Multiscale Interface Design of Carboxylated MWCNTs/CIPs-OH Hybrid Magnetorheological Fluids for Enhanced...

Area of Science:

• Materials Science
• Nanotechnology
• Rheology

Background:

• Magnetorheological fluids (MRFs) face challenges in simultaneously improving rheological performance and sedimentation stability.
• Existing MRFs often exhibit a trade-off between enhanced field-induced properties and long-term stability.

Purpose of the Study:

• To develop a hybrid MRF system that overcomes the limitations of conventional MRFs.
• To enhance both the field-induced rheological response and sedimentation stability of MRFs through multiscale interfacial engineering.

Main Methods:

• Functionalization of carbonyl iron particles (CIPs) with hydroxyl groups (CIPs-OH).
• Incorporation of carboxylated multiwalled carbon nanotubes (MWCNTs) into the MRF.
• Utilizing molecular dynamics simulations and experimental characterization to analyze interfacial interactions.
• Employing mechanical mixing and ultrasonic dispersion for hybrid MRF preparation.

Main Results:

• Stable adsorption of MWCNTs onto CIPs-OH via hydrogen bonding, reinforcing particle chains.
• Enhanced yield stress and reduced loss modulus of the hybrid MRF under magnetic fields.
• MWCNTs form a bridging network in the carrier liquid, suppressing aggregation and improving sedimentation.
• The hybrid MRF demonstrates a superior balance of rheological enhancement and stability compared to conventional MRFs.

Conclusions:

• Multiscale interfacial coupling, particularly through dynamic hydrogen bonding, is effective for designing high-performance MRFs.
• The proposed strategy offers a scalable pathway for creating advanced magnetorheological materials.
• This approach successfully addresses the long-standing trade-off between rheological performance and sedimentation stability in MRFs.