The role of sulfonate groups and hydrogen bonding in the proton conductivity of two coordination networks

• Ali Javed,
• Felix Steinke,
• Stephan Wöhlbrandt,
• Hana Bunzen,
• Norbert Stock and
• Michael Tiemann

Beilstein J. Nanotechnol. 2022, 13, 437–443, doi:10.3762/bjnano.13.36

• , Germany 10.3762/bjnano.13.36 Abstract The proton conductivity of two coordination networks, [Mg(H2O)2(H3L)]·H2O and [Pb2(HL)]·H2O (H5L = (H2O3PCH2)2-NCH2-C6H4-SO3H), is investigated by AC impedance spectroscopy. Both materials contain the same phosphonato-sulfonate linker molecule, but have clearly

• different crystal structures, which has a strong effect on proton conductivity. In the Mg-based coordination network, dangling sulfonate groups are part of an extended hydrogen bonding network, facilitating a “proton hopping” with low activation energy; the material shows a moderate proton conductivity. In

• the Pb-based metal-organic framework, in contrast, no extended hydrogen bonding occurs, as the sulfonate groups coordinate to Pb2+, without forming hydrogen bonds; the proton conductivity is much lower in this material. Keywords: coordination network; coordination polymer; impedance spectroscopy

A comprehensive review on electrospun nanohybrid membranes for wastewater treatment

• Senuri Kumarage,
• Imalka Munaweera and
• Nilwala Kottegoda

Beilstein J. Nanotechnol. 2022, 13, 137–159, doi:10.3762/bjnano.13.10

• alone [12]. In addition, ENHs have been utilized in energy applications as well. Zhang et al. developed a graphene oxide (GO)-based nanohybrid Nafion nanofiber as a proton-exchange membrane (PEM) for fuel cells to overcome low proton conductivity, high fuel permeability, and poor stability of

BTEX detection with composites of ethylenevinyl acetate and nanostructured carbon

• Santa Stepina,
• Astrida Berzina,
• Gita Sakale and
• Maris Knite

Beilstein J. Nanotechnol. 2017, 8, 982–988, doi:10.3762/bjnano.8.100

• measurements [21]. In near 100% relative humidity proton conductivity dominates over the tunnelling current conduction mechanism typical for polymer–carbon nano-filler composites. This proves that sensing measurements do not increase with increased humidity, but the full mechanism is still unknown. The aim of

First examples of organosilica-based ionogels: synthesis and electrochemical behavior

• Andreas Taubert,
• Ruben Löbbicke,
• Barbara Kirchner and
• Fabrice Leroux

Beilstein J. Nanotechnol. 2017, 8, 736–751, doi:10.3762/bjnano.8.77

• : ionic liquids; ionogels; organosilica; proton conductivity; Introduction Ionic liquids (ILs), that is, substances solely composed of ionic species have been studied for virtually every application from organic synthesis to lubrication and battery technology [1][2][3][4]. A particularly promising field

• two sulfonate groups share a proton and are thus expected to enhance proton conductivity, identical to the previous example [25]. The combination of [BmimSO3H][PTS] with the organosilicas described above yields IGs with the shapes and dimensions of the respective organosilica matrix. In touching the

Materials and characterization techniques for high-temperature polymer electrolyte membrane fuel cells

• Roswitha Zeis

Beilstein J. Nanotechnol. 2015, 6, 68–83, doi:10.3762/bjnano.6.8

• exhibit high proton conductivity in low-hydration and even anhydrous states. Of special concern for phosphoric-acid-doped PBI-type membranes is the acid loss and management during operation. The slow oxygen reduction reaction in HT-PEMFCs remains a challenge. Phosphoric acid tends to adsorb onto the

• the water content is a delicate task for LT-PEMFCs. In comparison, HT-PEMFCs are far more forgiving regarding the water management. Acid-based PBI-type membranes exhibit a high proton conductivity even in an anhydrous state. Therefore, additional humidification of the gas feeds is not needed

• here are applicable to other types of HT-PEMFCs as well. Review Materials for HT-PEMFCs Phosphoric-acid-doped polybenzimidazole-type membranes Nafion® (DuPont), the most prominent member of the PFSA membrane group, exhibits an extremly high proton conductivity of up to 0.1 S·cm−1 under fully hydrated

Large-scale atomistic and quantum-mechanical simulations of a Nafion membrane: Morphology, proton solvation and charge transport

• Pavel V. Komarov,
• Pavel G. Khalatur and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 567–587, doi:10.3762/bjnano.4.65

• observe the bimodality of the van Hove autocorrelation function, which provides the direct evidence of the Grotthuss bond-exchange (hopping) mechanism as a significant contributor to the proton conductivity. Keywords: atomistic simulation; morphology; Nafion membrane; proton transport; quantum molecular

• nanochannels embedded in the matrix. The details of this process and the organization of the nanochannels are not well understood at the present time. It is assumed that the walls of the hydrophilic channels contain mainly dissociated sulfonic acid groups and their counter ions enabling proton conductivity of

• current literature (see, for example [5][6][7][8][9][10][11][12]). The importance of optimizing the morphology becomes clear in the following example. In order to achieve high proton conductivity, the molecular structure should be such that the hydrated membrane contains wide interconnected water channels

Novel composite Zr/PBI-O-PhT membranes for HT-PEFC applications

• Mikhail S. Kondratenko,
• Igor I. Ponomarev,
• Marat O. Gallyamov,
• Dmitry Y. Razorenov,
• Yulia A. Volkova,
• Elena P. Kharitonova and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 481–492, doi:10.3762/bjnano.4.57

• with Zr facilitated an increase of the phosphoric acid (PA) uptake by the membranes, which resulted in an up to 2.5 times increased proton conductivity. The existence of an optimal amount of Zr content in the modified PBI-O-PhT film was shown. Larger amounts of Zr lead to a lower PA doping level and a

• improved in order to make HT-PEFC economically reasonable. The proton conductivity of PBI membranes generally increases with the PA doping level [1]. At the same time, higher PA doping levels usually result in decreased mechanical strength, which may lead to an increased crossover of reactant gases. The

• design of an advanced membrane for HT-PEFC applications necessitates the finding of an appropriate compromise between proton conductivity on the one hand and good mechanical properties as well as low gas permeability on the other hand. Various PBI-based composites have been proposed in order to achieve

Zeolites as nanoporous, gas-sensitive materials for in situ monitoring of DeNO_x-SCR

• Thomas Simons and
• Ulrich Simon

Beilstein J. Nanotechnol. 2012, 3, 667–673, doi:10.3762/bjnano.3.76

• measurements were performed in order to measure the temporal evolution of the proton conductivity while the samples were kept at constant temperatures between 85 and 200 °C, after they have been loaded with NH3 for 45 min. After NH3 loading, the gas atmosphere was switched to N2, and the absolute value of the

Distribution of functional groups in periodic mesoporous organosilica materials studied by small-angle neutron scattering with in situ adsorption of nitrogen

• Monir Sharifi,
• Dirk Wallacher and
• Michael Wark

Beilstein J. Nanotechnol. 2012, 3, 428–437, doi:10.3762/bjnano.3.49

• -groups; such material shows a high proton conductivity [27] and has potential to create proton-conducting hybrid membranes for applications in fuel cells [28][29], electrodialysis for water purification [30], or photoelectrochemical cells for water splitting with solar light in order to separate the