scholarly journals Fabrication of Ring-Shaped Deposits of Polystyrene Microparticles Driven by Thermocapillary Mechanism

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5267
Author(s):  
Mohammed Al-Muzaiqer ◽  
Natalia Ivanova ◽  
Denis Klyuev
Keyword(s):  
Materials Science ◽  
Flow Direction ◽  
Advanced Materials ◽  
Heating And Cooling ◽  
Simultaneous Control ◽  
Field Emission Displays ◽  
Ring Structures ◽  
Source Sink ◽  
Evaporative Lithography ◽  
Polystyrene Microparticles

Fabrication of ring-shaped deposits of microparticles on solid surfaces with the desired length scales and morphology of particle arrangements is of great importance when developing modern optical and electronic resonators, chemical sensors, touch screens, field-emission displays, porous materials, and coatings with various functional properties. However, the controlled formation of ring-shaped patterns scaling from a few millimeters up to centimeters with simultaneous control of particle arrangement at the microscale is one of the most challenging problems in advanced materials science and technology. Here, we report a fabrication approach for ring-shaped structures of microparticles on a glass surface that relied on a local thermal impact produced by the subsurface heater and heat sink. Thermocapillary convection in the liquid covering microparticles in combination with evaporative lithography is responsible for the particle transport and the assembling into the ring-shaped patterns. An advantageous feature of this approach is based on the control of thermocapillary flow direction, achieved by changing the sign of the temperature gradient in the liquid, switching between heating and cooling modes. That allows for changing the particle transfer direction to create the ring-shaped deposits and dynamically tune their size and density distribution. We have studied the influence of the power applied to the heat source/sink and the duration of the applied thermal field on the rate of the ring fabrication, the sizes of the ring and the profile of the particle distribution in the ring. The proposed method is flexible to control simultaneously the centimeter scale and microscale processes of transfer and arrangements of particles and can be applied to the fabrication of ring structures of particles of different nature and shape.

scholarly journals Up Close: Center for Advanced Materials at Lawrence Berkeley Laboratory

MRS Bulletin ◽  
1986 ◽  
Vol 11 (4) ◽  
pp. 27-27 ◽  
Author(s):  
John J. Gilman
Keyword(s):  
Materials Science ◽  
Magnetic Moments ◽  
National Laboratory ◽  
National Policy ◽  
Chemical Properties ◽  
Educational Process ◽  
University Of California ◽  
Advanced Materials ◽  
Lawrence Berkeley Laboratory ◽  
The University

The boundaries between the present performance of materials and the requirements of device designers have for centuries been moving forward. The steps taken to draw these two together are sometimes large; more often they are small. As they occur, we find materials that are stronger, have larger magnetic moments, have higher electron mobilities, etc. Each time the property profile improves, understanding of the physical and chemical properties advances, and new engineering devices based on the improved profile are invented and developed.The purpose of the Center for Advanced Materials (CAM) at the Lawrence Berkeley Laboratory (LBL) is to enhance the inter-play between advances in the property profiles of materials and advances in the chemical and physical understanding of them. For this purpose, the location of CAM can be described as ideal. The proximity of this national laboratory to the campus of the University of California at Berkeley provides an unusually rich intellectual setting for the Center. It also provides unique opportunities for the University students and faculty who conduct materials-related research. Indeed, the arrangement should be a model for similar organizations, and it represents a solid method for strengthening materials science and technology throughout the nation.National policy in critical materials has given the national laboratories—including LBL—strong direction and incentive to collaborate with industry and the research universities. This incentive led to the establishment of CAM in order to build on the symbiosis between LBL and the University of California at Berkeley. It strives to extend this symbiosis by bringing industry into the ongoing educational process and by making its special facilities more readily available to industrial researchers.

scholarly journals Directed nucleation and growth by balancing local supersaturation and substrate/nucleus lattice mismatch

2018 ◽  
Vol 115 (14) ◽  
pp. 3575-3580 ◽  
Author(s):  
L. Li ◽  
A. J. Fijneman ◽  
J. A. Kaandorp ◽  
J. Aizenberg ◽  
W. L. Noorduin
Keyword(s):  
Self Assembly ◽  
Lattice Mismatch ◽  
Barium Carbonate ◽  
Growth Direction ◽  
Nucleation And Growth ◽  
Advanced Materials ◽  
Carbonate Concentration ◽  
Nucleation Barrier ◽  
Simultaneous Control ◽  
Local Supersaturation

