Abstract: Fe₃O₄ nanoparticles were used as stabilizer and emulsifier to prepare Pickering-type ASA (alkenyl succinic anhydride) emulsions, and the effects of particles concentration, volume ratio of oil/water and pH value on the type, stability, morphology and sizing performance of the emulsions were investigated. Fe₃O₄ nanoparticles were able to emulsify ASA to prepare homogeneous emulsions. When emulsions were placed without stirring at room temperature, the separated oil phase fraction increased with increasing particles concentration and decreased with increasing volume ratio of oil/water. Emulsions could keep homogeneous phase for 6 h as volume ratio of oil/water was 2 and particles concentration was 0.1%(mass). For stable emulsions, part of particles was absorbed at liquid-liquid interface and part of particles entered the dispersed phase, the stability of emulsions reduced with increasing particles concentration. Before the emulsions creamed, hydrolysis resistance was investigated and ASA was partially hydrolyzed. Sheet surface contact angle gradually increased by adding emulsions which were placed for 1 h, meanwhile surface roughness were decreased. When addition of ASA was 1.0%(mass relative to the absolute dry pulp), sheet surface contact angle reached 93.5? and surface roughness was 15.924 mm.

Key words: Fe₃O₄ nanoparticles, Pickering emulsions, ASA, stability, hydrolysis, sizing performance

摘要： 利用纳米Fe₃O₄作为稳定剂和乳化剂来制备Pickering型ASA（alkenyl succinic anhydride） 施胶乳液，并研究了固体颗粒浓度、油水比、水分散相pH对乳液类型、稳定性、形态及施胶性能的影响。结果表明，纳米Fe₃O₄能够乳化制备均一稳定的Pickering型ASA乳液。乳液在室温下静置稳定，析出油相体积分数随固体颗粒用量的增加而增大，随油水比的增大而减小。油水比为2：1，水分散相浓度为0.1%（质量分数）时制备的ASA乳液稳定性最佳。固体颗粒部分吸附在油/水界面处，部分分散在分散相中，随分散相中固体颗粒浓度的增加，乳液稳定性变差。乳液静置分层之前，ASA发生部分水解。在放置1 h后用于纸页浆内施胶，随ASA乳液用量的增加，纸页表面接触角逐渐增大，且纸页表面粗糙度下降。在ASA的添加量为1.0%（质量分数）时，纸页表面接触角达到93.5°，纸页表面粗糙度为15.924 μm。

关键词: 纳米Fe₃O₄, Pickering乳液, ASA, 稳定性, 水解, 施胶性能