目标:引人注目的是,牛皮纸木质素纳米颗粒(KLNP)可以在各种应用中替代污染纳米颗粒。合成KLNP的一种有吸引力的方法是溶剂转移。我们假设,通过详细了解溶剂性质和工艺参数的影响,人们可以获得有关木质素纳米颗粒形成过程的新的基础和技术信息。
方法:基于木质素的汉森溶解度参数,选择DMSO和THF为最佳溶剂。木质素浓度等四个合成参数,(反溶剂)水量,温度,和搅拌速度用于研究尺寸,多分散指数(PDI),形态以及热,KLNPsDMSO和KLNPsTHF的机械和光学性能。
结果:KLNPsTHF遵循众所周知的成核和生长(NG)机制,产生球形KLNP(43±12nm:0.20PDI)。令人惊讶的是,KLNPsDMSO遵循一种独特的机制,类似于亚峰分解(SD),产生罕见的双连续至球形KLNP(17±8nm:0.20PDI)。值得注意的是,我们表明,KLNP机制的差异调节了它们的内在性质,如玻璃化转变温度(Tg),比表面积(SSA),弹性模量(EM)和光学性能。除了新的机制,我们的合成导致可重复的超小KLNP,具有优异的%产率。这些发现在高性能纳米复合材料中具有广泛的意义。
OBJECTIVE: Strikingly, Kraft lignin nanoparticles (KLNPs) can substitute polluting nanoparticles in diverse applications. An attractive method for synthesizing KLNPs is Solvent shifting. We hypothesized that by a detailed understanding of the solvent properties and influence of the process parameters, one could derive new fundamental and technical information about the lignin nanoparticle formation process.
METHODS: DMSO and THF were chosen best solvents based on the Hansen solubility parameter of lignin. The four synthesis parameters such as lignin concentration, (anti-solvent) water volume, temperature, and stirring speed were used to investigate the size, polydispersity index (PDI), morphology as well as the thermal, mechanical and optical properties of KLNPsDMSO & KLNPsTHF.
RESULTS: KLNPsTHF follows the well-known nucleation and growth (NG) mechanism, resulting in spherical KLNPs (43 ± 12 nm: 0.20 PDI). Surprisingly, KLNPsDMSO follows a unique mechanism resembling spinodal decomposition (SD), which generates rare bicontinuous-to-spherical KLNPs (17 ± 8 nm: 0.20 PDI). Remarkably, we show that the difference in the KLNPs mechanism modulates their intrinsic properties, such as glass transition temperature (Tg), specific surface area (SSA), elastic modulus (EM) and optical properties. Beyond the new mechanism, our synthesis resulted in reproducible ultra-small KLNPs with an excellent % yield. Such findings have vast implications in high-performance nanocomposites.