Controlling nucleation and growth is crucial in biological and artificial mineralization and self-assembly processes. The nucleation barrier is determined by the chemistry of the interfaces at which crystallization occurs and local supersaturation. Although chemically tailored substrates and lattice mismatches are routinely used to modify energy landscape at the substrate/nucleus interface and thereby steer heterogeneous nucleation, strategies to combine this with control over local supersaturations have remained virtually unexplored. Here we demonstrate simultaneous control over both parameters to direct the positioning and growth direction of mineralizing compounds on preselected polymorphic substrates. We exploit the polymorphic nature of calcium carbonate (CaCO3) to locally manipulate the carbonate concentration and lattice mismatch between the nucleus and substrate, such that barium carbonate (BaCO3) and strontium carbonate (SrCO3) nucleate only on specific CaCO3 polymorphs. Based on this approach we position different materials and shapes on predetermined CaCO3 polymorphs in sequential steps, and guide the growth direction using locally created supersaturations. These results shed light on nature’s remarkable mineralization capabilities and outline fabrication strategies for advanced materials, such as ceramics, photonic structures, and semiconductors.

Five-Membered Hetarene N-Oxides: Recent Advances in Synthesis and Reactivity

Synthesis ◽  
2021 ◽  
Author(s):  
Leonid Fershtat ◽  
Fedor Teslenko
Keyword(s):  
Transition Metal ◽  
Medicinal Chemistry ◽  
Materials Science ◽  
State Of The Art ◽  
Short Review ◽  
Advanced Materials ◽  
Metal Free ◽  
Recent Advances ◽  
Application Potential ◽  
Metal Catalyzed

Five-membered heterocyclic N-oxides attracted special attention due to their strong application potential in medicinal chemistry and advanced materials science. In this regard, novel methods for their synthesis and functionalization are constantly required. In this short review, recent state-of-the-art achievements in the chemistry of isoxazoline N-oxides, 1,2,3-triazole 1-oxides and 1,2,5-oxadiazole 2-oxides are briefly summarized. Main routes to transition-metal-catalyzed and metal-free functionalization protocols along with mechanistic considerations are outlined. Transformation patterns of the hetarene N-oxide rings as precursors to other nitrogen heterocyclic systems are also presented.

Research progress in materials-oriented chemical engineering in China

2019 ◽  
Vol 35 (8) ◽  
pp. 917-927 ◽  
Author(s):  
Hao Jiang ◽  
Yongsheng Han ◽  
Qiang Zhang ◽  
Jiexin Wang ◽  
Yiqun Fan ◽  
...  
Keyword(s):  
Chemical Engineering ◽  
Materials Science ◽  
Industrial Applications ◽  
Advanced Materials ◽  
Research Progress ◽  
Material Research ◽  
Engineering Science ◽  
New Materials ◽  
Engineering Development ◽  
Recent Advances

Abstract Materials-oriented chemical engineering involves the intersection of materials science and chemical engineering. Development of materials-oriented chemical engineering not only contributes to material research and industrialization techniques but also opens new avenues for chemical engineering science. This review details the major achievements of materials-oriented chemical engineering fields in China, including preparation strategies for advanced materials based on the principles of chemical engineering as well as innovative separation and reaction techniques determined by new materials. Representative industrial applications are also illustrated, highlighting recent advances in the field of materials-oriented chemical engineering technologies. In addition, we also look at the ongoing trends in materials-oriented chemical engineering in China.

scholarly journals Unsteady Radiative Natural Convective MHD Nanofluid Flow Past a Porous Moving Vertical Plate with Heat Source/Sink

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 854 ◽  
Author(s):  
Talha Anwar ◽  
Poom Kumam ◽  
Zahir Shah ◽  
Wiboonsak Watthayu ◽  
Phatiphat Thounthong
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
Heat Sink ◽  
Vertical Plate ◽  
Flow Direction ◽  
Transverse Magnetic ◽  
Thermal Profile ◽  
Nanofluid Flow ◽  
Partial Differential ◽  
Source Sink

