Janus amphiphilic polymer nanosheets(JAPNs)with anisotropic morphology and distinctive perfor-mance have aroused widespread interest.However,due to the difficulty in synthesis and poor dispersion stability,JAPNs have ...Janus amphiphilic polymer nanosheets(JAPNs)with anisotropic morphology and distinctive perfor-mance have aroused widespread interest.However,due to the difficulty in synthesis and poor dispersion stability,JAPNs have been scarcely reported in the field of enhancing oil recovery(EOR).Herein,a kind of organic-based flexible JAPNs was prepared by paraffin emulsion methods.The lateral sizes of JAPNs were ranging from hundreds of nanometers to several micrometers and the thickness was about 3 nm.The organic-based nanosheets were equipped with remarkably flexible structures,which could improve their injection performance.The dispersion and interfacial properties of JAPNs were studied systematically.By modification of crosslinking agent containing multiple amino groups,the JAPNs had excellent hydro-philicity and salt resistance compared with conventional inorganic or composite nanosheets.The settling time of nanosuspension with NaCl and CaCl_(2) at a low salinity of 1000 mg/L was over 240 h.The value could also remain 124 h under the salinity of 10,000 mg/L NaCl.With the dual functionalities of Janus amphiphilic nature and nanoparticles'Pickering effect,JAPNs could change rock wettability and form emulsions as"colloidal surfactants",In particular,a new technology called optical microrheology was pioneered to explore the destabilization state of nanosuspensions for the first time.Since precipitation lagged behind aggregation,especially for stable suspension systems,the onset of the unstable behavior was difficult to be detected by conventional methods,which should be the indicator of reduced effec-tiveness for nanofluid products.In addition,the oil displacement experiments demonstrated that the JAPNs could enhance oil recovery by 17.14%under an ultra-low concentration of 0.005%and were more suitable for low permeability cores.The findings can help for a better understanding of the material preparation of polymer nanosheets.We also hope that this study could shed more light on the nano-flooding technology for EOR.展开更多
背景:Janus微/纳米颗粒因具有形状、结构、功能各向异性被广泛应用于组织工程、药物递送、癌症治疗、生物影像和传感等医学领域。目的:阐述Janus微/纳米颗粒在生物医学的前沿应用。方法:通过计算机检索中国知网、万方、PubMed、Web of S...背景:Janus微/纳米颗粒因具有形状、结构、功能各向异性被广泛应用于组织工程、药物递送、癌症治疗、生物影像和传感等医学领域。目的:阐述Janus微/纳米颗粒在生物医学的前沿应用。方法:通过计算机检索中国知网、万方、PubMed、Web of Science数据库中2010-2024年发表的相关文献,分别以“Janus纳米颗粒,Janus颗粒,双面神颗粒,药物递送,癌症治疗,生物影像,生物传感,组织工程”和“Janus nanoparticle,Janus particle,Drug delivery,Cancer therapy,Biosensing,Bioimaging,Tissue engineering”为中、英文检索词,进行筛选、整理、归纳、总结,最终纳入69篇文献进行综述。结果与结论:Janus微/纳米颗粒可根据基础材料性质分为有机、无机、有机-无机复合三大类,其合成策略有遮蔽、自组装、相分离、微流控和成核生长等。Janus微/纳米颗粒可通过高负载率、门控释放、自主运动等特性进行高效率药物递送。Janus微/纳米颗粒除了增强传统癌症治疗措施(放化疗)的治疗效果外,还可以应用于细胞免疫、蛋白药物、细胞铁死亡等新兴癌症治疗方法;可应用于增强生物影像(CT、MRI、超声)的增敏剂,实现高质量成像,用于指导诊断和治疗;可通过运载生长因子、增强生物支架机械性能和抗菌效果,应用于组织工程。综合目前的研究,研究者们通过集合不同有机聚合物、无机材料的物化特性以不同的合成策略合成功能定制的Janus微/纳米颗粒,应用于复杂的生物医学领域。目前Janus微/纳米颗粒应用于组织再生领域、大规模生产和人体临床试验的报道较少,因此该类材料的开发、合成策略、临床安全评估和转化仍需投入更大的研究力度。展开更多
Herein,a simple and effective outer-surface interactions assisted supramolecular hierarchical assembly has been first exploited to uniformly distribute tungstosilicic acid(TSA)inside the porous structure of cucurbit[1...Herein,a simple and effective outer-surface interactions assisted supramolecular hierarchical assembly has been first exploited to uniformly distribute tungstosilicic acid(TSA)inside the porous structure of cucurbit[10]uril-based single-layer 2D supramolecular-organic-frameworks(Q[10]-SOFs)in water.Importantly,the 2D Q[10]-SOFs can further serve as light harvesting antenna,achieving fast energy transfer to the embedded redox-active TSA upon photoexcitation,resulting in efficient visible light-driven selective oxidation of benzyl alcohols into the corresponding aldehydes in high yield at room temperature.Further studies revealed that the integrated of 2D Q[10]-SOFs and TSA played a key role in the catalytic process,due to the presence of a novel stepwise electron transfer route in the single-layer hybrid 2D structures.展开更多
Several natural organism can change shape under external stimuli. These natural phenomena have inspired a vast amount of research on exploration and implementation of reconfigurable shape transformation. The Janus str...Several natural organism can change shape under external stimuli. These natural phenomena have inspired a vast amount of research on exploration and implementation of reconfigurable shape transformation. The Janus structure is a promising approach to achieve shape transformation based on its heterogeneous chemical or physical properties on opposite sides.However, the heterogeneity is generally realized by multi-step processing, different materials,and/or different processing parameters. Here, we present a simple and flexible method of producing p H-sensitive Janus microactuators from a single material, using the same laser printing parameters. These microactuators exhibit reversible structural deformations with large bending angles of ~31°and fast response(~0.2 s) by changing the p H value of the aqueous environment. Benefited from the high flexibility of the laser printing technique and the spatial arrangements, pillar heights, and bending directions of microactuators are readily controlled,enabling a variety of switchable ordered patterns and complex petal-like structures on flat surfaces and inside microchannels. Finally, we explore the potential applications of this method in information encryption/decryption and microtarget capturing.展开更多
