Innventia AB, Box 5604, SE-11486 Stockholm, Sweden.
Nanoscale. 2012 Oct 21;4(20):6622-8. doi: 10.1039/c2nr31726e.
A novel, technically and economically benign procedure to combine vermiculite nanoplatelets with nanocellulose fibre dispersions into functional biohybrid films is presented. Nanocellulose fibres of 20 nm diameters and several micrometers in length are mixed with high aspect ratio exfoliated vermiculite nanoplatelets through high-pressure homogenization. The resulting hybrid films obtained after solvent evaporation are stiff (tensile modulus of 17.3 GPa), strong (strength up to 257 MPa), and transparent. Scanning electron microscopy (SEM) shows that the hybrid films consist of stratified nacre-like layers with a homogenous distribution of nanoplatelets within the nanocellulose matrix. The oxygen barrier properties of the biohybrid films outperform commercial packaging materials and pure nanocellulose films showing an oxygen permeability of 0.07 cm(3) μm m(-2) d(-1) kPa(-1) at 50% relative humidity. The oxygen permeability of the hybrid films can be tuned by adjusting the composition of the films. Furthermore, the water vapor barrier properties of the biohybrid films were also significantly improved by the addition of nanoclay. The unique combination of excellent oxygen barrier behavior and optical transparency suggests the potential of these biohybrid materials as an alternative in flexible packaging of oxygen sensitive devices such as thin-film transistors or organic light-emitting diode displays, gas storage applications and as barrier coatings/laminations in large volume packaging applications.
本文提出了一种新颖的、技术和经济上良性的方法，可将蛭石纳米片与纳米纤维素纤维分散体结合到功能性生物杂化薄膜中。20nm 直径和数微米长的纳米纤维素纤维通过高压匀浆与高纵横比的剥离蛭石纳米片混合。溶剂蒸发后得到的杂化薄膜具有刚性（拉伸模量为 17.3GPa）、高强度（高达 257MPa）和透明性。扫描电子显微镜（SEM）表明，杂化薄膜由分层的珍珠层状层组成，纳米片在纳米纤维素基质中均匀分布。生物杂化薄膜的氧气阻隔性能优于商业包装材料和纯纳米纤维素薄膜，在 50%相对湿度下的氧气透过率为 0.07cm3μm m-2d-1kPa-1。通过调整薄膜的组成，可以调节杂化薄膜的氧气透过率。此外，通过添加纳米粘土，还可以显著提高生物杂化薄膜的水蒸气阻隔性能。优异的氧气阻隔性能和光学透明度的独特结合表明，这些生物杂化材料有可能替代对氧气敏感的器件（如薄膜晶体管或有机发光二极管显示器）的柔性包装、气体储存应用以及在大容量包装应用中的阻隔涂层/层压材料。
