polymer compositemtest

材料化學期末考題庫 2005/6/18

Band Theory
1. 名詞解釋
(a) density of state
(b) Fermi level
(c) s -band

2. Please explain the differences among metals, intrinsic, p-type and n-type
semiconductors, and insulators by using Band structure. Also, indicate the effect
of temperature on electrical conduction for each type of material.
3. Consider there are infinite Na atoms arranged linearly, with spacing d= a
between each atom. Please show that the Bloch sum of atomic orbital indeed
satisfy the periodic requirement of the wave function and draw the sigma band
(constructed with 3s orbital of Na atom) of this imaginary atomic line.

4. 簡單敘述由 s 軌域以一維結構排列形成的 E-k 圖趨勢以及其原因。同理分別
描述由 p 軌域及 s、p 交互形成的一維結構。
Ans:









5. What is P-N diode? What will happen if a diode in forward and reverse bias?
6. Is it possible that a ceramic or ionic solid might be a reasonable conductor of
electricity? What needs to occur?

7. density of state 的定義﹝請寫出數學式﹞。在 k space 中，圖形斜率越大的
時在以density of state 對energy 做圖時，代表著什麼意義？﹝參考下圖﹞


8. 何謂Fermi level 的定義？所謂的intrinsic 的半導體與extrinsic 的半導體差
異在哪裡？所謂的絕緣體，其band gap 有多大？



Catalytic Materials
1. List three classes of catalysts
Ans: Heterogeneous- The catalyst and the reactants are in different phases
Homogeneous- The catalyst and the reactants are in same phases
Biological- Enzymes
2. What is the importance of catalysis & catalytic processes?
3. 請說明 Heterogeneous Catalytic Reaction的反應過程.
4. The energy profile of surface-catalyzed reaction is shown below. The processes
include: (a) Diffusion to the surface; (b) Adsorption of reactant; (c) Surface
diffusion of reactants; (d) Surface reaction; (e) Surface diffusion of products; (f)
Desorption of products; (g) Diffusion away from the surface.
Which processes do steps (1) and (2) (in the diagram) correspond to?

(2)
(1)
(2)
(1)

Ans: (b)、(f)
5. TiO2 在光觸媒反應下如何形成．OH?
6. Show the mechanism of Rh catalyzed methanol carbonylation

7. Please explain Monsanto synthesis.
8. 我們都知道觸媒跟反應物的接觸面積是越大越好，但是除此之外，奈米級的
觸媒會有甚麼額外的反應?
9. 車輛所排放之廢氣中，對環境危害最嚴重的是哪三種氣體？目前的汽車安裝
的觸媒轉化器是用什麼觸媒來去除這些毒性物質？請寫出反應式.
Ans: 一氧化碳（CO）、 氮氧化物（NO
x
）與 unburned hydrocarbons（HC）。 …

10. 簡述燃料電池原理, 並討論 PEMFC, MCFC, SOFC 的差異性與優缺點
11. 這是三種酵素產生反應速率變化的圖形，縱座標為反應速率，請分別指出橫
座標何者為溫度、受質濃度及酵素濃度，並簡述曲線變化的原因。

A：
(A) 橫座標為酵素濃度；只需要極少量酵素便可催化反應，且不論含量多少，都
不會影響反應進行。
(B) 橫座標為受質濃度；一開始，隨著濃度增加，粒子碰撞產生反應的機率也增
加，但上升到一定濃度之後，粒子的有效碰撞就不再因濃度升高而增加。
(C) 橫座標為溫度；溫度增加會增加粒子有效碰撞機率，因此一開始直線上升，
但溫度過高蛋白質會開始變性，導致酵素失去活性，而無法催化反應。

12. 孔洞物質如何扮演觸媒角色？

Characterization
1. What are the basic theories of XANES and EXAFS? What kind of informations
can be obtained from these spectra.
2. What are the differences between EPR 和 NMR?
3. What is Scherrer equation? Its application?
4. Describe the possible reasons for the hysteresis occurred in the N2 adsorption-
desorption isotherm of porous materials

5. Briefly explain the meanings of the five common isotherms in physical adsorption
of N2 on materials.
6. 試說明氮氣吸脫附的原理, 如何由圖形辨別孔洞大小
7. Please explain the difference between DSC (differential scanning calorimetry) and
DTA (ifferential thermal analysis). What kind of information can be obtained from
these analysis techniques?
8. 下圖為由Differential Scanning Calorimetry (DSC)得到之數據，請解釋
A、B、C三區域各代表何種現象之發生。


9. 簡述 photoelectron spectroscopy的原理及分類?
10. In UPS, solid phase spectrum often have peak shift and broadening compared to
gas phase spectrum. Why ?
A
B C
Answer : because solid phase have charging effect, molecular solid bonding, and
relaxation effects
11. 由這張
29
Si MAS NMR 光譜，簡單說明 MCM-41 這種孔洞材料具備何種性
質。

Ans:The wall of MCM-41 is amorphous.
12. If we want to know the oxidation state and coordination of titanium
in the mesoporous material, what techniques can we use to determine?
And write a short esay to explain the basic principles about these instruments.
(at least three techniques)


Composite Materials

1. composite materials 包含那兩大部分?作用為何?
2. 為何水中加氟可以強化牙齒結構?


