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

摘要：新型磁性纳米颗粒悬浮液对时变磁场的响应。波多黎各大学化学工程系助理教授Carlos Rinaldi这项职业发展计划结合了PI在牛顿流体(磁流体)中磁性纳米颗粒悬浮液的建模和磁流变学表征方面的专业知识，以及新型磁性活性复杂流体的合成和制备，例如球形磁性纳米颗粒在非牛顿流体和液晶中的悬浮，以及非球形纳米颗粒在牛顿流体中的悬浮。这些新型磁性液体对时变磁场的响应将通过使用交流磁感计、磁双折射和磁流变计与超声多普勒测速方法相结合的建模和实验相结合的方法来研究。该计划的教育和宣传部分旨在通过以下方式增加参与和加强拉美裔等人数不足的群体的教育：(1)在波多黎各服务不足的大学前学校进行科学演示，并在夏季在实验室接待大学前教师，(2)关于研究伦理和手稿的研讨会，以及旨在在UPRM建立研究文化的提案准备，以及(3)开发化学工程研究入门课程。NSF之前在教育和推广方面的投资将通过与UPRM科学轮子教育中心(SONWEC)和UW Madison MRSEC跨学科研究小组(IEG)合作来利用，将面向大学前观众的教育模块翻译成西班牙语，供波多黎各和美国拉丁裔社区使用。智力优势：将开发新型磁性复合流体，并将从实验和理论上表征其对时变磁场的响应。磁性纳米颗粒悬浮液在纳米生物传感器、磁弛豫时间的流体力学尺寸依赖关系以及磁流体热疗治疗癌症方面最近引起了人们的兴趣。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。拟议的研究对胶体流体动力学、流变学、纳米技术具有基本的兴趣，并将有助于开发磁性纳米颗粒在传感器和癌症治疗中的应用。广泛影响：通过在UPRM开展拟议的研究，来自代表性不足群体的学生的参与和教育将得到显著提高。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，其中一半是拉美裔美国公民。拟议的研讨会和化学工程研究导论课程将整合和规范本科生和研究生教育中的研究活动，同时发展一种研究文化，在这种文化中，学生将学习作为一名研究人员的价值观、传统和责任。拟议的外展和教育任务将通过SONWEC和IEG影响数千名西班牙裔大学前学生。将开发基于研究的教育材料，用于波多黎各和美国的西班牙语社区教学。暑假期间，PI还将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.