering emulsion resulting from the limited moving of droplets. These results provided important information on the formulation of Pickering emulsions stabilized by polysaccharide nanofibers with suitable concentration, size and surface wettability.
由于环境友好和健康安全需求，人们对开发用于皮克林稳定化的生物基胶体颗粒越来越关注。在本研究中，通过使用2,2,6,6-四甲基哌啶-1-氧基自由基（TEMPO）介导的氧化纤维素纳米纤维（TOCN）以及通过TEMPO介导的氧化（TOChN）或部分脱乙酰化（DEChN）制备的几丁质纳米纤维来形成皮克林乳液。皮克林乳液的物理化学表征表明，纤维素或几丁质纳米纤维的浓度越高、表面润湿性和zeta电位越高，皮克林稳定化的效果就越好。具体而言，尽管与TOCN（长度为3050±1832nm）相比，DEChN的尺寸较短（长度为254±72nm），但由于其对大豆油具有更高的亲和力（水接触角为84.38±0.08°）以及油滴之间存在较大的静电排斥力，它在浓度为0.6wt%时对乳液表现出优异的稳定效果。同时，当浓度为0.6wt%时，长的TOCN（水接触角为43.06±0.08°）在水相中形成三维网络，由于液滴的移动受限而产生了超稳定的皮克林乳液。这些结果为通过具有合适浓度、尺寸和表面润湿性的多糖纳米纤维稳定化的皮克林乳液的配方提供了重要信息。
