Myelin Figures: Non-equilibrium organization of amphiphiles induced by hydration

髓磷脂图：水合诱导的两亲物的非平衡组织

• 批准号: 2104123
• 负责人: Atul Parikh
• 金额: $ 49.14万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2104123&HistoricalAwards=false
• 关键词: Myelin; Figures; Non; equilibrium; organization

Non-Technical Abstract: Oil and water do not mix. But many ordinary soaps and detergent negate this proverbial expression by allowing the two substances to mix. Called surfactants, these soft and fragile materials interact with water (or oil) in complex, subtle, and nuanced manners. Their dissolution in water is often accompanied by the formation of unusual structures that extend far beyond the sizes of molecules producing a dynamic mosaic that characterize the surfactant-laden aqueous phase. One such example is the formation of a class of finger-like cylindrical protrusions called myelin figures, tens of micrometers in diameters and hundreds of micrometers in length, which appear when a dry mass of surfactant meets water. This project involves controlled laboratory experiments to study their formation, direct their growth, and exploit their morphologies to produce novel nanomaterials. The findings of the project should benefit many areas of applications, including food, cosmetics, soap, and dispersion technologies. The project includes the training and participation of a graduate student and a post-doc in the scientific process. It also engages undergraduate students and underrepresented groups in STEM through the Vertically-Integrated Program, which offers Science & Society credits and opportunities for laboratory research over multiple years on a single, consolidated project.Technical Abstract: The equilibration of complex fluids is often accompanied by unusual instabilities as they progress toward equilibrium. This is perhaps best exemplified by myelinic instabilities, which emerge when an insoluble surfactant meets water. The individual myelins ¬– cylindrical smectic liquid crystals tens of micrometers in diameter and hundreds of micrometers in length – grow sinuously, by a two-dimensional reptation-like motion, which tightly juxtapose with their neighbors; elongate, cooperatively; and, often fold morphologically, into symmetry-breaking helical shapes. This project seeks to understand their formation mechanisms, control their spatial organization, investigate their responsiveness to environmental perturbations, and exploit their nanometer scale confinements to template synthesis of nanostructures. It experimentally tests the hypothesis that the intrinsically non-equilibrium process of amphiphilic hydration can be controllably tuned to lift equilibrium constraints, dial-in structural instabilities, and kinetically trap long-lived metastable states within the free energy landscape that characterizes the hydration process. It also seeks to exploit myelin figures as self-organizing dynamic templates to synthesize nanoscale materials into hierarchical, extended, and complex superlattices. Using a combination of microscopy based quantitative measurements, the planned research activities include(1) develop methods to control the spatial organization of myelin figures (taming the chaos); (2) characterizing phase-separating mixtures of amphiphiles within myelin morphologies (introducing chemical diversity); (3) accessing higher-order, symmetric breaking organization of myelin figures by coupling physical-chemical stress from their local microenvironment (shape-shifting myelins); and (4) templating synthesis of nanomaterials by exploiting myelinic confinement (templated nanosynthesis). The effort should yield new insights into non-equilibrium routes for controlling supramolecular organization and novel approaches for synthesis-with-design.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术摘要：油和水不混合。但是，许多普通的肥皂，并通过允许两种物质混合来确定这种可靠的表达。这些柔软和脆弱的材料称为表面优美，以复杂，微妙和细微的方式与水（或油）相互作用。它们在水中的溶解通常伴随着不寻常的结构的形成，这些结构远远超出了产生动态镶嵌物的分子大小的范围，该动态镶嵌物是表面活性剂水相的特征。这样的例子是形成一类手指样圆柱蛋白，称为髓磷脂图，直径数十微米，长度为数百微米，当大量的基础质量遇到水时，会出现。该项目涉及受控的实验室实验，以研究其形成，指导其生长并利用其形态来产生新型纳米材料。该项目的发现应受益于许多应用领域，包括食品，化妆品，肥皂和分散技术。该项目包括研究生的培训和参与，以及在科学过程中进行研究后的培训和参与。它还通过垂直集成的计划与STEM的本科生和代表性不足的群体互动，该计划在一个单个合并的项目上为多年来提供了科学与社会的学分和实验室研究的机会。技术摘要：复杂流体的平衡通常是通过在平衡方面取得了不寻常的稳定性来实现的。这很可能是用髓质不稳定性来体现的，当不溶性表面活性剂遇到水时，它会出现。单个髓素 - 圆柱形的Smictic液体晶体的直径数十个微米和数百微米的长度 - 通过二维繁殖样运动，弯曲地生长，它们与邻居紧密息息；拉长，合作；而且，通常从形态上折叠成对称性的螺旋形状。该项目旨在了解其形成机制，控制其空间组织，研究其对环境扰动的反应，并利用其纳米量表仅限于纳米结构的模板合成。它通过实验检验了以下假设：可以控制两亲水合的本质非平衡过程，以提高平衡约束，拨号结构不稳定性以及动力学捕获长期捕获的自由能在自由能环境内的固定状态。它还试图作为自组织动态模板探索髓磷脂数字，以将纳米级材料合成为层次，扩展和复杂的超晶格。使用基于显微镜的定量测量的组合，计划的研究活动包括（1）开发控制髓磷脂数字的空间组织（驯服混乱）的方法； （2）表征髓磷脂形态中两亲体的相分离混合物（引入化学多样性）； （3）通过从其局部微环境（形状转化髓磷脂）耦合物理化学应力，从而访问髓磷脂图的高阶，对称破坏组织； （4）通过利用髓磷脂约束（模板）纳米合成来模板合成纳米材料。这项努力应为控制超分子组织的非均衡途径提供新的见解，并为合成设计的新颖方法提供新的方法。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响审查标准通过评估来评估的。

项目成果

Nonequilibrium Self-Organization of Lipids into Hierarchically Ordered and Compositionally Graded Cylindrical Smectics

• DOI: 10.1021/acs.langmuir.1c02576
• 发表时间: 2022-01-12
• 期刊: LANGMUIR
• 影响因子: 3.9
• 作者: Ho, James C. S.;Su, Wan-Chih;Liedberg, Bo
• 通讯作者: Liedberg, Bo