Conducting Polymer
1. 請解釋何為 conducting polymers?其導電的機制是如何？並說明 conducting
polymer 的用途。
2. Explain the applications of conducting polymers.
ANS.
1. electromagnetic shielding of electronic circuits
2. antistatic coating material to prevent electrical discharge exposure on
photographic emulsions
3. hole injecting electrodes for OLEDS
4. electroluminescent displays(mobile telephones)
5. emissive layer in full-color video matrix displays
6. field-effect transistors (usage in supermarket checkout)
7. absorb microwaves: stealth technique


Crystal Growth
1. 控制單晶之大小及純度的因素?
Ans:
Nucleation and Growth:
Slow nucleation rate and rapid growth lead to large crystals
Rapid nucleation rate and slow growth lead to small crystals
2. What can you do to control the nucleation rate？
Ans: (a) slow cooling of melts
(b) temperature gradients
(c) introduction of seed crystals
3. Zone melting and Czochralski Method are the two method to grow crystal.

please describe each of them.
4. (a) State the variety of crystal growth technologies according to their
development.
(b) Which of them is extensively used in the semiconductor industry? What
is it advantage?
ANS. (a) 1. Verneuil’s method
2. Czochchralski method
3. Kyropoulos method
4. Bridgeman method
5. Floating Zone method
6. Stockbarger method
7. Zone melting method
(b) Czochchralski method is extensively used in the semiconductor industry. It is
that large single crystals can be grown.
5. How to prepare the films?
ANS. Dip Coating
Spin Coating
Vapor Deposition
Chemical Vapor Deposition
6. Based on phase diagram, please explain Congruent Melting, Incongruent Melting,
Multiple Incongruent Melting.
7. Explain the following terms:
a. Epitaxial growth.
b. Molten salt fluxes.


Nanoporous Materials
1. Describe some properties that chang while the size of the material decreasing.
2. Classify nanoporous materials in diameter?
ANS. Microporous, d<2nm

i. Mesoporous, 2nm<d<50nm
ii. Macroporous d>50nm
3. 請列出四種奈米孔洞材料的應用
4. 增加材料孔洞大小的方法有哪些？
Ans: 可以延長 surfactant alkyl chain 使被 silica 包住的 micelle 變大。也可以
加入 solubilization agent 來增加孔洞的大小。
5. 分析奈米粒子(nano-particle)大小的方法有哪些，是簡述。
6. 簡述 g 值與孔洞性質的關係。
7. Some porous meterials are commonly synthesized with cationic surfactant and
silicate. Please give some arguments about how the surfactant concentration,
surfactant/ silicate concentration ratio, counter ion of the surfactant and structure
of the surfactant affect the final structure of the porous material.
8. Please compare M41S and SBA-15.
Ans ：
M41S SBA-15
Finder C.T. Kresge 1992 D. Zhao 1998
Si source Sodium silicate TEOS(tetraethylorthosilicate)
Pore-directing
agent
CTMA
(Cetyltrimethylammonium ion)
Amphiphilic triblock copolymers
Acidity pH~10 > 0.1 M HCl
Temperature ~100 ℃ 35~80 ℃
pore interlink no yes

9. Distinguish the differences between “Zeolites” and “Molecular sieves”.
Ans: Zeolites- crystalline aluminosilicate structures
Molecular Sieves- materials which can separate molecules by molecular size
10. 對於奈米孔洞材料，有哪些方式可以測量其表面積及鑑定其屬於何種

類型之孔洞。
11. 試由材料之結構方面比較測量奈米孔洞材料之 XRD（小角度 XRD）與一般
塊材之 XRD（較高角度）之相異處。
Ans: 塊材之 XRD 是測量晶格中原子長程有序排列之結構，而孔洞材料之小角度
XRD 則是測量孔洞之有序排列，而非晶格中原子之排列。而晶格中原子間距與
晶面間距為數個埃（angstrom，Å ）， 孔洞材料其孔洞大小及孔壁厚度則為奈米等
級（nanometer，nm）， 故由 2dsin? = n? 得知，d（繞射面間距）越大，繞射峰會
出現於越小角度處，故孔洞材料 d 較大，其繞射峰會出現於較低角度的地方。
11. 分子篩可以用於純化與催化反應的原理是什麼？
Ans: 在製作分子篩的同時可以針對想要的反應分子設計適合的孔洞大小，如此
一來只有我們想要反映的分子才會進入到分子篩中反應，可以增加反應
的專一性並且增加反應分子正確碰撞的可能性以增加反應速率。另外也
可以直接利用孔洞大小限制能通過的分子來過濾達到純化的效果。

