Super Adhesive MXene‐based Nanocomposite Hydrogel with Self‐Healable and Conductivity Properties via Radiation Synthesis

Abstract

Hydrogels are 3D crosslinked hydrophilic polymer networks with a large quantity of water, [1][2][3] which have been applied to a wide range of fields such as chemical sensors, water treatment, human-machine interface, electronic skin, and biomedical engineering in recent decades. [4][5][6][7][8][9] However, the weak mechanical performances of hydrogels made a great challenge for their further applications. [10][11][12] With the exploration of advanced engineering methods and novel materials, as well as structural composition precision design and fillers, an increasing number of functional hydrogels with tunable properties have been prepared, which exhibited the desired mechanical, adhesive, and conductive properties for practical applications. [13][14][15][16][17] Among the functional hydrogels, adhesive hydrogels have attracted much attention for wound healing, soft tissue reconstruction, antibiosis, and wearable electronic devices. [18][19][20][21][22] The polymeric network of hydrogel connects to the substrate materials through covalent bonds, noncovalent complexes, polymer chains, and nanoparticles. A unifying principle has been demonstrated that strong hydrogel adhesion is achieved through the synergy of chemistry, topology, and mechanics. [23] Many strategies were developed to achieve strong adhesion, including the introduction of nanoparticles. [24,25] The nanoparticles can attach to polymer chains by physical or chemical interactions to form a network in nanocomposite hydrogels, which contribute to offering energy dissipation, lowering adhesion energy, and improving the mechanical property. [26] Besides that, some special functional groups on the nanoparticles are beneficial for hydrogel adhesion. [27] In contrast, the incorporation of nanofillers could improve the conductive, [28][29][30] self-healing, stimuli-responsive properties of hydrogels. [31,32] Many nanomaterials were used in nanocomposite adhesive hydrogels such as graphene oxide, [22] silica nanoparticles, [33] iron oxide, [34] and modified carbon nanotubes. [35] In recent years, MXenes-based nanocomposite adhesive hydrogels have attracted more attention. [36] MXenes are emerging 2D transition metal carbides and/or nitrides with a general formula of M nþ1 X n T x . [37][38][39] Ti 3 C 2 T x is the first reported kind of MXenes, which was fabricated by Naguib in 2011. [40] Recently, MXenes have been widely explored due to their remarkable hydrophilic, strong mechanical, and highly conductive properties, [41,42] as well as their high specific surface area and abundant surface-terminating functional groups. [43,44] The unique combination of properties makes MXenes as attractive candidates as nanofillers for nanocomposite

3D Printing of Stretchable, Adhesive and Conductive Ti3C2Tx-Polyacrylic Acid Hydrogels

“…During the soaking process, a redox reaction between the reductive (Ti 3 C 2 T x nanosheets) and the initiator (APS) results in plenty of sulfate radical ( ) generated from APS. Subsequently, hydrolyzes a large amount of hydroxyl radicals ( ), which accelerates the polymerization of AA monomers or oligomers to form PAA chains [ 10 , 35 ]. Meanwhile, the redox reaction releases enormous heat, also facilitating the generation of free radicals for faster cross-linking [ 35 , 36 ].…”

“…Hydrogels have been extensively explored in bioelectronics because of their tissue-like mechanical properties and tunable functionalities. Most recently, an increasing number of functional hydrogels have been employed for the fabrication/integration of bioelectronic devices [ 6 , 7 , 10 ]. Among them, stretchable, adhesive, and conductive hydrogels have been regarded as ideal candidates in human-machine interfaces [ 11 ].…”

Recent Advances in Smart Hydrogels Prepared by Ionizing Radiation Technology for Biomedical Applications

“…Hu et al prepared MXene-based nanocomposite hydrogels using 2-(dimethylamino) ethyl methacrylate (DMAEMA) and ultra-low content Ti 3 C 2 T x MXene nanosheets as the main materials [ 66 ]. DMAEMA was cross-linked into polymers by gamma radiation.…”

Functional adhesive hydrogels for biological interfaces

“…Therefore, hydrogels with physical crosslinks (e.g. hydrogen bonds 108 and van der Waals forces 109 ) or dynamic chemical crosslinks (e.g. Schiff base reaction 110 and boronic ester bonds 111 ) are widely used to develop self‐healing functions 21 …”