基金supported by the National Natural Science Foundation of China(52074320)Petrochina Strategic Cooperation Science and Technology Project(ZLZX2020-01-04-03)。
文摘Janus amphiphilic polymer nanosheets(JAPNs)with anisotropic morphology and distinctive perfor-mance have aroused widespread interest.However,due to the difficulty in synthesis and poor dispersion stability,JAPNs have been scarcely reported in the field of enhancing oil recovery(EOR).Herein,a kind of organic-based flexible JAPNs was prepared by paraffin emulsion methods.The lateral sizes of JAPNs were ranging from hundreds of nanometers to several micrometers and the thickness was about 3 nm.The organic-based nanosheets were equipped with remarkably flexible structures,which could improve their injection performance.The dispersion and interfacial properties of JAPNs were studied systematically.By modification of crosslinking agent containing multiple amino groups,the JAPNs had excellent hydro-philicity and salt resistance compared with conventional inorganic or composite nanosheets.The settling time of nanosuspension with NaCl and CaCl_(2) at a low salinity of 1000 mg/L was over 240 h.The value could also remain 124 h under the salinity of 10,000 mg/L NaCl.With the dual functionalities of Janus amphiphilic nature and nanoparticles'Pickering effect,JAPNs could change rock wettability and form emulsions as"colloidal surfactants",In particular,a new technology called optical microrheology was pioneered to explore the destabilization state of nanosuspensions for the first time.Since precipitation lagged behind aggregation,especially for stable suspension systems,the onset of the unstable behavior was difficult to be detected by conventional methods,which should be the indicator of reduced effec-tiveness for nanofluid products.In addition,the oil displacement experiments demonstrated that the JAPNs could enhance oil recovery by 17.14%under an ultra-low concentration of 0.005%and were more suitable for low permeability cores.The findings can help for a better understanding of the material preparation of polymer nanosheets.We also hope that this study could shed more light on the nano-flooding technology for EOR.
基金supported by the National Natural Science Foundation of China(No.22271090)。
文摘Herein,a simple and effective outer-surface interactions assisted supramolecular hierarchical assembly has been first exploited to uniformly distribute tungstosilicic acid(TSA)inside the porous structure of cucurbit[10]uril-based single-layer 2D supramolecular-organic-frameworks(Q[10]-SOFs)in water.Importantly,the 2D Q[10]-SOFs can further serve as light harvesting antenna,achieving fast energy transfer to the embedded redox-active TSA upon photoexcitation,resulting in efficient visible light-driven selective oxidation of benzyl alcohols into the corresponding aldehydes in high yield at room temperature.Further studies revealed that the integrated of 2D Q[10]-SOFs and TSA played a key role in the catalytic process,due to the presence of a novel stepwise electron transfer route in the single-layer hybrid 2D structures.
基金the Hong Kong Scholar Program (XJ2018035) for their financial supportsupported by Research Grants Council of Hong Kong (No. JLFS/E-402/18)National Natural Science Foundation of China (No. 51805509)。
文摘Several natural organism can change shape under external stimuli. These natural phenomena have inspired a vast amount of research on exploration and implementation of reconfigurable shape transformation. The Janus structure is a promising approach to achieve shape transformation based on its heterogeneous chemical or physical properties on opposite sides.However, the heterogeneity is generally realized by multi-step processing, different materials,and/or different processing parameters. Here, we present a simple and flexible method of producing p H-sensitive Janus microactuators from a single material, using the same laser printing parameters. These microactuators exhibit reversible structural deformations with large bending angles of ~31°and fast response(~0.2 s) by changing the p H value of the aqueous environment. Benefited from the high flexibility of the laser printing technique and the spatial arrangements, pillar heights, and bending directions of microactuators are readily controlled,enabling a variety of switchable ordered patterns and complex petal-like structures on flat surfaces and inside microchannels. Finally, we explore the potential applications of this method in information encryption/decryption and microtarget capturing.