In this research article, we investigated a comprehensive analysis of time-dependent free convection electrically and thermally conducted water-based nanofluid flow containing Copper and Titanium oxide (Cu and TiO 2 ) past a moving porous vertical plate. A uniform transverse magnetic field is imposed perpendicular to the flow direction. Thermal radiation and heat sink terms are included in the energy equation. The governing equations of this flow consist of partial differential equations along with some initial and boundary conditions. The solution method of these flow interpreting equations comprised of two parts. Firstly, principal equations of flow are symmetrically transformed to a set of nonlinear coupled dimensionless partial differential equations using convenient dimensionless parameters. Secondly, the Laplace transformation technique is applied to those non-dimensional equations to get the close form exact solutions. The control of momentum and heat profile with respect to different associated parameters is analyzed thoroughly with the help of graphs. Fluid accelerates with increasing Grashof number (Gr) and porosity parameter (K), while increasing values of heat sink parameter (Q) and Prandtl number (Pr) drop the thermal profile. Moreover, velocity and thermal profile comparison for Cu and TiO 2 -based nanofluids is graphed.

Shape Memory Alloy Based Rotational Actuator

2018 ◽  
Author(s):  
Nick Hofmann ◽  
Michael P. Hennessey
Keyword(s):  
Shape Memory ◽  
Rotational Motion ◽  
Thermal Analyses ◽  
Peak Torque ◽  
Advanced Materials ◽  
Constant Torque ◽  
Heating And Cooling ◽  
Air Convection ◽  
Technological Developments ◽  
Forced Air

Due to recent technological developments in advanced materials, the integration of shape memory alloys (SMAs) into new machines and mechanisms is becoming more common and it offers tremendous potential for the future. Using currently available properties of common SMA materials, the paper’s contribution is to: Study through dynamic simulation the potential offered by SMA springs to serve as the basis for rotary actuation. In the process, the SMA displaces a rocker arm rotating about an axis to induce rotational motion of a driveshaft, in effect converting a force into rotational motion. When embedded in a cycle with heating & cooling phases and a resetting mechanism, unidirectional rotational motion can be achieved. Regarding heating and cooling cycles, forced air convection is used to reduce thermal cycle cooling and is calculated via transient thermal analyses. Using typical parameter values for the representative design considered, through forced air convection, cooling cycles are reduced from approximately 30 seconds (natural) to 5.5 seconds (forced) and as a result, a complete system cycle can occur in 10 seconds, with the applied inertial load of 2.0 kg-m2. Using MATLAB and Simulink, a nonlinear 3rd order dynamic system model was created and simulations were performed. One complicating factor concerned angular limits and the necessary thermal cycling, which was solved through appropriate sequencing and resetting of integrators for different phases. Simulation results for the design considered show that a peak torque of 1.72 N-m is possible and that relatively smooth motion and approximately constant torque output is also possible through the addition of a few more rocker arm systems, properly commutated. Lastly, the design analysis framework and results may inspire future realization of actual devices.

scholarly journals LA SCIENZA DEI MATERIALI

2015 ◽  
Author(s):  
Antonio Papagni
Keyword(s):  
Environmental Impact ◽  
Everyday Life ◽  
Materials Science ◽  
Advanced Materials ◽  
Fundamental Aspect ◽  
Organic Polymers ◽  
Scientific Disciplines ◽  
Application Potential ◽  
Low Costs

Materials Science represents the natural convergence of hard scientific disciplines such as Physics Mathematics and Chemistry whom synergic contribution to its definition and evolution is at the basis of huge technologic development observed during the last few decades. The wide variety of materials under investigation by this discipline is both strategic for the economy of a Nation as well as a fundamental aspect of everyday life. Among the most relevant ones so far proposed, many advanced materials are organic-based or, in other words, constituted by molecules or organic polymers, not only for their application potential, low costs and preparation flexibility but also for their processability and limited environmental impact.

Up Close: Northwestern University Materials Research Center

MRS Bulletin ◽  
1986 ◽  
Vol 11 (5) ◽  
pp. 36-36
Author(s):  
Stephen H. Carr
Keyword(s):  
Federal Government ◽  
National Science Foundation ◽  
Chemical Engineering ◽  
Materials Science ◽  
Advanced Materials ◽  
Research Center ◽  
Northwestern University ◽  
National Science ◽  
Materials Research ◽  
Materials Science And Engineering

