Synthesis of conductive doubly filled poly(N-isopropylacrylamide)-polyaniline-SiO2 hydrogels

Depa, Katarzyna; Strachota, Adam; Šlouf, Miroslav; Brus, Jiřı́; Cimrová, Věra

doi:10.1016/j.snb.2016.12.121

Cited by 37 publications

(29 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Poly( N ‐isopropylacrylamide) (PNIPA) is one of the most studied thermosensitive polymers . The hydrogels based on crosslinked PNIPA display a volume phase transition at around 32 °C and have potential applications in numerous fields, including drug delivery systems, actuators and sensors and enzyme immobilization . A drawback of these hydrogels is their limited extensibility and hence brittleness, because of their inhomogeneous polymer network structure .…”

Section: Introductionmentioning

confidence: 99%

Tremendous reinforcing, pore-stabilizing and response-accelerating effect of in situ generated nanosilica in thermoresponsive poly(N -isopropylacrylamide) cryogels

Šlouf

Matějka

2017

Polym. Int

Self Cite

View full text Add to dashboard Cite

The tremendous reinforcing and pore-stabilizing effect of in situ formed nanosilica in a highly porous temperature-responsive poly(N-isopropylacrylamide) (PNIPA) matrix is demonstrated. A very weakly crosslinked semi-liquid hydrogel can be reinforced to the point that it displays a fast, extensive and nearly symmetric temperature-responsiveness in combination with an acceptable modulus. In soft but solid porous PNIPA, only 0.6 wt% of the nanofiller is sufficient to stabilize the pores against collapse upon de-swelling, thus enabling ultrafast responsiveness. A spectacular effect is achieved with dried porous PNIPA (matrix is glassy, T g ≈ 140 ∘ C), which in the case of optimal nanosilica amounts can re-swell in only 3 min. The key importance of efficient hydrogen bridging between PNIPA and SiO 2 is demonstrated by comparing in situ formed nanosilica with similarly sized commercial Ludox particles, the surface of which is saturated with ammonia (for stabilization). Synthesis parameters like the amount of crosslinker and of nanosilica were varied in a wide range, in order to achieve the fastest possible responsiveness of the hydrogels in combination with a high modulus. The porosity, nanosilica distribution, moduli, temperature-dependent swelling as well as the swelling kinetics of the gels were determined as functions of contents of crosslinker and nanosilica.

show abstract

Section: Introductionmentioning

confidence: 99%

Tremendous reinforcing, pore-stabilizing and response-accelerating effect of in situ generated nanosilica in thermoresponsive poly(N -isopropylacrylamide) cryogels

Šlouf

Matějka

2017

Polym. Int

Self Cite

View full text Add to dashboard Cite

show abstract

“…Since nanocomposites often have a photo-thermo conversion ability, nanocomposite hydrogels usually exhibit the improved responsiveness via site-specific deformation. For example, porous doubly filled PNIPAM/SiO /polyaniline hydrogels displayed reversible and 2 symmetrical shape changes in response to temperatures (swelling at 25 °C and deswelling at 50 °C) as fast as 6 s due to the incorporation of nano- 52 SiO . By incorporating graphene oxide (GO) nanosheets, 2 PNIPAM/GO nanocomposite hydrogels also exhibited a different actuation mechanism, in which GO nanosheets enabled to convert NIR light to heat that further induced shape actuation (Fig.…”

Section: Hybrid Nanocomposite Structurementioning

confidence: 99%

Thermo-Responsive and Shape-Adaptive Hydrogel Actuators from Fundamentals to Applications

Zhang¹,

Xie²,

Zhang³

et al. 2019

Eng. Sci.

View full text Add to dashboard Cite

“…This reversible solubility of PNIPAM is attributed to a coil-globule conformational transition of polymer chains [25] [26] [27]. Hence, PNIPAM is applied to not only a drug delivery system [28] [29] and an actuator [30], but also flocculant. In the case of applying PNIPAM to flocculant, it is expected that PNIPAM adsorbs on the surface of soil particles below 32˚C.…”

Section: Introductionmentioning

confidence: 99%

“…NIPAM(2 g) and distilled water (100 mL) were put into a two-necked separable flask and the solution was stirred for 30 min with N 2 bubbling for removing oxygen. After 30 min, 10 mL of APS aqueous solution(5,10,30 mg/mL), which was sonicated for 10 min owing to remove oxygen before use, was added as an initiator and the solution was stirred for 10 min. After that, 10 mL of TMEDA aqueous solution sonicated for 10 min was added as an accelerator and the solution was stirred for 4 h. After the reaction for 4 h, this solution was put into dialysis cellulose membrane (pore size is 50 Å) and dialysis was performed four times for 12 h. Finally, the dialyzed solution was dried at 60˚C Journal of Materials Science and Chemical Engineeringfor 2 days.…”

mentioning

confidence: 99%

The Aggregation of Bentonite Using Poly(N-isopropylacrylamide) as a Flocculant

Nakamura¹,

Murakami²

2018

MSCE

View full text Add to dashboard Cite

Sedimentation tests of bentonite suspension were carried out by adding various concentrations of poly(N-isopropylacrylamide) (PNIPAM) with different molecular weights as flocculant below and above lower critical solution temperature (LCST). Also, the effect of PNIPAM on aggregation of bentonite was investigated by sedimentation rate, turbidity of supernatant. Additionally, XRD patterns and SEM photographs were measured in order to consider aggregation mechanism of PNIPAM. The sedimentation rate and turbidity for the PNIPAM with large molecular weight or PNIPAM solution of high concentration above LCST were faster and clearer than those with small molecular weight or low concentration. From XRD patterns, the peak of bentonite sediment with PNIPAM shifted to the low-angle side, suggesting that a part of PNIPAM chain entered between bentonite layers. Furthermore, it was confirmed by SEM photographs that PNIPAM covered bentonite surface after sedimentation test. It was indicated that PNIPAM adsorbs on the bentonite surface and aggregates each bentonite particle above LCST. From these results, PNIPAM works as a flocculant and the PNIPAM with large molecular weight has a good ability.

show abstract

Synthesis of conductive doubly filled poly(N-isopropylacrylamide)-polyaniline-SiO2 hydrogels

Cited by 37 publications

References 79 publications

Tremendous reinforcing, pore-stabilizing and response-accelerating effect of in situ generated nanosilica in thermoresponsive poly(N -isopropylacrylamide) cryogels

Tremendous reinforcing, pore-stabilizing and response-accelerating effect of in situ generated nanosilica in thermoresponsive poly(N -isopropylacrylamide) cryogels

Thermo-Responsive and Shape-Adaptive Hydrogel Actuators from Fundamentals to Applications

The Aggregation of Bentonite Using Poly(N-isopropylacrylamide) as a Flocculant

Contact Info

Product

Resources

About