Abstract Due to various industrial applications, aqueous foams stabilized by surfactants in combination without and with polymers, biopolymers or/and solid particles have been extensively investigated. In contrast, there are few reports involved in surfactant-free aqueous foams. Herein, a surfactant-free foam system containing xanthan-based amphiphilic polysaccharide (C8-g-XG) and nanosilica particle was presented and studied. With an attempt to address the framework, C8-g-XG was prepared via n-octylamine grafted onto xanthan gum (XG). C8-g-XG inherited good viscosification, salt tolerance and temperature resistance from XG, and lower values of γCMC (39.2 mN/m) appeared in C8-g-XG solutions. Additionally, the surface tension of C8-g-XG solutions (3000 mg/L) with 0.2 wt% nanosilica particles would not change significantly. However, C8-g-XG@nanosilica particle-stablized foams exhibited excellent thermal adaptability, thermal stability and proppant suspension ability due to synergy of C8-g-XG and nanosilica particles. As a result, this strategy may be used to develop eco-friendly low formation-injury foam fluids for hydraulic fracturing application because C8-g-XG could be degraded and its surface activity was disabled.

中文翻译：

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无表面活性剂的水性泡沫通过黄原胶基两亲生物聚合物和纳米颗粒的协同作用而稳定，作为潜在的水力压裂液

摘要 由于各种工业应用，已经广泛研究了由表面活性剂与聚合物、生物聚合物或/和固体颗粒的组合稳定的水性泡沫。相比之下，关于不含表面活性剂的水性泡沫的报道很少。在此，提出并研究了一种含有黄原胶基两亲性多糖 (C8-g-XG) 和纳米二氧化硅颗粒的无表面活性剂泡沫体系。为了解决框架问题，C8-g-XG 是通过将正辛胺接枝到黄原胶 (XG) 上制备的。C8-g-XG 继承了 XG 良好的增粘、耐盐和耐温性，在 C8-g-XG 溶液中出现了较低的 γCMC (39.2 mN/m)。此外，含有 0.2 wt% 纳米二氧化硅颗粒的 C8-g-XG 溶液 (3000 mg/L) 的表面张力不会发生显着变化。然而，由于C8-g-XG和纳米二氧化硅颗粒的协同作用，C8-g-XG@纳米二氧化硅颗粒稳定泡沫表现出优异的热适应性、热稳定性和支撑剂悬浮能力。因此，该策略可用于开发用于水力压裂应用的环保低地层伤害泡沫流体，因为 C8-g-XG 可能会被降解并且其表面活性被禁用。