OLED
1. 請解釋 LCD 的原理, 請和 OLED 作比較。
2. OLED 有哪兩種?各自優缺點為何?
A:有 small mollicule oLED 跟 pLED 兩種，small mollicule oLED 發展比較
成熟，但是需用到真空製模技術成本較高，pLED 使用 polymer 取代小
分子可以直接用 ink-pringing 的方法大量製造，唯有現在發展還未成熟
在許多表現都不如小分子 oLED。
3. Describe briefly the phenomenon of luminescence. What is the distinction
between fluorescence and phosphorescence?
4. Describe briefly the principle of luminescence of light emitting diode (LED).
5. Describe briefly the TFT-LCD.
6. Describe the mechanism of the tuning of energy gap by donor and acceptor in
OLED
7. Please enumerate three advantages of Alq
3
.

Ans ： (1) Ball-shape molecule: Hard to crystallize
(2) Six-Coordinate metal: Chemically inert
Metal stabilize chelating ligand
High T
d
>350 ℃ thermally stable
(3) Availability: Very easy to synthesize and not expansive
8. 請簡單描述 OLED 的發光原理並畫出目前最常用的三層式 OLED 元件組。
9. OLED 通常都使用 ITO 當作陰極的原因？
Ans: ITO 透明而且可以導電，其還原電位與大部分的有機發光分子的 HOMO 相
差不遠。
10. 在 Alq3 dope DCM1 就可以改變 LED 的顏色，原理為何？
Ans: DCM1 的吸收波長剛好與 Alq3 的螢光波長相符，並且兩者之間會有
dipole-dipole interaction，所以會進行 Forster type energy transfer，所以最後會放
出 DCM1 的紅光。
11. 如何產生 Full Color OLEDs?
12. What are the changes in MO energies when the molecule has donor and acceptor
substitution?
Ans:










Polymer Materials

1. What is the difference between “addition polymer” and “condensation polymer”?
2. What is the difference between “high-density polyethylene (HDPE)” and
“low-density polyethylene (LDPE)”?
3. What is the difference between “thermoplastic polymer” and “thermosetting
polymer”?
4. What are the reaction steps in preparing addition polymer
Ans:
(1) Initiation - often through the use of free-radicals.
(2) Propagation - radicals join to form larger radicals.
(3) Termination - occurs when a molecule is formed that no longer has an
unpaired electron.
4. Please explan what are isotactic, syndiotactic and atactic.
5. What is “Vulcanization”? What kind of polymer can use vulcanization to change
its property? How?
6. How does ion-conducting polymer conduct electrons?
7. 請解釋 T
m
和 T
g
的意義。
8. Please describe glass transition phenomenon of the polymers and provide a
method to measure the glass transition temperature.
9. Sketch how the liquid crystal works with polarizer, voltage and reflector to
control bright and dark spot.
10. 請問 ABS-Polymer 的 A，B，S 各表示甚麼分子？
11. Please use A and B to present the following copolymer : (a) alternating (b) random
(c) block (d) graft
Ans ：(a) alternating A-B- A-B- A-B- A-B- A-B- A-B-
(b) random A-B-A-A-A-B-B-A-A-B-A-A-B-A
(c) block A-A-A-A-A-B-B-B-B-A-A-A-A-A-A-B-B-B

(d) graft

B-B-B-B-B

B
-
B
-
B
-
B
-
B
A-A-A-A-A-A-A-A-A-A-A-A-A-A-

15. Please describe the structure of liquid crystalline polymers : (a) nematic (b)
smectic (c) cholesteric
Ans:
液晶分子在空間上具有一維的規則性排列, 所有棒狀液晶
分子長軸會選擇某一特定方向作為主軸並相互平行排
列. 而且不像 smectic 一樣具有分層結構.


