胶体与表面化学 试题

一、是非题

1.表面超量的英文具体描述：

The surface excess of solute is that the number of moles of solute in the sample from the surface minus the number of moles of solute in the sample from the bulk under a condition of the same quantity of solvent or the surface excess of solvent has been chosen to be zero. 2.囊泡的形成途径：

The final surfactant structures we consider as models for biological membranes are vesicles. These are spherical or ellipsoidal particles formed by enclosing a volume of aqueous solution in a surfactant bilayer. Vesicles may be formed from synthetic surfactants as well. 3.絮凝与聚焦之间的区别： Coalescence：the process that many small particles take together to form a new big particle,total surface area of the dispersion system decreases.

Aggregation:the process by which small particles clump together like a bunch of grapes (an aggregate), but do not fuse into a new particle,total surface area of the dispersion system do not decrease as well.

4.胶束micelle：A monophasic, fluid, transparent, isotropic and thermodynamically stable system composed by surfactant and water, the particle has some linear dimension between 10-9-10-6m. 5.乳液emulsion：A multiphasic, no-transparent and thermodynamically unstable system composed by surfactant, cosurfactant, oil and water.

6.微乳液microemulsion：A monophasic, fluid, transparent, isotropic and thermodynamically stable system composed by surfactant, cosurfactant, oil and water. 7.囊泡vesicle：能不能直接从双联续制备转换过来？（√）

8.憎水溶胶 亲水溶胶 连续相与分散相有没有明显界限？（没有） 9.胶束体系的稳定性与哪些因素有关？与哪些因素无关？ 10.瑞利散射：条件 粒子大小

11.表面吸附超量γ：物理意义 溶剂的量是不是都为零？（×）

12.TEM、SEM都需要把样品放入真空中，最后结果都可以表明原来分散度。（×） 13.在Langmuir膜、LB膜 单层 理想气体方程式 能否用理想气体关系式描述？（能） 二、多项选择题

1.表面吉布斯自由能：

The Gibbs equation:multicomponent systems G?Vdp-SdT???dnii?Ad?

From Gibbs-Duhen equation:∑μidni=0 注：G?G?G?G；

??SG?E?pV?TS???ini；

iGs?Es??A?TSs???ini；

i dG? dG? dG?(dE?pdV?Vdp-TdS?SdT???dn??nd?)?Ad???dA； ???iiii,,sii(Vdp-SdT???dn??nd????iii,,siiiii,,siii-?wnom-pV)?Ad???dA；

(Vdp-SdT???dn??nd?)?Ad?； ???iidG?Vdp-SdT???idni

2.几个半径之间的相互关系：

Martin Diameter≤Graticule Diameter,

Number Average Diameter(dn)

7.电镜的数值孔径： d??2nsin???2NA

NA?nsin?（NA is called the numerical aperture of the lens.）

NA：临界参数，同一仪器该值为定值；θ：目镜与棱镜一级散射时的夹角 8.各种半径的相对大小：dn < ds < dv 9.AFM：原子力显微镜

10.稳态条件下扩散系数D与阻力因子f之间的关系： D?kBT f（1）f与粒子大小、形状、介质因素有关

（2）粒子为球形，f?6??r浓度梯度越大，质点扩散越快； 就质点而言，半径越小，扩散能力越强。

?9???（3）椭球：f?6????2(???)21??11.第二维利系数：（分子量参数） Second vivid：B?1/2

1NAu（mol m3 kg-2）其实质是代表介质中分子间作用力大小。（solute 22Mand solvent intercation）其反映一对分子间的相互作用造成的气体性质与理想气体的偏差。是联系气体的宏观热力学性质与微观分子力学参量的一条有效途径。它不仅在实用上可表示真实气体的状态，而且在理论上还可验证和发展分子作用势模型，确定分子力学参量，从而预测物质的其它宏观性质。

12.毛细管产生末端效应的原因：

A. 压力差≠0 B. 流速≠整个流体的均匀体积速度（√） C. 通过每个界面的速度不等 D. ……不是一个常数

用毛细管粘度计测量粘度，要求流体通过上下刻度时，流速要一致。为保持流速一致，毛细管粘度计有两个相对较大的球，上面的一个球也要注入液体来消除上末端效应，保证流体

流经上刻度时，速度保持均匀；为消除下末端效应，要保证液体中无气泡，下刻度不能太靠下，应靠近下一个小球。

13.光散射过程中，光散射强度与什么因素有关：

is2?2M ?24(n?1)2(1?co2s?x) I0r?0NA?（1）与入射光波长的四次方成反比；（2）与粒子体积的二次方成正比（只适用于粒子直径在5~100nm）；（3）与体系的折射率（refractive index）有关；（4）与单位体积内的粒子数目成正比。

Depend: ①wavelength of the incident light ②the size and shape of the scattering particles ③the optical properties of the scatters ④the angle of observation 14.动力学方程的最简方程（无重力）： Navier-Stockes 方程：?（????）??????g??????2? ?t 左一：低流速下忽略 左二：任意位置时，速度对时间的变量（加速度），稳态时忽略 右一：重力 右二：压力 右三：粘滞力 15.德拜散射方程：

?16?2R2?Kc?1??g2??? ???2Bc?1?sin??? 2R??M3????2???? （1）in the limit of θ=0, there is no interference effect in the scattering light.

