特殊浸润性表面构建及其抑制酸奶黏附的研究

Fabrication of Special Wettability Surface and Application in Inhibition of Yogurt Adhesion

目的构建一种能够抑制酸奶黏附现象的特殊浸润性表面,探索特殊浸润表面的结构、组成及性能。方法以棕榈蜡、二氧化硅和羧甲基纤维素钠为原料,通过喷涂法在聚苯乙烯片材上构建特殊浸润性表面。结果棕榈蜡添加量为3 g,二氧化硅为0.9 g,两者共溶于100 mL无水乙醇,将0.6 g羧甲基纤维素钠溶于100 mL去离子水时,2种溶液共混(V_(乙醇溶液)∶V_(水溶液)=2∶1)在聚苯乙烯片材表面进行喷涂,并于75℃烘干30 min,得到特殊浸润性表面。所构建的特殊浸润性表面具有典型的微纳结构,酸奶在其表面的接触角为(141.32±5.43)°,滚动角为(7.51±2.86)°。耐碱、耐盐试验表明,特殊浸润性涂层在浸泡24 h后,酸奶在其表面的接触角分别为(132.00±5.75)°和(130.18±6.09)°,与原始特殊浸润性表面相比未发生显著性下降(P>0.05)。此外,甲基蓝和邻苯二酚紫粉末的残留结果表明所构建的表面自清洁性能良好。酸奶在具有特殊浸润性表面的聚苯乙烯片材上的残留量为(3.77±1.99)%,显著低于无特殊浸润性表面的聚苯乙烯片材(15.12±2.77)%(P<0.05)。结论该特殊浸润性表面具有良好的化学稳定性、自清洁性和不黏性,可有效减少酸奶资源的浪费,也为液态黏性流体食品的包装设计提供理论依据。

Plenty of residual yogurt is always adhere to the inner face of the package after daily drink, causing severe waste of food resource. Thus, a special wetted surface was fabricated to inhibit the adhesion phenomenon of yogurt, which was used to reduce the residual amount of yogurt.In this study, the carnauba wax, silica and sodium carboxymethyl cellulose were used as the original materials which could be developed a hydryphobic surface. 3 g carnauba wax and 0.9 g silica were dissolved in 100 mL absolute ethyl alcohol and was taken a water bathe at 80 ℃ for 30 min in a magnetic stirring equipment. While 0.6 g sodium carboxymethyl cellulose was dissolved in 100 mL deionized water at 75 ℃ for 30 min. Afterwards, the ethyl alcohol solution and the water solution were mixed together with a volume ratio of 2:1 and spayed on the polystyrene sheets to form a special wettable surface in 75 ℃ for 30 min. Then, the special wettability surface was characterized comprehensively. A scanning electron microscope and a Fourier infrared spectrometer were utilized to analyze the morphology and the constitute of the special wetting surface. At the same time, the chemical stability test, self-cleaning property test, anti-pollution test, and inadhesion test were all performed verify the applicability of the special wetted surface. Lastly, the residual amount of yogurt was detected to verify the applicability of the special wettability surface.The typical micro-nano structure could be observed on the special wettability surface. Meanwhile, carnauba wax, silica and sodium carboxymethyl cellulose could be integrally fused to constitute the special wetted surfaces, which could be concluded from the Fourier infrared spectroscopy curves. The contact Angle of water on the special wetted surface was(131.34±3.61)°, but water could not be rolled freely probably due to the existence of hydrogen bonds between the sodium carboxymethyl cellulose and water. Besides, The contact Angle, rolling Angle of yogurt on the wettability surface were(141.32±5.43)° and(7.51±2.86)°,respectively, indicating great inhibition adherence of the yogurt on the special wetted surface. Alkali resistance and salt resistance tests showed that the contact angles of yogurt on the special wettability surfaces were(132.00±5.75)° and(130.18±6.09)° after soaking for 24 h, respectively, without significant decrease compared to the original wettability surface(141.32±5.43)°(P<0.05). However, after acid resistance test, the contact angle of yogurt on the special wettability surface decreased dramatically to(112.39±8.84)°(P<0.05). It could be inferred that the acid solution contained a lot of H+ which could easily bind to the sodium carboxymethyl cellulose, damaging the integrity of the special wettability surface. In addition, the residual results of methyl blue powder and solution showed that the fabricated surface had good self-cleaning performance. And the residual amount of yogurt was significantly decreased from(15.12±2.77)% to(3.77±1.99)% compared the pristine polystyrene sheets with the coated sheets(P<0.05). Although yogurt is a complicated liquid system which contained nutrient substances such as lactose, lipid, protein and lactic acid, the special wettability surface could be served as an efficient package material to reduce the adhesion of yogurt significantly.Totally, the special wettable surface has good chemical stability, self-cleaning and non-viscosity, which can effectively reduce the waste of yoghurt resources, and also provides a theoretical basis for the packaging design of liquid viscous fluid food.