具有二度空間的層狀規則性排列，各層間則有一度的順向
排列。其結構是由液晶棒狀分子聚集一起, 形成一層一層
的結構. 其每一層的分子的長軸方向相互平行. 且此長軸
的方向對於每一層平面是垂直或有一傾斜角. 由於其結構

非常近似於晶體, 所以又稱做近晶相

如果把它的一層一層分開來看, 會很像線狀液晶. 但是在
Z 軸方向來看, 會發現它的指向矢會隨著一層一層的不同
而像螺旋狀一樣分佈,




16. 請寫出兩種以上高分子分子量的定義及物理意義。並回答何者為
polydispersive？
Ans:

17. If we have a polymer sample consisting of 9 moles having molecular weight
30000 and 5 moles having molecular weight 50000, what is its polydispersity index?
Ans:
08.1
37000
40000
/40000
)500005()300009(
)50000(5)30000(9
/37000
59
)500005()300009(
22
2
===
=
×+×
+
==

=
+
×+×
==
∑
∑
∑
∑
n
w
ii
ii
w
i
ii
n
M
M
PDI
moleg
MN
MN
M
moleg
N
MN
M

Solid Synthesis
1. Dinstinguish Single crystals and polycrystalline samples.
2. 何為 solid state reaction？其反應可能遇到的問題是什麼？又如何解決此問
題？
3. What can you do to increase the rate of diffusion in a solid state reaction?
Ans： (a) increase temperature
(b) introduce defects by starting with reagents that decompose prior to or during
rxn
4. 請簡述 chemical vapor deposition(CVD)的原理。
Ans: (CVD) is a chemical process for depositing thin films of various materials. In a
typical CVD process, the substrate is exposed to one or more volatile precursors,
which react and/or decompose on the substrate surface to produce the desired deposit.
Frequently, volatile by-products are also produced, which are removed by gas flow
through the reaction chamber.
5. Explain the following terms in solid synthesis
(a) Solid State Metathesis Reactions
Ans: A metathesis reaction between two salts merely involves an exchange of anions,
although in the context we will use there can also be a redox component. If the
appropriate starting materials are chosen, a highly exothermic reaction can be devised.
(b) Hydrothermal Synthesis
Ans: Reaction takes place in superheated water, in a closed reaction vessel called a
hydrothermal bomb (150 < T < 500 °C; 100 < P < 3000 kbar). Seed crystals and a
temperature gradient can be used for growing crystals
(c) Sol-gel process
(d) Intercalation
Ans: Involves inserting ions into an existing structure, this leads to a reduction
(cations inserted) or an oxidation (anions inserted) of the host. Typically carried out
on layered materials (strong covalent bonding within layers, weak van der Waals type
bonding between layers, i.e. graphite, clays, dicalchogenides,). Performed via
electrochemistry or via chemical reagents as in the n-butyl Li

technique.
(e) Dehydration
Ans: By removing water and/or hydroxide groups from a compound, you can often
perform
redox chemistry and maintain a structural framework not accessible using
conventional synthesis approaches
(f) Ion Exchange
Ans: Exchange charge compensating, ionically bonded cations (easiest for
monovalent cations)
6. 於固態反應法中，需將原料研磨使其混合均勻，為何以固態反應法進行實驗
時要先將原料研磨混合呢？
Ans: 固態反應法最重要的因素為 Diffusion，若不研磨而進行反應，融熔態之
Diffusion速率並不夠高，與研磨後而進行反應相比較，不研磨而進行反應其原料
間的接觸面積不夠大，會讓反應不完全，故要研磨均勻後再進行反應，增加原料
間接觸面積，使反應較易進行。
6. 化學氣相沉積( CVD)鍍膜技術中所用之前驅物(Precursor)之選擇應考慮的因
子有哪些？
7. Please draw a schematic diagram for each following different self-assembled
membrane structure.
i. reversed micelle
ii. bilayer
iii. vesicles
8. Please interpret advantages and disadvantages of precursor routes for solid
reactions.
Ans：Advantages
i. lower rxn temperature
ii Decreasing the diffusion distance since the precursors are pre-mixed in
the solution.
iii production of products with small crystallites & high surface area
Disadvantages

i. hard to control exact stoichiometry
ii. sometimes it’s impossible to find compatible reagents
9. What can you do to increase the rate of diffusion in a solid state rxn？
Ans：(a) increase temperature
(b) introduce defects by starting with reagents that decompose prior to or during
rxn
10. In solid synthesis, what are the consequences of high reaction temperatures?
Ans:
1. It can be difficult to incorporate ions that readily form volatile
species (i.e. Ag+).
2. It is not possible to access low temperature, metastable
(kinetically stabilized) products.
3. High (cation) oxidation states are often unstable at high
temperature, due to the thermodynamics of the following reaction:
2MOn (s) à2MOn-1(s) + O2(g)
Due to the release of a gaseous product (O2), the products are favored by
entropy, and the entropy contribution to the free energy become increasingly
important as the temperature increases.
11. Write a short essay about Sol-Gel process, and distinguish between xerogel and
aerogel?