# Polyzwitterionic Organohydrogel and Soft Composite with Tunable Sol–Gel Properties Enabling On‐Demand Functionalization with Colloids

## TL;DR

This paper introduces a new type of stretchable, self-healing organohydrogel that can be tuned to respond to mechanical and magnetic stimuli for use in soft robotics and sensing.

## Contribution

A novel polyzwitterionic organohydrogel platform with tunable sol–gel properties and on-demand functionalization with colloids is introduced.

## Key findings

- PDMAPS organohydrogels show ultrahigh stretchability, self-adhesion, and remoldability.
- MXene-integrated composites enable strain-tunable electromagnetic interference shielding.
- NdFeB microparticle composites act as mechano–magneto–electric transducers for strain detection and haptic feedback.

## Abstract

While zwitterionic hydrogels and aq. polymers have already been used in, e.g., bio‐related, environmental, and ionic transport‐related applications, it is foreseen that their characteristic ability of zwitterions to bind functional particles combined with sol–gel transitions can allow emerging potential for responsive soft composites. Here, it is first shown that polyzwitterionic poly[2‐(methacryloyloxy)ethyl]dimethyl‐(3‐sulfopropyl)ammonium hydroxide (PDMAPS), allows organohydrogelation upon adding dimethyl sulfoxide to its aqueous solution, inducing phase‐separations to form physical cross‐links. Density functional theory (DFT) analysis reveals solvent–polymer interactions that drive the organohydragelation. The organohydrogels exhibit ultrahigh stretchability (>2800%), quick self‐adhesion, remoldability, and tunable viscoelasticity. By modulating solvent composition and integrating functional fillers, distinct sol‐ and gel‐like states are achieved on‐demand. In the sol‐like state, titanium carbide nanosheets (MXenes)‐incorporated PDMAPS soft composite enable mechano‐tunable electromagnetic interference shielding via nanosheet reorientation under strain. In the gel‐like regime, incorporation of magneticneodymium iron boron magnet (NdFeB) microparticles yields mechano–magneto–electric transducers for strain detection, dynamic haptic functionality, as demonstrated by Morse code encoding, and high durability in repeated compressive cycles. This work introduces a versatile organohydrogel platform with tunable viscoelastic properties, suitable for on‐demand functionalized soft composites, suggesting new design principles for transducing, sensing, and soft robotics.

Poly[2‐(methacryloyloxy)ethyl]dimethyl‐(3‐sulfopropyl)ammonium hydroxide‐based organohydrogels are formed via nonsolvent‐induced gelation, featuring tunable viscoelasticity. Functional fillers (MXene nanosheets, magnetic NdFeB microparticles) enable electrical, magnetic, and mechanical responsiveness for applications in mechano‐tunable electromagnetic interference shielding and mechano–magneto–electric transducers for strain sensing, offering a versatile platform for adaptive, multifunctional soft composites.