在微凝颗粒的干燥模式中,基板温度驱动的微结构转变
Sanjib Majumder1,2, Madivala G Basavaraj1,2, Dillip K Satapathy1,3,2
1Soft Materials Laboratory, Department of Physics, IIT Madras, Chennai, Tamil Nadu 600036, India.
Langmuir : the ACS journal of surfaces and colloids
|February 24, 2026
概括
聚N-异烯胺 (PNIPAM) 微凝在流体接口上形成有序的单层,使合膜制造成为可能. 它们对温度敏感的行为决定了复杂的沉积模式,提供了可调节的材料特性.
科学领域:
- 软物质物理学 软物质物理学
- 体科学是关于体的科学.
- 材料科学是一种材料科学.
背景情况:
- 聚N-异烯胺) (PNIPAM) 微凝是具有可调节胀行为的刺激反应性合体.
- 与散装相比,微凝在流体-流体接口上表现出不同的动力学,经历平坦化并形成有序的单层.
- 这种界面行为为制造合膜和图案结构提供了一条路径.
研究的目的:
- 研究PNIPAM微凝在滴干燥过程中的自我组装和沉积模式.
- 探索温度和初始微凝度对产生的沉积物形态的影响.
- 了解热调节接口行为在指导微凝自组装中的作用.
主要方法:
- 在受控温度下在水友基板上干燥含有PNIPAM微凝的状水滴.
- 在现场监测使用视频显微镜和接触角光度计的滴水蒸发动态.
- 使用原子力显微镜 (AFM) 描述干燥的微凝沉积物形态.
主要成果:
- PNIPAM微凝在空气-水界面上吸附和平整,形成有序的单层.
- 观察到复杂的沉积模式,包括统一的薄膜,咖啡环和多环模式.
- 沉积物形态取决于初始的微凝度和基板温度.
- 干燥微凝的平均高度随着基质温度的增加而增加.
- 微凝高度的空间异质性表明热调节的界面行为指导自我组装.
结论:
- 通过控制干燥条件和温度,PNIPAM微凝可以被模拟成各种结构.
- 温度在调节微凝界面活动和蒸发过程中的自我组装方面发挥着至关重要的作用.
- 本研究展示了一种使用温度反应敏捷的微凝制造调节性合膜的方法.
相关概念视频
02:31Phase Transitions
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to occupy...
02:39Phase Transitions: Vaporization and Condensation
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
02:39Phase Transitions: Melting and Freezing
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
02:33Phase Transitions: Sublimation and Deposition
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
01:21Phase Transitions
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...
01:28Transition Zone
The transition zone in concrete is a critical area where aggregate meets cement paste, marked by a distinct porosity and weakness compared to the surrounding material. The adhesion around the aggregates is primarily due to Van Der Waals forces. The voids within this zone influence its robustness; initially, it is less durable than the surrounding bulk mortar due to larger voids. Initially, when concrete is compacted, a higher water-cement ratio near the aggregates leads to the formation of...