NMR樣品置備
1.使用專屬NMR樣品管，將待測液體以玻璃滴管小心注入至樣品管底部
2.樣品液面高度至少3公分
數據X軸校正
取得數據後欲用ORGIN作圖得先進行X軸校正
orgin column校正公式為
Col(A) = Col (title) x [(first X- last X)/ B ] + last X
B 為X 軸第一個數字
first X 與 last X 為原始NMR scan 的範圍，可向技術員詢問
2018年12月12日 星期三
2018年11月4日 星期日
2018年10月14日 星期日
GITT量測設置範例
Reference :https://onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1002%2Fadma.201705580&file=adma201705580-sup-0001-S1.pdf
If sufficiently small currents are applied for short time intervals, so that dE/d√t can be considered linear and the coulometric titration curve can be also considered linear over the composition range involved in that step, the above equation can be simplified into:
- A cell was charged or discharged at 30 mA g-1 rate for 20 min, followed by a 3 h open circuit step to allow relaxation back to equilibrium (defined as dE/dt < 0.2 mV h-1).
- The procedure was continued until the charge (or discharge) voltage reached 1.8 V (0.2 V).
- The Zn2+ ion diffusion coefficients could be calculated using the following equation first outlined by Weppner and Huggins:
where, I is the current (A);
Vm is the molar volume of the ZVO (cm3 mol-1);
ZA is the charge number;
F is the Faraday’s constant (96485 C mol-1);
S is the electrode/electrolyte contact area (cm2);
dE/dδ is the slope of the coulometric titration curve, found by plotting the steady state
voltages E (V) measured after each titration step δ;
dE/d√t is the slope of the linearized plot of the potential E (V) during the current pulse of duration t (s).
If sufficiently small currents are applied for short time intervals, so that dE/d√t can be considered linear and the coulometric titration curve can be also considered linear over the composition range involved in that step, the above equation can be simplified into:
Here, τ is the duration of the current pulse (s);
nm is the number of moles (mol);
Vm is the molar volume of the electrode (cm3 mol-1);
S is the electrode/electrolyte contact area (cm2);
ΔEs is the steady-state voltage change, due to the current pulse and ΔEt is the voltage change during the constant current pulse, eliminating the iR drop.
2018年9月14日 星期五
XPS資料庫網站
1. NIST XPS database
https://srdata.nist.gov/xps/Default.aspx
2. Thermo Scientific
https://xpssimplified.com/periodictable.php
3.Handbook of X-ray Photoelectron Spectroscopy
https://www.cnyn.unam.mx/~wencel/XPS/MANXPS.pdf
2018年8月24日 星期五
量測鋰電池中鋰離子擴散係數方法
參考資料連結: http://www.cailiaoniu.com/35490.html
方法一：循環伏安法（Cyclic Voltammetry, CV）
方法特點
①要求是可逆體系（電化學步驟可逆）②優點是設備簡單，數據處理容易③缺點1：得到的只是表觀的擴散係數④缺點2：濃度變化△Co的確切值很難求得。
