Sharma Deepika, Harte Federico M, Ziegler Gregory R
Department of Food Science, The Pennsylvania State University, University Park, PA 16802, USA.
Department of Food Science, The Pennsylvania State University, University Park, PA 16802, USA.
J Colloid Interface Sci. 2025 Sep;693:137601. doi: 10.1016/j.jcis.2025.137601. Epub 2025 Apr 14.
Nanofibers were electrospun (20 kV, 6 mL/h, 10 cm, 8 h) from a phase-separated mixture of hydroxypropyl methylcellulose (HPMC) and molecularly dispersed casein. Associative phase separation resulted in a dope comprising a gel-like coacervate phase dispersed in a casein solution with a third phase comprising casein aggregates. Beadless fibers of 535 nm average diameter, a maximum specific surface area of 3.3 m/g, and maxima in Young's modulus and tensile strength were spun from a dope containing 1.5 % w/v HPMC and 18.5 % w/v acid casein in 50 % v/v aqueous ethanol at pH 10 demonstrating a minimum in surface tension. Classic spindle-shaped beads resulting from Rayleigh instability were observed at lower HPMC concentrations as were thickened, irregular fibers likely resulting from the unique phase behavior at higher HPMC levels. At 100 % relative humidity, the fiber mats readily adsorbed moisture, causing their transformation into clear films. Reinforcement with HPMC produced casein-rich nanofibers with improved mechanical strength and potential utility in food, biomedical, or cosmetic applications.
纳米纤维是由羟丙基甲基纤维素（HPMC）和分子分散的酪蛋白的相分离混合物通过静电纺丝法制备而成（20千伏，6毫升/小时，10厘米，8小时）。缔合相分离产生了一种纺丝原液，该原液包含分散在酪蛋白溶液中的凝胶状凝聚相，以及包含酪蛋白聚集体的第三相。从含有1.5% w/v HPMC和18.5% w/v酸性酪蛋白的纺丝原液中，在pH值为10的50% v/v乙醇水溶液中纺出平均直径为535纳米、最大比表面积为3.3平方米/克、杨氏模量和拉伸强度达到最大值的无珠纤维，其表面张力最小。在较低的HPMC浓度下观察到由瑞利不稳定性产生的经典纺锤形珠子，在较高的HPMC水平下则观察到可能由独特相行为导致的变粗、不规则纤维。在100%相对湿度下，纤维垫很容易吸附水分，导致它们转变成透明薄膜。用HPMC增强后产生了富含酪蛋白的纳米纤维，其机械强度得到提高，在食品、生物医学或化妆品应用中具有潜在用途。
