Sustainable Cement-Free Soil Stabilization via a Mussel Mimicry, Water-Resistant Hydrogel

Abstract

Employing hydrogels as a substitute for cement in soil stabilization is believed to have great environmental benefits. However, current hydrogel soil stabilizers cannot function properly in wet conditions due to swelling-induced structural deformation and mechanical weakening, which significantly limits their applications. To overcome current technical limitations and achieve sustainable cement-free soil stabilization, we developed a water-resistant hydrogel soil stabilizer that worked under both dry and wet conditions inspired by the mussel byssal. Carefully formulated precursors containing methacrylic acid and acrylamide were poured into soils and cured via in-site polymerization. The synergic effect of intermolecular hydrogen bonding and hydrophobic interactions led to the formation of heterogeneous mussel mimicry microstructures that possessed superior toughness (up to 2.1 MJ/m3) and ultra-low swelling ratios. Soils strengthened with such hydrogels maintained great strength (up to 2.9 MPa) in both air and water, which had never been achieved before. The intrinsic water affinity of hydrogels also ensured a decent permeability and retention ability of water, which was critical to the ecosystems. In conclusion, a tough, water-resistant, and multi-functional mussel mimicry hydrogel has been devised. It holds great promise as the next-generation cement-free, ecofriendly, and sustainable soil stabilizers.

Negative swelling hydrogel enabled by osmotic pressure induced dehydration

“…It had been proved that acrylamide was able to form strong hydrogen bonding with acrylic acid and its derivatives, which might also induce polymer self-assembly (13,51). However, such systems showed no NS capability (fig.…”

“…The strength of hydrogels dropped dramatically upon swelling due to the dilution of solid matter, leading to reduced performance and structural destruction (9,10). Positive swelling can also induce residue stress in the material, causing buckling, wrinkles and other morphological deformations (11)(12)(13). Without altering the intrinsic trend of swelling, those drawbacks will not be effectively addressed.…”

Amino acid-induced rapid gelation and mechanical reinforcement of hydrogels with low-hysteresis and self-recoverable and fatigue-resistant properties

“…Due to their highly adjustable physical and chemical properties, hydrogels have shown important applications in many fields, such as tissue engineering scaffolds, 1 flexible electronic sensors, 2 absorbents in waste management, 3 oil displacement agents 4 and soil stabilizers. 5 Nevertheless, conventional hydrogels suffer from a complex and time-consuming manufacturing process that usually requires the assistance of external stimuli including long-time UV irradiation, heating and toxic initiators. Moreover, they are usually weak and fragile.…”

A Soft, Adhesive Self‐Healing Naked‐Eye Strain/Stress Visualization Patch

“…Conventionally, the strain and stress of a sample is recorded by universal testing machines. [ 1,2 ] However, this popular approach has many limitations. The sample needs to be cast into standard shapes in order to obtain accurate results.…”