2022-08-18 ペンシルベニア州立大学(PennState)
有機材料をプラットフォームとして、ネオジムのような金属に付着して、それらを取り囲む流体から分離できる高機能マイクロ・ナノ粒子を作る。静電相互作用によって、負に帯電したマイクロ・ナノスケール材料が、正に帯電したネオジム・イオンと結合して、それらを分離する。
実験の準備のために、トマトの皮とコーンコブを粉砕し、木材パルプとコットンペーパーを小さく薄く切って、水に浸ける。そして、これらの材料を制御しながら化学反応させ、微小生成物、ナノ粒子、可溶化したバイオポリマーという3つの異なる機能性材料の分画に崩壊させた。ネオジム溶液に微小生成物やナノ粒子を加えると、分離プロセスが始まり、ネオジム試料を捕獲することができた。
＜関連情報＞
- https://www.psu.edu/news/engineering/story/compost-computer-bio-based-materials-used-salvage-rare-earth-elements/
- https://www.sciencedirect.com/science/article/abs/pii/S1385894722029060#f0040
ネオジム回収のための高機能バイオベースマイクロ・ナノ構造材料 Highly functional bio-based micro- and nano-structured materials for neodymium recovery
Mica L.Pitcher,Breanna Huntington,Juliana Dominick,Amir Sheikhi
Chemical Engineering Journal Available online: 6 June 2022
DOI:https://doi.org/10.1016/j.cej.2022.137418
Highlights
- •A universal method to convert biomass into highly charged products was proposed.
- •Periodate-chlorite oxidation yielded highly carboxylated micro- and nanomaterials.
- •Lignocellulosic nanoparticles had up to 6 mmol of carboxylate per gram.
- •Carboxylated products enabled removal and recovery of neodymium ions from water.
- •This method is a step forward to convert biomass into highly functional materials.
Abstract
One of the main pillars of sustainable development is the preparation of functional materials derived from renewable resources. Nevertheless, facile methods to convert lignocellulosic biomass into value-added, highly functional materials remain limited. Here, we evaluate the potential of an acid-free method to convert a variety of lignocellulosic biomass into highly charged micro- and nano-structured materials. We show how the sequential oxidation of delignified (e.g., softwood pulp and cotton) or untreated (e.g., corncob and tomato peel) lignocellulosic sources yield three distinct products, including biopolymeric nanoparticles (BNP), solubilized biopolymers (SB), and microproducts (MP), bearing up to 6 mmol of carboxylate groups per gram, which is up to ∼ 500 % beyond the theoretical charge content of conventional cellulose nanocrystals (CNC). The main difference among the products was the type of nanoparticles: delignified sources yielded hairy cellulose nanocrystals, whereas lignin nanoparticles were formed from the untreated sources. As a proof-of-concept for the applications of these materials, we show that carboxylated cotton microproducts remove ∼ 92.5 mg of neodymium ions per gram from a dilute solution in less than 5 min and recover approximately 64 % of it via pH adjustment. This work may provide new opportunities for the conversion of a wide array of lignocellulosic biomass to highly functional biocolloids with extremely high charge density for advanced sustainable applications.
