Upcycling of Waste Hop Stems into Cellulose Nanofibers: Isolation and Structural Characterization
Upcycling of Waste Hop Stems into Cellulose Nanofibers: Isolation and Structural Characterization
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DOI：
10.1021/acsagscitech.1c00041
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发表时间：
2021-08-16
期刊：
影响因子：
--
通讯作者：
Kawamura, Izuru
中科院分区：
文献类型：
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作者：
Kanai, Noriko;Nishimura, Kosuke;Kawamura, Izuru
啤酒花(Humulus Lupulus)是为了收获雌花而种植的，这种花给啤酒带来了浓郁的味道、芳香和苦味。然而，工厂的其余部分被焚烧或作为农用工业废物填埋。这项工作对含有44%纤维素的啤酒花茎(HS)进行了回收，并证明了它们适合作为分离纤维素纳米纤维(CNF)的原料。用WISE法脱除木质素和半纤维素，再进行碱处理。2，2，6，6-四甲基哌啶-1-氧基自由基氧化使未处理和处理的HS中的CNF纤化。从原子力显微镜可以推断出均匀的高度分布，经过处理和未处理的HS来源的CNF的中位数类似于2 nm。固体核磁共振和X-射线衍射仪的表征表明，尽管有少量的三酰甘油和一水合草酸钙存在，但预处理提高了碳纳米纤维的纯度和结晶度。两个CNF样品在255-260℃和300℃下表现出相似的两步热降解，尽管处理后的CNF产生的残炭较少。
Hop (Humulus lupulus) is cultivated to harvest female flowers that lend a deep flavor, aroma, and bitter taste to beer. However, the rest of the plant is burned or land filled as agro-industrial waste. This work upcycles hop stems (HS), which contain 44% cellulose, and demonstrates their suitability as raw materials for the isolation of cellulose nanofibers (CNFs). The Wise method followed by alkaline pretreatment removed lignin and hemicellulose. 2,2,6,6-Tetramethylpiperidine-1-oxyl radical-mediated oxidation fibrillated CNFs from pretreated and non-pretreated HS. A uniform height distribution was inferred from atomic force microscopy, with a median of similar to 2 nm for pretreated and non-pretreated HS-derived CNFs. Solid-state nuclear magnetic resonance and X-ray diffraction characterizations indicated that the pretreatment enhanced the purity and crystallinity of the CNFs, though traces of triacylglycerols and calcium oxalate monohydrate remained. The two CNF samples exhibited similar two-step thermal degradation at 255-260 and 300 degrees C, though less char residue was produced by the pretreated CNFs.