scholarly journals Linear assembly of patchy and non-patchy nanoparticles

2016 ◽  
Vol 191 ◽  
pp. 189-204 ◽  
Author(s):  
Rachelle M. Choueiri ◽  
Elizabeth Galati ◽  
Anna Klinkova ◽  
Héloïse Thérien-Aubin ◽  
Eugenia Kumacheva

Linear assemblies of nanoparticles show promising applications due to their collective electronic, optical and magnetic properties. Rational design and controllable organization of nanoparticles in one-dimensional structures can strongly benefit from the marked similarity between conventional step-growth polymerization reactions and directional step-wise assembly of nanoparticles in linear chains. Here we show different aspects of the “polymerization” approach to the solution-based self-assembly of polymer-functionalized metal nanoparticles with different chemical compositions, shapes and dimensions. The self-assembly was triggered by inducing solvophobic attraction between polymer ligands, due to the change in solvent quality. We show that both anisotropic (patchy) nanoparticles and nanoparticles uniformly capped with polymer molecules can self-assemble in linear chains. We explore the control of chain length, morphology, and composition, discuss the ability to form isotropic and hierarchical structures and show the properties and potential applications of linear assemblies of plasmonic nanoparticles.


2018 ◽  
Vol 6 (42) ◽  
pp. 11384-11391 ◽  
Author(s):  
Xiaodan Hong ◽  
Qun Liu ◽  
Xiaoyue Gao ◽  
Chunfeng He ◽  
Xingyan You ◽  
...  

Coralloid Co9S8–CuS hierarchical structures with high stability and remarkable electrochemical activity in QDSCs are firstly in situ grown on FTO substrates, which are also applicative on other flexible conductive substrates for potential applications in wearable devices.



Author(s):  
Alex Inayeh ◽  
Ryan Groome ◽  
Ishwar Singh ◽  
Alex Veinot ◽  
Felipe Iima ◽  
...  

The production of ordered arrays of organic molecules on metallic surfaces by means of self-assembly is one of the most powerful methods for controlled patterning on the nanometer scale. Although the self-assembly of sulfurbased ligands has been studied for decades, the thermal and oxidative instability of these systems introduces challenges in many potential applications. In recent years, it has been shown that a new ligand class, N-heterocyclic carbenes (NHCs), bind to metal surfaces via a metal–carbon covalent bond, resulting in monolayers with much greater stability. However, fundamental questions surrounding self-assembly in this new ligand class remain unanswered, including the simple questions of what controls NHC orientation on the surface and under what conditions they self-assemble. Herein we describe how NHC structure, surface density, deposition temperature, and annealing temperature control mobility, thermal stability, NHC surface geometry, self-assembly, and the exact chemical nature of the surface structures. These data provide the first general set of guidelines to enable the rational design of highly ordered NHC-based monolayers. Considering that NHCs may supplant thiols as the functionalization agent of choice in a wide range of applications, a detailed understanding of their surface chemistry is crucial for the success of these next-generation monolayers.



Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1350 ◽  
Author(s):  
Jian Li ◽  
Fuping Dong ◽  
Liangyu Lu ◽  
Hongwei Li ◽  
Yuzhu Xiong ◽  
...  

Raspberry-like hollow-spheres-on-sphere (HSOS) particles with reactive surfaces, uniform sizes and monodisperse properties were rational designed and fabricated to immobilize gold nanoparticles for the catalytic reduction of 4-nitrophenol. HSOS polysilsesquioxane (PSQ) particles were constructed by an organic alkali catalyzed sol-gel process from trialkoxysilane precursors with stabilized polystyrene (PS) nanoparticles as both a sacrifice template and a Pickering emulsifier. The PSQ particles were fabricated in an ice bath with methyltrimethoxysilane and mercaptopropyltrimethoxysiane as a co-precursor, tetramethylammonium hydroxide (TMAH) as a catalyst, polyvinylpyrrolidone (PVP) and sodium lignosulfonat as co-stabilizers and PS latex as a hard template. The formation mechanism of the hierarchical particles was investigated in detail by the time study through imaging the particles at regular time intervals during the reaction process. Various effect factors on the morphology were studied systematically which showed that the precursor composition, the content of PS, TMAH and PVP are the most important factors. The hierarchical structure combined with the mercaptopropyl groups on both the surface and the skeleton to make it possible to adsorb guest molecules. Au nanoparticles were immobilized on the particles for the catalytic reduction of 4-nitrophenol to 4-aminophenol. The unique PSQ colloids with hollow-spheres-on-sphere extended the family of the hierarchical structures and has shown the potential applications in separations, drug delivery and heterogeneous catalysts.



2020 ◽  
Author(s):  
Alex Inayeh ◽  
Ryan Groome ◽  
Ishwar Singh ◽  
Alex Veinot ◽  
Felipe Iima ◽  
...  

