什么是泡沫的稳定性？表面活性剂如何影响泡沫寿命？
What is foam stability, and how do surfactants affect foam lifetime?
泡沫是气体分散在液体中的多相体系，其稳定性取决于液膜排液速度与表面膜的弹性修复能力。表面活性剂降低表面张力并提供 Marangoni 效应，使液膜受扰动时自动补强，从而延长泡沫寿命。
A foam is a dispersion of gas in liquid whose stability depends on the drainage rate of the liquid films and the elastic self-healing of surface films. Surfactants lower surface tension and provide the Marangoni effect, automatically reinforcing films under disturbance and prolonging foam life.
难度 专业 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#泡沫 #液膜 #Marangoni效应
根据 DLVO 理论，胶体颗粒的稳定性由哪两种相互作用决定？为什么加入电解质会使胶体聚沉？
According to DLVO theory, which two interactions determine colloidal stability, and why does adding electrolyte cause coagulation?
DLVO 理论认为胶体稳定性由范德华吸引与双电层静电排斥的叠加决定，总势能曲线存在能垒阻止聚沉。加入电解质压缩双电层、降低 ζ 电势，使排斥能垒减小甚至消失，颗粒因热运动碰撞而聚沉。
DLVO theory states colloidal stability comes from the balance of van der Waals attraction and double-layer electrostatic repulsion, with an energy barrier in the total potential preventing aggregation. Adding electrolyte compresses the double layer and lowers the zeta potential, shrinking or removing the barrier so particles collide and coagulate.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#DLVO理论 #双电层 #聚沉
接触角和杨氏方程描述了什么？超疏水表面的接触角一般有多大？
What do contact angle and Young's equation describe, and how large is the contact angle of a superhydrophobic surface?
接触角是液滴在固体表面气-液-固三相交界处与固体的夹角，杨氏方程 cos θ = (γsv − γsl)/γlv 把接触角与三个界面张力联系起来，反映润湿性。超疏水表面的接触角通常大于 150°，水滴近乎球状滚落。
The contact angle is the angle a liquid drop makes with a solid at the three-phase line, and Young's equation cos θ = (γsv − γsl)/γlv links it to the three interfacial tensions, reflecting wettability. A superhydrophobic surface shows a contact angle usually above 150°, with droplets nearly spherical and rolling off.
难度 进阶 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#接触角 #杨氏方程 #超疏水
什么是凝胶？它和溶胶在状态上有什么区别？
What is a gel, and how does it differ in state from a sol?
凝胶是分散相通过三维网络将分散介质包裹其中、失去流动性的半固体体系；溶胶则是固体微粒分散在液体中仍能流动的胶体。凝胶多由溶胶在适当条件下聚结或交联形成，如琼脂、硅胶。
A gel is a semisolid in which a three-dimensional network of the dispersed phase traps the dispersion medium and loses fluidity, whereas a sol is a flowing colloid of solid particles in liquid. Gels typically form when a sol coagulates or cross-links under suitable conditions, e.g., agar or silica gel.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#凝胶 #溶胶 #三维网络
什么是乳化现象？乳化剂稳定乳状液的原理是什么？
What is emulsification, and how do emulsifiers stabilize an emulsion?
乳化是把一种不互溶液体分散成微小液滴混入另一种液体形成乳状液的过程。乳化剂（表面活性剂）吸附在液-液界面，降低界面张力并形成机械或电荷屏障，阻止液滴聚并。
Emulsification disperses one immiscible liquid as fine droplets into another to form an emulsion. An emulsifier (surfactant) adsorbs at the liquid-liquid interface, lowers interfacial tension, and forms a mechanical or charge barrier that prevents droplet coalescence.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#乳化 #乳状液 #表面活性剂
什么是布朗运动？它与胶体颗粒为什么长时间不沉降有关吗？
What is Brownian motion, and is it related to why colloidal particles stay suspended for a long time?
布朗运动是悬浮微粒受周围分子不平衡碰撞而产生的无规运动。它能使胶体颗粒不断随机位移，部分抵消重力沉降，但胶体长期稳定主要靠双电层排斥和溶剂化层，而非布朗运动本身。
Brownian motion is the random movement of suspended particles from unbalanced molecular collisions. It gives colloidal particles continuous random displacement that partly counters gravitational settling, but long-term colloidal stability mainly relies on double-layer repulsion and solvation shells rather than Brownian motion alone.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
A. Einstein,《由分子运动论所要求的悬浮微粒的布朗运动》,Ann. Phys. 1905,17,549
A. Einstein, Ann. Phys. 1905, 17, 549
#布朗运动 #胶体悬浮 #沉降
什么是表面张力？液体表面为什么会存在表面张力？
What is surface tension, and why does it exist at a liquid surface?
表面张力是液体表面单位长度上收缩的力，来源于表面层分子受到的内部分子净向内拉力。表面分子配位不饱和、能量较高，液体因而趋向于缩小表面积以降低表面能。
Surface tension is the contractile force per unit length at a liquid surface, arising because surface molecules experience a net inward pull from the bulk. With unsatisfied coordination and higher energy, the liquid tends to minimize its surface area to lower surface energy.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
傅献彩 等,《物理化学》第5版,高等教育出版社,2005
Fu Xiancai et al., Physical Chemistry, 5th ed., Higher Education Press, 2005
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787040167696（按标识回读: 物理化学(第五版)上册）
#表面张力 #表面能 #液体界面