Synthesis and Characterization of pH and Temperature-Sensitive Semi-IPN Hydrogels

2014 ◽  
Vol 1053 ◽  
pp. 224-230
Author(s):  
Shan Jiang ◽  
Xia Qian Li ◽  
Qiang Yu

A series of novel cross-linked poly N-isopropylacrylamide (PNIPAM)/poly diallyl dimethyl ammonium chloride (PDMDAAC) semi-IPN hydrogels were synthesized through free radical solution polymerization in water at 30°C. FTIR was used to characterize the structure of resultant hydrogels. The pH and temperature sensitivity of hydrogels were systematicly studied, and the swelling properties of hydrogels were also explored. The results show that the semi-IPN hydrogels have both temperature and pH sensitivities. The hydrogels exhibit fast swelling rate and excellent stimuli-responsive behavior.

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Qin Yu ◽  
Xiangguo Lu ◽  
Yubao Jin ◽  
Cui Zhang ◽  
Kuo Liu ◽  
...  

Microspheres have excellent sealing performances such as injectivity, bridging-off, deep migration, and deformation performances, but their plugging effects are limited by the fast swelling rate and poor viscoelasticity. In this study, we synthesized a novel modified microsphere with polymerizable surfactant monomers and cationic monomers. We investigated the influence factors on the swelling performance and rheological properties of the microspheres and explored the ways to improve the plugging performance of hydrophobic-associating microspheres. The association behaviors in aqueous media of poly(acrylamide-co-methacry loyloxyethyl trimethyl ammonium chloride-co-n-dodecyl poly(etheroxy acrylate) P(AM-DMC-DEA) are proven to be mediated by the DEA content. Moreover, the hydrophobic association interaction has a strong effect on the performance of microspheres such as swelling properties, the rheological performance, and plugging properties. The swelling properties of microsphere studies exhibited the slow swelling rate. The rheological performance measurements showed significant improvements; yield stress, and creep compliance increased rapidly from 404 to 2060 Pa and 3.89 × 10−4 to 1.41 × 10−2 1/Pa, respectively, with DEA content in microspheres rising from 0.0% to 0.22%. The plugging properties of microspheres were enhanced by the slow swelling performance and good viscoelasticity.


2011 ◽  
Vol 236-238 ◽  
pp. 1385-1390 ◽  
Author(s):  
Zhao Yang Yuan ◽  
Hui Ren Hu ◽  
Yang Bing Wen

The glyoxalted polyacrylamide(GPAM) resins were obtained by cross-linking reaction between glyoxal and cationic polyacrylamide(CPAM) through aqueous solution copolymerization. The based CPAM was synthesized with acrylamide(AM) and diallyl dimethyl ammonium chloride(DADMAC) as raw materials by living free radical solution polymerization. Various synthesis conditions were discussed and the optimum conditions for copolymer’s synthesis were as follows: the amount of DADMAC 20%(wt), the charge of the initiator 0.5%(wt), the dosage of chain transfer agent(2-mercaptoethanol) 1.0%(wt), and the charge of crosslinking monomer 9.0%, the dosage of glyoxal 25%(wt), the pH value of the tertiary reaction 7.5-8.0 and the tertiary temperature about 65°C. The structure of the resulting product was characterized by FT-IR, 1H-NMR. Then the GPAM resins were used in the process of paper-making as wet-end additive, the results showed that the paper sheets can get a significant increase in strength properties from the added novel product.


Soft Matter ◽  
2019 ◽  
Vol 15 (47) ◽  
pp. 9640-9646 ◽  
Author(s):  
Marissa A. Morales ◽  
Wynter A. Paiva ◽  
Laura Marvin ◽  
Eva Rose M. Balog ◽  
Jeffrey Mark Halpern

The stimuli-responsive behavior of surface-immobilized ELPs, corresponding to proposed extended and collapsed states, was characterized using electrochemical impedance spectroscopy.


2017 ◽  
Vol 8 (48) ◽  
pp. 7529-7536 ◽  
Author(s):  
Fei Gao ◽  
Yaohui Xing ◽  
Yuan Yao ◽  
Liuying Sun ◽  
Yao Sun ◽  
...  

A PAA-b-PAzoMA-b-PNIPAM triblock copolymer containing pH, photo and temperature sensitive groups could self-assemble into spherical micelles or vesicles with multi-stimuli responsiveness.


RSC Advances ◽  
2020 ◽  
Vol 10 (72) ◽  
pp. 44387-44396
Author(s):  
Hanyu Chen ◽  
Duojiao Fu ◽  
Xiqin Zhou ◽  
Hongqin Liu ◽  
Baocai Xu

The series of gemini amine-oxide surfactants with the formula CnH2n+1CONH(CH2)2N+O–(CH3)–(CH2)3–(CH3)N+O– (CH2)2NHCOCnH2n+1 (n = 11, 13, 15, and 17) have been synthesized, and their pH-stimuli responsive behavior in aqueous solution has been studied.


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