Two-Dimensional and Magic Size Layers of Metal Thiolates: Synthesis and Nanocalorimetry Characterization

金属硫醇盐的二维和神奇尺寸层：合成和纳米量热表征

• 批准号: 1006385
• 负责人: Leslie Allen
• 金额: $ 33.1万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1006385&HistoricalAwards=false
• 关键词: Two; Dimensional; Magic; Size; Layers

TECHNICAL SUMMARY: The PI proposes to synthesize and characterize extremely thin layers of Ag thiolate (AgSR) with the support from the Solid State and Materials Chemistry program in the Division of Materials Research. Crystals form in a variety of shapes and sizes but some crystals are more special than others. These special sizes, often referred to as Magic Number Sizes, are of great interest in materials chemistry and physics because often they are evidence of unique underlying properties of the material. AgSR is an interesting polymer in that it grows as stacked flat bilayers. The PI envisions lamellar AgSR to be a new model building block for bottom-up self assembly of superstructures that can be used in a variety of new material applications in physics, chemistry, biology and microelectronic technologies. The PI recently developed a new synthesis method using nanoparticles of metal which generates large AgSR crystal platelets. These crystals have diameters of 1 micron and heights of up to ~30 layers thick with nearly atomically flat surfaces (Langmuir 2009). One major objective in this proposal is to exploit the unusual planar attributes of AgSR and to extend this new synthesis path to produce crystals of the fundamental minimum thickness, one-layer two-dimensional AgSR crystals. This one-layer crystal is the ultimate starting point for bottom-up self-assembly synthesis. Discovery in 2004 of graphene has defied the conventional wisdom that these thin crystals could not exist because of an inherent instability in part due to reduced melting temperature (size-dependent melting). A major objective of this proposal is to measure the melting of these 1-layer crystals which to date has never been done. This goal will be accomplished using Nanocalorimetry. These structures can be used to study thermodynamics and size-dependent melting phenomenon with single-layer control of crystal size which has been implausible except for cluster beams. The PI proposes to study size-effects in this system using NanoDSC in addition to the formation of liquid crystal and metastable phases.NON-TECHNICAL SUMMARY: The scientific impact of this work will be in the development of generating new synthesis methods for applications in the microelectronics industry. Furthermore the new characterization techniques developed in thermal analysis will greatly expand our scientific ability to probe material properties at a very small size scale which is useful for advancement in Nanotechnology. The broad impact of this research will include the education and training of graduate students in the field of nanotechnology and the development of new synthesis methods. The students will be educated and trained in fabrication of MEMs devices using microelectronic techniques and in using self-assembly synthesis methods. Almost all of the students who have been trained by the PI are currently working in the microelectronics industry. In addition to formal journal articles, the dissemination of this work will be in the form of conference talks given by both the PI and graduate and undergraduate students along with Nanocalorimetry short courses in specialized Thermal Analysis conferences. By further developing the capabilities of the synthesis methods and NanoDSC technique, this work will add to the fabrication and instrumentation infrastructure of the country for basic science as well as for technology. Scientific collaborations are expected to be developed in the area of Thermal Analysis with groups in Spain and Canada as well as other research groups in the United States.

技术摘要：PI提议在材料研究部中的固态和材料化学计划的支持下合成和表征极度薄的Ag硫酸酯（AGSR）。 晶体形成多种形状和大小，但有些晶体比其他晶体更为特殊。这些特殊尺寸通常称为魔术数量，对材料化学和物理学具有很大的兴趣，因为它们通常是材料的独特基本特性的证据。 AGSR是一种有趣的聚合物，因为它会随着堆叠的平整双层型而生长。 PI设想Lamellar AGSR是一个新的模型构建块，用于自下而上的上层建筑，可用于物理，化学，生物学和微电子技术的各种新材料应用中。 PI最近使用金属的纳米颗粒开发了一种新的合成方法，该方法产生了大型AGSR晶体血小板。 这些晶体的直径为1微米，高度的高度厚度约为30层，厚度为几乎原子平坦的表面（Langmuir 2009）。该提案的一个主要目的是利用AGSR的异常平面属性，并扩展这种新的合成路径，以产生基本最小厚度的晶体，一层一层二维AGSR晶体。 这种单层晶体是自下而上自组合合成的最终起点。 在2004年的发现，石墨烯违反了传统的智慧，即由于温度降低（依赖尺寸依赖性熔化），部分原因是固有的不稳定性不存在。 该提案的一个主要目的是衡量迄今为止从未做过的1层晶体的熔化。 该目标将使用纳米级别法实现。 这些结构可用于研究热力学和尺寸依赖性的熔融现象，并具有对晶体大小的单层控制，除了簇束外，这是难以置信的。 PI建议除了形成液晶和可稳态阶段外，还使用Nanodsc研究了该系统中的尺寸效应。Non-technical摘要：这项工作的科学影响将是开发为微电源行业中应用新的合成方法的开发。此外，在热分析中开发的新特征技术将大大扩展我们以很小的尺寸探测材料特性的科学能力，这对于纳米技术的发展很有用。 这项研究的广泛影响将包括纳米技术领域的研究生的教育和培训以及新合成方法的发展。将使用微电子技术和使用自组装合成方法对学生进行教育和培训，从而在制造MEMS设备方面进行教育和培训。目前，几乎所有接受过PI培训的学生都在微电子行业工作。 除了正式的期刊文章外，这项工作的传播还将以PI和研究生和本科生进行的会议演讲形式以及专业热力分析会议的纳米层压简短课程。 通过进一步开发合成方法和Nanodsc技术的功能，这项工作将增加基础科学和技术国家的制造和仪器基础设施。 预计科学合作将在与西班牙和加拿大以及美国其他研究小组的热力分析领域开发。