PECASE: Response of Novel Suspensions of Magnetic Nanoparticles to Time Varying Magnetic Fields

新型磁性纳米颗粒悬浮液对时变磁场的响应。卡洛斯里纳尔迪，助理教授化学工程系，波多黎各大学，Mayaguez该职业发展计划结合了PI在牛顿流体中磁性纳米颗粒悬浮液建模和磁流变学表征方面的专业知识磁性纳米粒子在非牛顿流体和液晶中的悬浮液以及非牛顿流体的悬浮液等新型磁活性复合流体的合成和制备，牛顿流体中的球形纳米粒子。这些新的磁性流体随时间变化的磁场的响应将通过建模和experimentsusing交流磁阻计，磁双折射，磁流变仪与超声多普勒测速方法耦合的组合进行研究。该计划的教育和外联部分旨在通过以下方式增加西班牙裔等代表性不足的群体的参与并加强其教育：（1）在波多黎各服务水平低下的大学预科学校进行科学示范，并在夏季在实验室接待大学预科教师，（2）关于研究道德和手稿的研讨会以及旨在建立UPRM研究文化的提案准备，（3）《化工研究概论》课程的开发。 之前NSF在教育和推广方面的投资将通过与UPRM科学onWheels教育中心（SONWEC）和UW麦迪逊MRSEC跨学科研究小组（IEG）合作来利用，将针对大学前受众的教育模块翻译成西班牙语，用于波多黎各和美国拉丁裔社区。将开发新型磁活性复合流体，并从实验和理论上表征其对时变磁场的响应。悬浮的磁性纳米粒子是最近的兴趣，在纳米生物传感器来自流体动力学尺寸依赖的磁弛豫时间，并在磁流体热疗治疗癌症。在这些应用中，颗粒通常嵌入在非牛顿流体基质中，并且对振荡或旋转磁场的响应是关键问题。这项研究对胶体流体力学、流变学和纳米技术具有重要意义，将有助于开发磁性纳米粒子在传感器和癌症治疗中的应用。更广泛的影响：通过在UPRM开展拟议的研究，将显著提高来自代表性不足群体的学生的参与和教育。UPRM的化学工程系为650多名西班牙裔本科生提供服务，其中70%是女性。还有27名博士生，其中一半是西班牙裔美国公民。拟议的研讨会和课程介绍化学工程研究将整合和正规化的研究活动，在本科生和研究生的教育，同时发展研究文化，学生将学习的价值观，传统和作为一个研究人员的责任。拟议的推广和教育任务将通过SONWEC和IEG影响数千名西班牙裔大学预科生。将编制以研究为基础的教育材料，供波多黎各和美国的西班牙语社区使用。PI还将在夏季为大学预科教师提供有意义的研究经验。

ABSTRACTCAREER: Response of Novel Magnetic Nanoparticle Suspensions to Time Varying Magnetic FieldsDr. Carlos Rinaldi, Assistant ProfessorDepartment of Chemical Engineering, University of Puerto Rico, MayaguezThis career development plan combines the PIs expertise in modeling and magnetorheologicalcharacterization of suspensions of magnetic nanoparticles in Newtonian fluids (ferrofluids) withsynthesis and preparation of novel magnetically active complex fluids such as suspensions ofspherical magnetic nanoparticles in non-Newtonian fluids and liquid crystals and suspensions ofnon-spherical nanoparticles in Newtonian fluids. The response of these novel magnetic fluids totime varying magnetic fields will be studied through a combination of modeling and experimentsusing AC susceptometers, magnetic birefringence, and magnetorheometers coupled with theUltrasonic Doppler Velocimetry method. The education and outreach components of the plan aim to increase the participation and enhance the education of underrepresented groups such as Hispanics through: (1) science demonstrations at underserved pre-college schools in Puerto Rico and hosting of pre-college teachers in the laboratory during the summers, (2) seminars on research ethics and manuscript and proposal preparation aimed at establishing a Research Culture at UPRM, and (3) development of the course Introduction to Chemical Engineering Research. Prior NSF investments in education and outreach will be leveraged by partnering with the UPRM Science onWheels Educational Center (SONWEC) and the UW Madison MRSEC Interdisciplinary Research Group (IEG) to translate educational modules for pre-college audiences into Spanish, to be used in Puerto Rico and with US Latino communities.Intellectual Merit: Novel magnetically-active complex fluids will be developed and their response to time varying magnetic fields will be characterized experimentally and theoretically. Suspensions of magnetic nanoparticles are of recent interest in nanobiosensors derived from the hydrodynamic size dependence of the magnetic relaxation time, and in magnetic fluid hyperthermia treatment of cancer. In these applications the particles are typically embedded in a non-Newtonian fluid matrix and the response to oscillating or rotating magnetic fields is of key concern. The proposed research is of fundamental interest in colloidal hydrodynamics, rheology, nanotechnology, and will help develop applications of magnetic nanoparticles in sensors and cancer treatment.Broader Impact: By carrying out the proposed research at the UPRM, the participation and education of students from underrepresented groups will be significantly enhanced. The ChemicalEngineering Department at UPRM serves over 650 Hispanic undergraduate students, 70% of which are female. There are also 27 PhD students, half of which are Hispanic US citizens. The proposed seminars and the course Introduction to Chemical Engineering Research will integrate and formalize research activities in the education of undergraduate and graduate students while developing a Research Culture in which students will learn the values, traditions, and responsibilities of being a researcher. The proposed outreach and education tasks will impact thousands of Hispanic pre-college students through the SONWEC and IEG. Research-based educational materials will be developed for use in teaching Spanish-speaking communities in Puerto Rico and the US. The PI will also provide meaningful research experiences for pre-college teachers during the summer.