（2）in the limit of c→0, Kc/Rθ is proportional to sin2(θ/2). （3）in both θ and c→0, Kc/Rθ equals to 1/M. The Debye scattering model:

A: Allowing the particles approximate the wavelength of incident light.

B: The interference between the waves of light scattered from different parts of the same particle.

C: A large particle does not consist of merely two scattering centers, but may be subdivided into several centers, the number of which increases with the size of the particle.

注：德拜散射方程理论应对哪个结论关系？Rayleigh model assumptions（瑞利假设） 16.动态光散射产生条件：

DLS产生波动性的主要原因：random motion 17.LB膜产生的原因（哪些分子可以产生LB膜）： 基本要求：分子具有两亲性

（1）分子应具有与水有一定亲和力的亲水端

（2）分子应同时具有足够长的疏水脂肪链，使分子能在水面上铺展而不溶解 注：有一个物质形成的单层，不用于下面什么单层？（LB膜）

LB膜的关键：A.灵敏度 B.温度 C.moving race D.Leak proof of system 18.堆积参数在1/2~1/3之间形成什么样胶束？ A.球形 B.层状 C.圆柱棒状 D.弹性双层 注：见问答题第2题表。 19.三种作用力产生的原因：

Debye equation: permanent dipole / induced dipole interaction Keeson equation: permanent dipole / permanent dipole interaction London equation: induced dipole / induced dipole interaction 20.双电层的电性与哪些因素有关： pH、T、……、all above

三、问答题

1.LB膜与表面压的定义，描述实验中如何制备LB膜，测量LB膜的关键因素，解释典型的LB膜曲线。

（1）LB layers：Monolayers formed by a substance that is insoluble in the liquid subphase are labeled Langmuir layers. Langmuir layers transferred to solid substrates are known as Langmuir-Blodgett (LB) layers.

Surface pressure：2D pressure produced by insoluble molecules doing free movement on the surface of water and colliding with the floating sheet are known as surface pressure. It means the force exerted on the unit length which is represented by π.

（2）Assembly process of LB films：When insoluble substances spread on the surface and form a monomolecular layer, insert a plate into the liquid level. It will form a monolayer of LB films at both sides of the plate when pulling out the plate. After drying, insert the plate into the liquid level again and it will form a bilayer membrane. And so on, it may form multilayer film, following the principle of \（3）Measurement keys：

①The system must be leakproof. The float and flexible barriers must always be hydrophobic. ②The tray and barriers must be carefully machined to assure good contact. ③The water level be controlled quite accurately.

④The torque must be measured with sufficient sensitivity to yield meaningful results. ⑤Temperature is important in any equation of state. The experiment should be isothermal. ⑥Contaminants or impurities must be very littlest.

⑦The pH and ionic strength and other properties of the solution should be constant. （4）

S: the solidlike phase LC: the liquid-condensed phase I: the intermediate liquid phase LE: the liquid-expanded phase LE/G: the liquid-expanded/gaslike coexistence region G: the gaslike phase

2.堆积参数与胶体结构之间的关系。

Critical packing parameter <1/3 1/3-1/2 1/2-1 ~1 >1

Critical packing shape Cone Truncated cone Truncated cone Cylinder Inverted truncated cone or wedge Structure formed Spherical micelles Cylindrical micelles Flexible bilayers, vesicles Planar bilayers Inverted micelles

3.胶体体系结构之间的转化。

4.胶化是否有用？举例说明（2~3个）。

Colloid is widespread in nature especially in biosphere. It keeps close touch with human life and environment. The application of colloid is very broad. Many important materials and phenomena in industrial production and daily life are related with colloid at some extent.

①Daily life: tofu (colloidal coagulation), beer, waterproof cosmetics, capsules prepared.

②Biochemistry and Molecular Biology: electro-osmosis, penetration ,film balance and other film phenomenon.

(1) Antifogging glasses: It increases the spreading coefficient and makes liquid expand automatically on solid surface to form a thin film.

(2) Waterproof raincoat: It increases the contact angle θ of solid-liquid interface and makes the droplet spherical non-wetting solid

(3) Paper electrophoresis: Under the action of electric field, different colloidal particles in the dispersion medium do directional movement in different electrophoretic velocity.