The Materials Research Center at Northwestern University is an interdisciplinary center that supports theoretical and applied research on experimental advanced materials. Conceived during the post-Sputnik era, it is now in its 26th year.The Center, housed in the university's Technological Institute, was one of the first three centers funded at selected universities by the federal government in 1960. The federal government, through the National Science Foundation, now supplies $2.4 million annually toward the Center's budget, and Northwestern University supplements this amount. Approximately one third of the money is used for a central pool of essential equipment, and the other two thirds is granted to professors for direct support of their research. Large amounts of time on supercomputers are also awarded to the Materials Research Center from the National Science Foundation and other sources.The Center's role enables it to provide partial support for Northwestern University faculty working at the frontiers of materials research and to purchase expensive, sophisticated equipment. All members of the Center are Northwestern University investigators in the departments of materials science and engineering, chemical engineering, electrical engineering, chemistry, or physics. The Materials Research Center is a major agent in fostering cross-departmental research efforts, thereby assuring that materials research at Northwestern University includes carefully chosen groups of faculty in physics, chemistry, and various engineering departments.

The Changing Paradigm for Business Success in Advanced Materials and Components Manufacturing

MRS Bulletin ◽  
1992 ◽  
Vol 17 (4) ◽  
pp. 35-37 ◽  
Author(s):  
B. Barnett ◽  
H.K. Bowen ◽  
K. Clark
Keyword(s):  
Materials Science ◽  
Electronic Materials ◽  
Dielectric Materials ◽  
Time Frame ◽  
Molecular Engineering ◽  
Advanced Materials ◽  
Business Success ◽  
Massachusetts Institute Of Technology ◽  
Science And Engineering ◽  
Institute Of Technology

The use of manmade materials progressed rather slowly until the science and technology of metals, refractories, and glass burst forth in the mid-1800s and continued its infancy through the first decades of the 20th century. In fact, much of the scientific wherewithal in industrial nations focused on the development of manmade materials from the standpoint of properties and fabrication processes. From the discipline of metal physics, which emerged in the 1930s, and from the scientific activities in ceramics, polymers, and electronic materials that blossomed in the 1940s and 1950s, a science and engineering base was established, enabling advanced materials and components to be fabricated, often for specific end-user applications. The molecular engineering of crystals, for example, has its roots in von Hippel's studies of dielectric materials at the Massachusetts Institute of Technology, which began in the 1930s. In this time frame, society, which had primarily used such materials as wood, gypsum, clay, copper, zinc, lead, and iron, turned to a broader set of materials to meet new uses. These new applications required an understanding not only of the composition of matter, but of novel and difficult processes as well. Research specialties broadened.From the late 1950s to the present, the knowledge base for materials and components has exploded. In this period, the scientific and technological field of endeavor—materials science and engineering (MS&E) — evolved from a collection of discrete, disparate arts and crafts with varied amounts of science and practitioners who generally did not stray from their own specialties to a more diffuse field where researchers take a broader approach to materials research and practice.

Advanced Processing of Composites

MRS Bulletin ◽  
1988 ◽  
Vol 13 (4) ◽  
pp. 21-27 ◽  
Author(s):  
B. Tittmann
Keyword(s):  
Materials Science ◽  
Space Station ◽  
Advanced Materials ◽  
Flow Modeling ◽  
Science And Engineering ◽  
Aerospace Vehicles ◽  
Materials Science And Engineering ◽  
Future Work ◽  
Aerospace Plane ◽  
Processing Of Composites

The preservation of U.S. aeronautical leadership is an economic and military necessity, but it is by no means assured. The rise of Airbus, Ariane, and Embraer has been lightning fast; tomorrow could see the development of Japan's FSC or Israel's Lavi. Our competitors are well organized and often enjoy the support of their governments. Our capabilities are no longer unique; thus our future work is clearly defined for us.The key to continued U.S. preeminence in aerospace is to be found in the further research, development, and application of a group of revolutionary technologies in the areas of propulsion, numerical and symbolic computation, laminar flow modeling, and advanced materials and structures. Exploitation of the emerging technologies in these areas by industry, government, and universities will significantly impact the performance and cost of future aerospace vehicles and systems. Materials science and engineering, particularly the discipline of nondestructive evaluation, will play a major role in making such continued aerospace leadership a reality.From the use of plastic and glass radomes in the first jet engine demonstrators to the composite parts of today's most advanced aircraft, the need to ensure reliable materials has always been critical. Advanced materials and structural concepts offer the opportunity for significant airframe improvements on all types of aircraft. Indeed tomorrow's aerospace structures, such as the National Aerospace Plane, the Space Station, as well as the ATF and SDI-related items will employ a myriad of exotic materials that must be extremely reliable and highly producible.

Sign in / Sign up

Export Citation Format

Share Document