Mechanically strong conducting hydrogels with special double-network structure

Dai, Tingyang; Qing, Xutang; Zhou, Hui; Shen, Chen; Wang, Jing; Lu, Yun

doi:10.1016/j.synthmet.2010.01.024

Cited by 72 publications

(60 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, PEDOT:PSS composite hydrogels (water content, 75-90%) exhibited values in the range of 0.67-2.6 mS/cm depending on the conducting polymer content. 9,10 Similar electrical conductivity values were obtained for hydrogels consisting of polyacrylate and a conducting polymer. 12,14 Higher values (>4.3 mS/cm) have been reported, but this usually requires different synthesis strategies, 11 or using hydrogels that consist of solely the conducting polymer, that is without a polymer matrix.…”

supporting

confidence: 61%

“…6 As nonionic hydrogels are not natively electrically conductive, researchers have used various approaches to increase the electrical conductivity of hydrogels by adding salt, 1,3 doping with strong acids, 7 and incorporating conducting fillers such as conducting polymers such as poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). [8][9][10] In addition, it is well known that the swelling ratio (wet mass divided by dry mass) or water content of hydrogels has an important effect on the mechanical and electrical characteristics of hydrogels. 11 For example, it has been shown that the electrical conductivity of double network hydrogels incorporated with a conducting polymer (PEDOT) is inversely proportional to the swelling ratio.…”

mentioning

confidence: 99%

“…These approaches include alternating and direct current measurement techniques such as electrical impedance, conductivity meters, and four-point probe methods. [8][9][10]12,13 Overall, there are a number of differences between these methods. For instance, conductivity meters evaluate the impedance using an alternating current at a single frequency, whereas four-point methods use a direct current, which is applied to the surface.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Electrical conductivity, impedance, and percolation behavior of carbon nanofiber and carbon nanotube containing gellan gum hydrogels

Warren

Gately

O'Brien

et al. 2014

J Polym Sci B Polym Phys

View full text Add to dashboard Cite

The electrical impedance behavior of gellan gum (GG), GG-carbon nanotube, and GG-carbon nanofiber hydrogel composites is reported. It is demonstrated that the impedance behavior of these gels can be modeled using a Warburg element in series with a resistor. Sonolysis (required to disperse the carbon fillers) does not affect GG hydrogel electrical conductivity (1.2 6 0.1 mS/cm), but has a detrimental effect on the gel's mechanical characteristics. It was found that the electrical conductivity (evaluated using impedance analysis) increases with increasing volume fraction of the carbon fillers and decreasing water content. For example, carbon nanotube containing hydrogels exhibited a six-to sevenfold increase in electrical conductivity (to 7 6 2 mS/cm) at water content of 82%. It is demonstrated that at water content of 95 6 2% the electrical behavior of multiwalled nanotube containing hydrogels transitions (percolates) from transport dominated by ions (owing to GG) to transport dominated by electrons (owing to the carbon nanotube network).

show abstract

supporting

confidence: 61%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Electrical conductivity, impedance, and percolation behavior of carbon nanofiber and carbon nanotube containing gellan gum hydrogels

Warren

Gately

O'Brien

et al. 2014

J Polym Sci B Polym Phys

View full text Add to dashboard Cite

show abstract

“…In one study, PEDOT-PSS was chemically polymerized within polyacrylamide (PAAm). 27 The achieved PAAm-PEDOT-PSS hydrogels were tough with compression strength as high as 1.3 MPa, fracture strain of 60−90%, and electrical conductivity on the order of 1 × 10 −3 S cm −1 . The maximum conductivity that could be achieved in this example was limited by the solubility of EDOT monomer in the aqueous solution of PSS.…”

