Supplementary Information
“Modular
β-cyclodextrin
and
polyoxyethylene
ether
modified
water-soluble
polyacrylamide for shale hydration inhibition”
Wenchao Jiang, Zhongbin Ye, Shaohua Gou, Xiangjun Liu, Lixi Liang, Wan Wang and
Zewen Song
Preparation of copolymer
The appropriate amounts of AM, AA, APEG, O-β-CD were placed in a beaker while
stirred in distilled water under an inert nitrogen atmosphere, and NaOH was added into the
solution to adjust the pH stirring for 10 min to achieve a certain temperature, then the
copolymerization proceeded being thermally insulated for 8–10 h until the reaction ended.
After the products were cooled to room temperature (25 oC), it was separated by
precipitation using ethanol and dried at 45 ◦C vacuum oven retrieving the powdered
copolymer AM/AA/APEG/O-β-CD sample. And the relationship between apparent
viscosity of copolymer solutions and synthesis conditions are shown in Table. S1 and S2.
Table S1.
The effects of the initiator concentration, pH and temperature on AM/AA/APEG/ O-β-CD
Initiator (wt %)
pH
Temperature(oC)
Apparent Viscosity (mPa·s)b
Conversion(%)c
0.3
7
40
232.6
91
0.5
7
40
375.9
92
0.7
7
40
410
97
0.9
7
40
352.9
93
1.1
7
40
295.1
95
0.5
5
40
340.4
90
0.5
7
40
422.3
95
0.5
9
40
356.9
93
0.5
10
40
272.1
92
0.5
11
40
210.5
90
0.5
7
30
370.1
90
0.5
7
35
564.8
94
0.5
7
40
413
97
0.5
7
45
324
95
0.5
7
50
253.1
95
aConditions:
bApparent
AA/AM/APEG/O-β-CD= 6.5/3/0.48/0.02 (wt), concentration=20 % (wt%).
viscosity: copolymer solution=1000 mg/L, tested by Brookfield DV - II + Pro Viscometer at 30 oC.
cConversion
(wt %): AM, tested by HPLC using ODS column at UV detector (210nm),
H2O/CH3OH = 90/10 (v/v).
Table S2.
a
The effects of the ratio of AM, AA, APEG and O-β-CD on AM/AA/APEG/ O-β-CD
AM (wt)
AA (wt)
APEG (wt)
O-β-CD (wt)
Apparent Viscosity (mPa·s)b
Conversion (%)c
6
3.5
0.48
0.02
423.3
93
6.5
3.0
0.48
0.02
346.3
93
7
2.5
0.48
0.02
356.3
97
7.5
2.0
0.48
0.02
317.9
95
8
1.5
0.48
0.02
274.9
95
7.38
2.5
0.1
0.02
329.5
95
7.18
2.5
0.3
0.02
369.5
95
6.98
2.5
0.5
0.02
455.2
93
6.78
2.5
0.7
0.02
354.6
93
6.58
2.5
0.9
0.02
390.3
95
6.99
2.5
0.5
0.01
422.4
93
6.985
2.5
0.5
0.015
438.5
95
6.98
2.5
0.5
0.02
453.5
98
6.975
2.5
0.5
0.025
528.3
94
6.97
2.5
0.5
0.03
485.6
91
Conditions: initiator loading= 0.7 wt %, pH= 7, Temperature= 35 oC, concentration=20% (wt%).
b
Apparent viscosity: copolymer solution=1000 mg/L, tested by Brookfield DV - II + Pro Viscometer at 30 oC.
c
Conversion (wt %): AM, tested by HPLC using ODS column at UV detector (210nm), H2O/CH3OH = 90/10 (v/v).
Intrinsic viscosity measurement
Intrinsic viscosities of copolymers solutions were measured using an Ubbelohde
viscometer at 30 oC at five different concentrations (1.00, 0.67, 0.50, 0.33, 0.25 mg/L).
Copolymer samples were dissolved in the 1.0 mol/L NaCl solution and then diluted to the
required concentration by adding NaCl solution into the flask in a constant temperature
bath at 30 oC. The flux time was recorded with an accuracy of 0.05 s. And the result is
shown in Figure S1.
Figure S1. Intrinsic viscosity result of AM/AA/APEG/O-β-CD.
Measurement of MMT crystalline interspace
After drying, the MMT was prepared as 11 samples and each weighed 2 g. First, the
crystalline interspace of dry MMT was measured. Then, the MMT sample was mixed with
copolymers solutions of which the concentration was confirmed by core stress test. And
different salts (10 wt %; KCl, NaCl, and CaCl2) were added into the copolymer solution
with certain concentration, respectively. And these solutions would be mixed with new
MMT samples. All above MMT samples were made into tablet and the crystalline
interspace would be measured by X-ray diffraction.