Unprecedented Acid‐Promoted Polymerization and Gelation of Acrylamide: A Serendipitous Discovery

Abstract

Dilute acid polymerizes degassed, aqueous acrylamide with concomitant gelation, without the need for added free radical initiator or cross-linking agent. This reaction is accelerated by sonication or UV irradiation, but inhibited by adventitious oxygen or the addition of a free radical inhibitor, suggesting an acid-accelerated free radical process. The resulting hydrogels are thixotropic in nature and partially disrupted by the addition of chaotropic agents, indicating the importance of hydrogen bonding to the 3D network. This discovery was made while trying to prepare pectin-polyacrylamide hydrogels. We observed that pectin initiated the gelation of acrylamide, but only if the aqueous pectin samples had a pH lower than ca. 5.

Ultrahigh Conductive and Stretchable Eutectogel Electrolyte for High-Voltage Flexible Antifreeze Quasi-solid-state Zinc-Ion Hybrid Supercapacitor

“…As shown in Figure b, there is no noticeable shift in the characteristic bands of ClO 4 – and AM as water content increases, illustrating that various water contents do not deteriorate the property of the ionic liquid. , Meanwhile, the faint characteristic peak of H 2 O (3200–3400 cm –1 ) indicates low free water activity, and probably most of the water molecules are involved in the interactions with DES components such as acrylamide and salt ions . In addition, the hydrogen bonds in water are mitigated owing to competitive Zn 2+ -O interactions and weak ClO 4 – -H 2 O hydrogen bonds . Thus, the ZHSC formed in situ (Figure c) exhibits a high voltage window of 2.2 V. The Zn-PAM-H 2 O eutectogel morphology was obtained by SEM.…”

Tunable Metallogels Based on Bifunctional Ligands: Precursor Metallogels, Spinel Oxides, Dye and CO2 Adsorption

“…The obtained product was purified by washing with 50 mL of 5% HCl followed by 20 mL of water, 20 mL of methanol, and finally with ether. For LMWG1, 1 H NMR (DMSO-d 6 , δ ppm): 13.32 (broad peak, 4H, COOH), 10.76 Metallogel Synthesis. In this work, we have adopted the reported synthetic technique for metallogel preparation.…”

“…The semisolid gel materials are a gift of serendipity via various chemical interactions. 1 These materials are loaded with immobilized solvents like dimethyl sulfoxide, 2 N , N -dimethyl formamide, 3 , 4 dichloromethane, 5 tetrahydrofuran, 6 water, 7 methanol, and ethanol 8 into their inorganic or organic gel matrixes. 9 The self-assembled semisolid gel materials derived from the low-molecular-weight gelator are called metallogels in the presence of a metal ion, otherwise termed as organogels.…”

“…In recent years, soft materials attracted plenty of attention due to their astonishing capabilities in the copious facets of life. The semisolid gel materials are a gift of serendipity via various chemical interactions . These materials are loaded with immobilized solvents like dimethyl sulfoxide, N , N -dimethyl formamide, , dichloromethane, tetrahydrofuran, water, methanol, and ethanol into their inorganic or organic gel matrixes .…”

Development of Supramolecular Semiconducting Mn(II)-Metallogel Based Active Device with Substantial Carrier Diffusion Length

“…The rational design of gels is still a challenging task as most of the potential gelators are the outcome of serendipity. 41 Several supramolecular interactions such as hydrogen bonding, electrostatic, hydrophobic, hydrophilic, van der Waals forces, aryl-system based interactions, etc. play an important role in supramolecular gel formation.…”