Section: ■ Introductionmentioning

confidence: 99%

Electrically Conductive, Tough Hydrogels with pH Sensitivity

et al. 2012

View full text Add to dashboard Cite

Electrically conductive, mechanically tough hydrogels based on a double network (DN) comprised of poly(ethylene glycol) methyl ether methacrylate (PPEGMA) and poly(acrylic acid) (PAA) were produced. Poly(3,4-ethylenedioxythiophene) (PEDOT) was chemically polymerized within the tough DN gel to provide electronic conductivity. The effects of pH on the tensile and compressive mechanical properties of the fully swollen hydrogels, along with their electrical conductivity and swelling ratio were determined. Compressive and tensile strengths as high as 11.6 and 0.6 MPa, respectively, were obtained for hydrogels containing PEDOT with a maximum conductivity of 4.3 S cm -1 . This conductivity is the highest yet reported for hydrogel materials of high swelling ratios. These hydrogels may be useful as soft strain sensors because their electrical resistance changed significantly when cyclically loaded in compression. ABSTRACT: Electrically conductive, mechanically tough hydrogels based on a double network (DN) comprised of poly(ethylene glycol) methyl ether methacrylate (PPEGMA) and poly(acrylic acid) (PAA) were produced. Poly(3,4-ethylenedioxythiophene) (PEDOT) was chemically polymerized within the tough DN gel to provide electronic conductivity. The effects of pH on the tensile and compressive mechanical properties of the fully swollen hydrogels, along with their electrical conductivity and swelling ratio were determined. Compressive and tensile strengths as high as 11.6 and 0.6 MPa, respectively, were obtained for hydrogels containing PEDOT with a maximum conductivity of 4.3 S cm −1 . This conductivity is the highest yet reported for hydrogel materials of high swelling ratios. These hydrogels may be useful as soft strain sensors because their electrical resistance changed significantly when cyclically loaded in compression.

show abstract

“…Conducting hydrogels (CH) are a class of composites which combine the electrochemical functionality of CPs with the loading capacity and mechanical properties of hydrogels. [67][68][69][70][71][72][73][74][75][76][77][78][79] CHs have mechanical properties akin to that of neural tissue, reducing the strain mismatch at the neural interface which is a contributing factor to the chronic inflammatory response upon implantation. [67][68][69][70][71][72][73][74] Several different approaches to the fabrication of CHs have been investigated, the most common approach being the electrochemical deposition of CP within a pre-formed hydrogel matrix.…”

Section: Biological Propertiesmentioning

confidence: 99%

Small bioactive molecules as dual functional co-dopants for conducting polymers

et al. 2015

View full text Add to dashboard Cite

Biological responses to neural interfacing electrodes can be modulated via biofunctionalisation of conducting polymer (CP) coatings. This study investigated the use of small bioactive molecules with anti-inflammatory properties. Specifically, anionic dexamethasone phosphate (DP) and valproic acid (VA) were used to dope the CP poly(ethylenedioxythiophene) (PEDOT). The impact of DP and VA on material properties was explored both individually and together as a codoped system, compared to the conventional dopant p-toluenesulfonate (pTS). Electrical properties of DP and VA doped PEDOT were reduced in comparison to PEDOT/pTS, however co-doping with both DP and VA was shown to significantly improve the electroactivity of PEDOT in comparison the individually doped coatings.Similarly, while the individually doped PEDOT coatings were mechanically friable, the inclusion of both dopants during electropolymerisation was shown to attenuate this response. In a whole-blood model of inflammation all DP and VA doped CPs retained their bioactivity, causing a significant reduction in levels of the pro-inflammatory cytokine TNF-a. These studies demonstrated that small charged bioactive molecules are able act as dopants for CPs and that co-doping with ions of varied size and doping affinity may provide a means of addressing the limitations of large bulky bimolecular dopants. Fig. 2 SEM micrographs of PEDOT coatings doped with (clockwise from top left) pTS, DP, DP + VA and VA taken at 2500Â magnification.

show abstract

Mechanically strong conducting hydrogels with special double-network structure

Cited by 72 publications

References 17 publications

Electrical conductivity, impedance, and percolation behavior of carbon nanofiber and carbon nanotube containing gellan gum hydrogels

Electrical conductivity, impedance, and percolation behavior of carbon nanofiber and carbon nanotube containing gellan gum hydrogels

Electrically Conductive, Tough Hydrogels with pH Sensitivity

Small bioactive molecules as dual functional co-dopants for conducting polymers

Contact Info

Product

Resources

About