Cellulosic polymer colloids, polymers and polyelectrolytes

纤维素聚合物胶体、聚合物和聚电解质

• 批准号: RGPIN-2018-05781
• 负责人: VanDeVen, Theodorus
• 金额: $ 3.5万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=689647
• 关键词: Cellulosic; polymer; colloids; polymers; polyelectrolytes

An important contribution to the emerging bioeconomy is the conversion of biomass to useful products in environmentally friendly processes. About 5 years ago, we made a fascinating discovery. We discovered a novel type of nanocellulose (now called hairy nanocellulose, HNC), very different from the conventional cellulose nanocrystals (CNC) and cellulose nanofibrils (CNF). The novel particle consists of a rod-shaped colloidal core and contains many polymeric or polyelectrolyte chains (the “hairs”). HNC particles belong to the class of polymer colloids. They can be produced by an aqueous process from delignified wood fibers (cellulose fibers) with a yield of about 50%. The other 50% consists of water-soluble cellulose derivatives. The research proposed here will address properties and applications of HNC and properties of the water soluble cellulosics and derivatives thereof. We propose to organize the research in 7 topics. In topic 1, “Characterization of HNC”, we will attempt imaging the hairs with three different techniques: (i) labeling the hairs with gold nanoparticles (AuNP), followed by TEM; (ii) imaging the hairs by AFM using chemically modified tips; (iii) by Stochastic Optical Reconstruction Microscopy (STORM). Topic 2 deals with HNC produced from CNC, and the liquid crystalline properties of right and left handed CNC. Topic 3 addresses the aggregation of trimmed HNC. We have shown that one can crosslink carboxylated crew cut HNC with a diamine (via bioconjugation or click chemistry), which results in end-to-end aggregation, since almost all the charges of HNC are located in the short hairs at both ends. It should also be possible to make long slender nanofibrils by mixing positively and negatively charged crew cut HNC, resulting in long fibrils in which the two types of HNC alternate. Topics 4 and 4 deal with antiscaling properties of HNC and antifouling membranes of polymer/HNC composites, to be measured by chronoamperometry. Finally topics 6 and 7 deal with the properties of cellulosic water-soluble polymers and polyelectrolyes respectively. Specifically, we propose to study cellulose derivatives with dialdehyde groups on the C2-C3 carbons of cellulose, with a degree of oxidation (DO) of about 1. We refer to these polymers as dialdehyde modified cellulose (DAMC), to distinguish them from dialdehyde cellulose (DAC), for which DO = 2. We propose to study the properties of DAMC and DAC, such as molecular weight, polydispersity in molecular weight and density of aldehyde groups, persistence length, Flory-Huggins - parameter (or polymer-solvent interaction parameter, etc.), as well as its long-time stability. Some of the techniques used will be GPC (gel permeation chromatography, static light scattering and osmotic pressure measurements. We will attach photoswitchable molecules to DAMC and image the polymeric chains with STORM.

对新兴生物经济的重要贡献是将生物量转化为环保过程中有用的产品。大约5年前，我们做出了一个有趣的发现。我们发现了一种新型的纳米纤维素（现在称为Haincolose，HNC），与常规的纤维素纳米晶体（CNC）和纤维素纳米纤维（CNF）截然不同。新型粒子由棒状胶体芯组成，并包含许多聚合物或聚电解质链（“头发”）。 HNC颗粒属于聚合物胶体类别。它们可以由发达的木纤维（纤维素纤维）的水性过程产生，产量约为50％。其他50％由水溶性纤维素衍生物组成。此处提出的研究将解决HNC的特性和应用以及其固体纤维素及其衍生物的特性。我们建议在7个主题中组织研究。在主题1，“ HNC的特征”中，我们将尝试用三种不同的技术对头发进行成像：（i）用金纳米颗粒（AUNP）标记头发，然后是TEM； （ii）使用化学修饰的尖端对AFM进行成像； （iii）通过随机光学重建显微镜（Storm）。主题2涉及由CNC产生的HNC，以及左右与CNC的液晶特性。主题3解决了修剪的HNC的聚合。我们已经表明，可以将羧化的乘员乘以二氨酸（通过生物缀合或点击化学）切割HNC，这会导致端到端聚集，因为HNC的几乎所有电荷都位于两端的短发中。还应该通过积极和负电荷的船员切割HNC来制作长长的纳米纤维，从而导致长期的HNC替代品。主题4和4涉及HNC和聚合物/HNC组合物的防染色机制的抗验性能，可通过计时仪测量。最后，主题6和7分别介绍了纤维素水溶性聚合物和聚电解质的性质。具体而言，我们建议在纤维素的C2-C3碳上研究纤维素衍生物，其氧化程度（DO）约为1。分子量，分子量的多分散性和醛基的密度，持久性长度，flory-huggins-参数（或聚合物 - 溶剂相互作用参数等）以及其长时间稳定性。使用的某些技术将是GPC（凝胶渗透色谱，静态光散射和渗透压测量。我们将将可拍照的分子连接到DAMC上，并用风暴将聚合物链成像。