方法二：交流阻抗法（Electrochemical Impedance Spectroscopy, EIS）
方法特點
①可以直觀的看出是否受擴散控制②缺點1：得到的結果也只是一個表觀的擴散係數③缺點2：要求所測體系的摩爾體積V m不發生變化。
方法三：恆電位間歇滴定法（Potentiostatic Intermittent Titration Technique, PITT
方法特點
只需測電極的厚度，避開了電極的真實面積的大小和摩爾體積的變化。
方法四：電位弛豫法（Potential Relax Technique, PRT）
方法特點
①同PITT一樣只需測電極活性物質的厚度d②與PITT不同的是，PRT記錄的是電極電位隨時間變化的曲線，而PITT記錄的是電流隨時間變化曲線。
方法五：恆電流間歇滴定法（Galvanostatic Intermittent Titration Technique, GITT）
2018年7月1日 星期日
2018年6月18日 星期一
Standard Reduction Potentials of Organic Species
Standard
Reduction Potentials (E0'), 25oC
|
oxidant
|
reductant
|
n (electrons)
|
Eo´ (volts)
|
|
Acetate + carbon dioxide
|
pyruvate
|
2
|
-0.70
|
|
succinate + CO2 + 2H+
|
a-ketoglutarate + H2O
|
2
|
-0.67
|
|
acetate
|
acetaldehyde
|
2
|
-0.60
|
|
glycerate-3-P
|
glyceraldehyde-3-P + H2O
|
2
|
-0.55
|
|
O2
|
O2-
|
1
|
-0.45
|
|
ferredoxin (ox)
|
ferredoxin (red)
|
1
|
-0.43
|
|
Carbon dioxide
|
formate
|
2
|
-0.42
|
|
2H+
|
H2
|
2
|
-0.42
|
|
a-ketoglutarate + CO2 + 2H+
|
isocitrate
|
2
|
-0.38
|
|
acetoacetate
|
b-hydroxybutyrate
|
2
|
-0.35
|
|
Cystine
|
cysteine
|
2
|
-0.34
|
|
Pyruvate + CO2
|
malate
|
2
|
-0.33
|
|
NAD+ + 2H+
|
NADH +
H+
|
2
|
-0.32
|
|
NADP+ + 2H+
|
NADPH +
H+
|
2
|
-0.32
|
|
FMN (enzyme bound)
|
FMNH2
|
2
|
-0.30
|
|
Lipoic acid, ox
|
Lipoic acid,
red
|
2
|
-0.29
|
|
1,3 bisphosphoglycerate + 2H+
|
glyceraldehyde-3-P
+ Pi
|
2
|
-0.29
|
|
Glutathione, ox
|
red
|
2
|
-0.23
|
|
FAD (free) + 2H+
|
FADH2
|
2
|
-0.22
|
|
Acetaldehyde + 2H+
|
ethanol
|
2
|
-0.20
|
|
Pyruvate + 2H+
|
lactate
|
2
|
-0.19
|
|
Oxalacetate + 2H+
|
malate
|
2
|
-0.17
|
|
a-ketoglutarate + NH4+
|
glutamate
|
2
|
-0.14
|
|
FAD + 2H+ (bound)
|
FADH2 (bound)
|
2
|
0.003-0.09
|
|
Methylene blue, ox
|
Methylene
blue, red
|
2
|
0.01
|
|
Fumarate + 2H+
|
succinate
|
2
|
0.03
|
|
CoQ (Ubiquinone - UQ + H+
|
UQH.
|
1
|
0.031
|
|
UQ + 2H+
|
UQH2
|
2
|
0.06
|
|
Dehydroascorbic acid
|
ascorbic acid
|
2
|
0.06
|
|
Ubiquinone; ox
|
red
|
2
|
0.10
|
|
Cytochrome b2; Fe3+
|
Cytochrome b2; Fe2+
|
1
|
0.12
|
|
Cytochrome c1; Fe3+
|
Cytochrome c1; Fe2+
|
1
|
0.22
|
|
Cytochrome c; Fe3+
|
Cytochrome c;
Fe2+
|
1
|
0.25
|
|
Cytochrome a; Fe3+
|
Cytochrome a;
Fe2+
|
1
|
0.29
|
|
1/2 O2 + H2O
|
H2O2
|
2
|
0.30
|
|
Cytochrome a3; Fe3+
|
Cytochrome a3;
Fe2+
|
1
|
0.35
|
|
Ferricyanide
|
ferrocyanide
|
2
|
0.36
|
|
Cytochrome f; Fe3+
|
Cytochrome f;
Fe2+
|
1
|
0.37
|
|
Nitrate
|
nitrite
|
1
|
0.42
|
|
Photosystem P700
|
.
|
.
|
0.43
|
|
Fe3+
|
Fe2+
|
1
|
0.77
|
|
1/2 O2 + 2H+
|
H2O
|
2
|
0.816
|
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