Fabrication And Evaluation Of Nanocellulose Masks And Their Functionalized Products

Bacterial Cellulose, BC, synthesized from Gluconacetobacter xylinum, is considered as a natural polymer material which has biocompatibility as well as biodegradability. Because of its unique physical and chemical properties, such as high water holding capacity, high purity and fine wet state flexibility, BC has been successfully commercialized in various areas such as food manufacturing, paper making and wound dressing. Recently, BC based facial masks have been emerged from comsmetics markets of Europe, America and China Taiwan, and have been attracting customers attention. BC has great potential value in cosmetic raw materials due to its whole bio process. In this paper, we focus on several bottlenecks like poor fermentation techniques, limited applications and low products added value, and try to establish a bio-nanocellulose facial masks engineering and manufacturing system. Based on fermentation structure modification and in situ combination, we try to develope bio-nanocellulose functionalized facial masks serial products, in order to promote the differentiation degree of Chinese BC based products as well as broaden application area, and further provide theoretical evidence for Chinese BC manufacturing.The detailed contents are listed as follows:1. Based on lab level BC manufacturing system, unmodified BC masks have been prepared using static fermentation. We use Scanning electronic microscope, Elemental analysis, Fourier transmittance infra-red spectrum, X-ray diffraction, Comfort value test, Water hoding capacity and Water vapor transmission rate to evaluate the physical and chemical properties of unmodified BC masks, and compared with commercialized non-woven masks and commercialized biocellulose masks (Genifique, Lancome(?) and Melasleep Whitening, For be loved one(?)). The results indicated that the average nanocellulose fiber diameter is48.6±13.4nm, which is1/306of that of non-woven masks and similar to that of commercialized biocellulose masks. The wet state mechanical properties of unmodified BC masks (Tensile strength1.13±0.1MPa, Elastic modulus6.03±0.56MPa) are2times and4times higher than non-woven masks, respectively, slightly higher than that of commercialized biocellulose masks.90°peeling strength (0.88±0.05N/m) is5.5times higher than non-woven masks and similar to that of commercialized biocellulose masks. Water hoding capacity under3000g (133g water/g cellulose) is665times higher than non-woven masks. Water vapor transmission rate is8482g-m-2-24h-1, which is3626g·m-2·24h-1lower than that of non-woven masks. The unmodified BC masks can rehydrate to saturation static only when the water holding rate is no less than40%.HA-BC mask were prepared by in situ modification. Compared with unmodified BC mask, HA-BC mask shows similar wet state flexibility and conformability while the crystallinity index reduced from92.97%to90.89%and shows better softness. HA-BC shows double-stage morphology with dense upper layer and porous lower layer which is similar to human skin, and the long-term moisturizing ability is higher than that of unmodified BC. The water vapor transmission rate of HA-BC is5640g-m-2-24h-1, which is2842g·m-2·24h-1lower than the unmodified BC. In order to develop nanocellulose based functionalized facile masks serial products, we choose extracts from herba agrimoniae, white papaya and bletilla striata and stabilized them into nanocellulose network via physical absorbtion and H-bonding coupling. The test results indicate that the removing rate of DPPH radical after adding these herbal additives into the HA-BC masks are91.88%、91.77%and74.15%respectively. The suppress ability against tyrosinase are15.04%、14.29%and9.82%respectively, and the long-term moisturizing rate within24h are15.12±0.47、13.52±0.53and13.7±0.44respectively.Based on1and2, the viscosity of essence is inversely proportional to absorption volume when unmodified BC mask is soaked in essence. The viscosity of essence for unmodified BC masks should be less than300mpa·s and the viscosity of essence for HA-BC masks should be less than673mpa·s. Based on the established fermentation manufacturing system, in situ modification techniques and the dynamic parameters of in situ combination hydro-balance system, we try to establish a new nanocellulose functionalized facial masks manufacturing system of industrial scale including manufacturing process, products standards and systematic testing methods, and provide the large scale manufacturing of nanocellulose masks in our country with some theoretical evidences.