Abstract:
This work describes the chemical and structural characterization of a lignin-rich residue from the bioethanol production of olive stones and its use for nanostructures development by electrospinning and castor oil structuring. The olive stones were treated by sequential acid/steam explosion pretreatment, further pre-saccharification using a hydrolytic enzyme, and simultaneous saccharification and fermentation (PSSF). The chemical composition of olive stone lignin-rich residue (OSL) was evaluated by standard analytical methods, showing a high lignin content (81.3 %). Moreover, the structural properties were determined by Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and size exclusion chromatography. OSL showed a predominance of β-β\' resinol, followed by β-O-4\' alkyl aryl ethers and β-5\' phenylcoumaran substructures, high molecular weight, and low S/G ratio. Subsequently, electrospun nanostructures were obtained from solutions containing 20 wt% OSL and cellulose triacetate with variable weight ratios in N, N-Dimethylformamide/Acetone blends and characterized by scanning electron microscopy. Their morphologies were highly dependent on the rheological properties of polymeric solutions. Gel-like dispersions can be obtained by dispersing the electrospun OSL/CT bead nanofibers and uniform nanofiber mats in castor oil. The rheological properties were influenced by the membrane concentration and the OSL:CT weight ratio, as well as the morphology of the electrospun nanostructures.
摘要:
这项工作描述了来自橄榄石生物乙醇生产的富含木质素的残留物的化学和结构表征,以及通过静电纺丝和蓖麻油结构化将其用于纳米结构开发的用途。橄榄石通过连续的酸/蒸汽爆炸预处理处理,使用水解酶进一步预糖化,和同时糖化和发酵(PSSF)。通过标准分析方法评估了橄榄石富含木质素的残留物(OSL)的化学成分,表现出较高的木质素含量(81.3%)。此外,通过傅里叶变换红外光谱测定结构性质,核磁共振,和尺寸排阻色谱法。OSL以β-β树脂醇为主,其次是β-O-4烷基芳基醚和β-5苯基香豆素亚结构,高分子量,和低S/G比。随后,从含有20wt%OSL和三醋酸纤维素的溶液中获得电纺纳米结构,N-二甲基甲酰胺/丙酮共混物并通过扫描电子显微镜表征。它们的形态高度依赖于聚合物溶液的流变性质。凝胶状分散体可以通过将电纺OSL/CT珠纳米纤维和均匀的纳米纤维垫分散在蓖麻油中来获得。流变特性受膜浓度和OSL:CT重量比的影响,以及电纺纳米结构的形态。