Abstract:
Control over particle size and shape heterogeneity is highly relevant to the design of photonic coatings and supracolloidal assemblies. Most developments in the area have relied on mineral and petroleum-derived polymers that achieve well-defined chemical and dimensional characteristics. Unfortunately, it is challenging to attain such control when considering renewable nanoparticles. Herein, a pathway toward selectable biobased particle size and physicochemical profiles is proposed. Specifically, lignin is fractionated, a widely available heterogeneous polymer that can be dissolved in aqueous solution, to obtain a variety of monodispersed particle fractions. A two-stage cascade and density gradient centrifugation that relieves the need for solvent pre-extraction or other pretreatments but achieves particle bins of uniform size (~60 to 860 nm and polydispersity, PDI<0.06, dynamic light scattering) along with characteristic surface chemical features is introduced. It is found that the properties and associated colloidal behavior of the particles are suitably classified in distinctive size populations, namely, i) nanoscale (50-100 nm), ii) photonic (100-300 nm) and iii) near-micron (300-1000 nm). The strong correlation that exists between size and physicochemical characteristics (molar mass, surface charge, bonding and functional groups, among others) is introduced as a powerful pathway to identify nanotechnological uses that benefit from the functionality and cost-effectiveness of biogenic particles.
摘要:
对颗粒尺寸和形状异质性的控制与光子涂层和超球形组件的设计高度相关。该领域的大多数发展都依赖于矿物和石油衍生的聚合物,这些聚合物实现了明确的化学和尺寸特性。不幸的是,当考虑可再生纳米颗粒时,实现这种控制是具有挑战性的。在这里,提出了一种可选择的生物基粒径和物理化学特征的途径。具体来说,木质素被分馏,一种广泛可用的非均相聚合物,可以溶解在水溶液中,以获得各种单分散的颗粒部分。两级级联和密度梯度离心,可以减轻对溶剂预萃取或其他预处理的需求,但可以实现尺寸均匀的颗粒箱(〜60至860nm和多分散性,PDI<0.06,动态光散射)以及特征性的表面化学特征。发现颗粒的性质和相关的胶体行为被适当地分类为独特的大小群体,即,i)纳米级(50-100nm),ii)光子(100-300nm)和iii)近微米(300-1000nm)。大小和物理化学特性(摩尔质量,表面电荷,键合和官能团,除其他外)被引入作为识别纳米技术用途的强大途径,这些用途受益于生物颗粒的功能和成本效益。