Fibre and Polymer Technology, Royal Institute of Technology (KTH), Stockholm, Sweden.
Biomacromolecules. 2012 Aug 13;13(8):2570-7. doi: 10.1021/bm300821d. Epub 2012 Jul 31.
Barrier performance and retrostructural modeling of the macromolecular components demonstrate new design principles for film formulations based on renewable wood hydrolysates. Hardwood hydrolysates, which contain a fair share of lignin coexisting with poly- and oligosaccharides, offer excellent oxygen-barrier performance. A Hansen solubility parameter (HSP) model has been developed to convert the complex hydrolysate structural compositions into relevant matrix oxygen-permeability data allowing a systematic prediction of how the biomass should be formulated to generate an efficient barrier. HSP modeling suggests that the molecular packing ability plays a key role in the barrier performance. The actual size and distribution of free volume holes in the matrices were quantified in the subnanometer scale with Positron annihilation lifetime spectroscopy (PALS) verifying the affinity-driven assembly of macromolecular segments in a densely packed morphology and regulating the diffusion of small permeants through the matrix. The model is general and can be adapted to determine the macromolecular affinities of any hydrolysate biomass based on chemical composition.
高分子成分的阻隔性能和反结构建模为基于可再生木材水解物的薄膜配方提供了新的设计原则。硬木水解物含有相当比例的木质素，与聚糖类和寡糖类共存，具有优异的氧气阻隔性能。已经开发出一种 Hansen 溶解度参数（HSP）模型，可将复杂的水解物结构成分转换为相关的基质氧气透过率数据，从而可以系统地预测生物质应如何进行配方设计以产生有效的阻隔性能。HSP 模型表明，分子堆积能力在阻隔性能中起着关键作用。采用正电子湮没寿命谱（PALS）在亚纳米尺度上量化了基质中自由体积孔的实际大小和分布，证实了大分子段在致密堆积形态下的亲和驱动组装，并调节了小分子渗透物通过基质的扩散。该模型具有通用性，可以根据化学成分确定任何水解生物质的大分子亲和力。
