The formulation of photosensitive SiC slurry with high solid loading, low viscosity, and long‐term stability remains a critical challenge. Herein, a triblock copolymer of poly(ethylene glycol)–block–poly(propylene glycol)–block–poly(ethylene glycol) (PEG–PPG–PEG) was employed as a kind of dispersant to modulate the wettability of SiC particle surfaces through hydrogen‐bonding anchoring interactions. The results demonstrate that with the addition of 6 wt % PEG–PPG–PEG, the slurry viscosity reaches a minimum, and the retained sedimentation height after 96 h is as high as 86%, indicating pronounced shear‐thinning behavior and excellent long‐term stability. Furthermore, fine SiC particles were incorporated to construct a particle size grading system, and the effects of particle size grading on slurry stability, rheological properties, and photosensitive properties were systematically investigated. Through the optimized debinding and liquid silicon infiltration (LSI) processes, the fabricated SiC ceramic achieves a density of 2.76 ± 0.01 g/cm3, a flexural strength of 198.21 ± 5.04 MPa, and a Vickers hardness of 27.95 ± 1.66 GPa. A honeycomb‐structured space mirror, printed using the bimodal slurry, exhibits superior surface quality after polishing and delivers clear, undistorted imaging. This work provides a novel strategy and theoretical foundation for enhancing the printability of high‐solid‐loading SiC slurry.
Shulei Xu, Chuanzhen Huang, Hanlian Liu et al.· Journal of The American Cera...· 0 citations
To address the trade-off between friction reduction and proppant suspension in conventional fluids, an aqueous two-phase system comprising nanoparticle-reinforced biopolysaccharideand zwitterionic gel was developed for deep offshore reservoir stimulation. Specifically, xanthan gum (XG) serves as the dispersed phase, while a rehydratable sulfobetaine-type zwitterionic cross-linked gel (poly(sulfobetaine methacrylate)-co-poly(ethylene glycol) diacrylate, PSBMA–PEGDA) synthesized via UV-initiated free radical polymerization followed by lyophilization and ball milling acts as the continuous phase. Silica nanoparticles are subsequently incorporated as a physical cross-linking reinforcing phase to ultimately yield a stable aqueous two-phase system. Comprehensive rheological, ball-on-disk tribological, and static proppant suspension characterizations reveal that the optimized system achieves an interfacial friction reduction efficiency of 82%, outperforming its single-phase counterpart by 41.3%. Furthermore, it exhibits a static proppant suspension duration exceeding 36 h, substantially outperforming that of conventional single-phase XG system (∼5.8 h). The friction reduction mechanism is primarily governed by the synergistic effect between the elastic kinetic energy dissipation of the semirigid XG network and the zwitterionic hydration lubrication layer. This robust proppant suspension capacity is attributed to the high-yield-stress 3D hybrid network, which is formed through the spatial interpenetration of the XG double-helical scaffold and PSBMA–PEGDA microdomains, and further fortified by silica nanoparticles acting as physical cross-linking nodes. Consequently, this aqueous two-phase system emerges as a highly functional fracturing fluid material, integrating superior friction reduction and proppant suspension properties for the reservoir stimulation of deep offshore oilfields.
Changlong Liu, Yunpeng Zhang, Fengming Liu et al.· Langmuir· 0 citations