The production of ordered arrays of organic molecules on metallic surfaces by means of self-assembly is one of the most powerful methods for controlled patterning on the nanometer scale. Although the self-assembly of sulfurbased ligands has been studied for decades, the thermal and oxidative instability of these systems introduces challenges in many potential applications. In recent years, it has been shown that a new ligand class, N-heterocyclic carbenes (NHCs), bind to metal surfaces via a metal–carbon covalent bond, resulting in monolayers with much greater stability. However, fundamental questions surrounding self-assembly in this new ligand class remain unanswered, including the simple questions of what controls NHC orientation on the surface and under what conditions they self-assemble. Herein we describe how NHC structure, surface density, deposition temperature, and annealing temperature control mobility, thermal stability, NHC surface geometry, self-assembly, and the exact chemical nature of the surface structures. These data provide the first general set of guidelines to enable the rational design of highly ordered NHC-based monolayers. Considering that NHCs may supplant thiols as the functionalization agent of choice in a wide range of applications, a detailed understanding of their surface chemistry is crucial for the success of these next-generation monolayers.



Author(s):  
M. Sarikaya ◽  
J. T. Staley ◽  
I. A. Aksay

Biomimetics is an area of research in which the analysis of structures and functions of natural materials provide a source of inspiration for design and processing concepts for novel synthetic materials. Through biomimetics, it may be possible to establish structural control on a continuous length scale, resulting in superior structures able to withstand the requirements placed upon advanced materials. It is well recognized that biological systems efficiently produce complex and hierarchical structures on the molecular, micrometer, and macro scales with unique properties, and with greater structural control than is possible with synthetic materials. The dynamism of these systems allows the collection and transport of constituents; the nucleation, configuration, and growth of new structures by self-assembly; and the repair and replacement of old and damaged components. These materials include all-organic components such as spider webs and insect cuticles (Fig. 1); inorganic-organic composites, such as seashells (Fig. 2) and bones; all-ceramic composites, such as sea urchin teeth, spines, and other skeletal units (Fig. 3); and inorganic ultrafine magnetic and semiconducting particles produced by bacteria and algae, respectively (Fig. 4).



2019 ◽  
Vol 10 (45) ◽  
pp. 6116-6121 ◽  
Author(s):  
Tan Ji ◽  
Lei Xia ◽  
Wei Zheng ◽  
Guang-Qiang Yin ◽  
Tao Yue ◽  
...  

We present a new family of porphyrin-functionalized coordination star polymers prepared through combination of coordination-driven self-assembly and post-assembly polymerization. Their self-assembly behaviour in water and potential for photodynamic therapy were demonstrated.



2020 ◽  
Author(s):  
Yunzhong Wang ◽  
Saixing Tang ◽  
Yating Wen ◽  
Shuyuan Zheng ◽  
Bing Yang ◽  
...  

<div>Persistent room-temperature phosphorescence (p-RTP) from pure organics is attractive </div><div>due to its fundamental importance and potential applications in molecular imaging, </div><div>sensing, encryption, anticounterfeiting, etc.1-4 Recently, efforts have been also made in </div><div>obtaining color-tunable p-RTP in aromatic phosphors5 and nonconjugated polymers6,7. </div><div>The origin of color-tunable p-RTP and the rational design of such luminogens, </div><div>particularly those with explicit structure and molecular packing, remain challenging. </div><div>Noteworthily, nonconventional luminophores without significant conjugations generally </div><div>possess excitation-dependent photoluminescence (PL) because of the coexistence of </div><div>diverse clustered chromophores6,8, which strongly implicates the possibility to achieve </div><div>color-tunable p-RTP from their molecular crystals assisted by effective intermolecular </div><div>interactions. Here, inspirited by the highly stable double-helix structure and multiple </div><div>hydrogen bonds in DNA, we reported a series of nonconventional luminophores based on </div><div>hydantoin (HA), which demonstrate excitation-dependent PL and color-tunable p-RTP </div><div>from sky-blue to yellowish-green, accompanying unprecedentedly high PL and p-RTP </div><div>efficiencies of up to 87.5% and 21.8%, respectively. Meanwhile, the p-RTP emissions are </div><div>resistant to vigorous mechanical grinding, with lifetimes of up to 1.74 s. Such robust, </div><div>color-tunable and highly efficient p-RTP render the luminophores promising for varying </div><div>applications. These findings provide mechanism insights into the origin of color-tunable </div><div>p-RTP, and surely advance the exploitation of efficient nonconventional luminophores.</div>



2019 ◽  
Vol 24 (32) ◽  
pp. 3739-3757 ◽  
Author(s):  
Chandrabose Selvaraj ◽  
Sanjeev K. Singh

Nucleic acid is the key unit and a predominant genetic material for interpreting the fundamental basis of genetic information in an organism and now it is used for the evolution of a novel group of therapeutics. To identify the potential impact on the biological science, it receives high recognition in therapeutic applications. Due to its selective recognition of molecular targets and pathways, DNA significantly imparts tremendous specificity of action. Examining the properties of DNA holds numerous advantages in assembly, interconnects, computational elements, along with potential applications of DNA self-assembly and scaffolding include nanoelectronics, biosensors, and programmable/autonomous molecular machines. The interaction of low molecular weight, small molecules with DNA is a significant feature in pharmacology. Based on the mode of binding mechanisms, small molecules are categorized as intercalators and groove binders having a significant role in target-based drug development. The understanding mechanism of drug-DNA interaction plays an important role in the development of novel drug molecules with more effective and lesser side effects. This article attempts to outline those interactions of drug-DNA with both experimental and computational advances, including ultraviolet (UV) -visible spectroscopy, fluorescent spectroscopy, circular dichroism, nuclear magnetic resonance (NMR), molecular docking and dynamics, and quantum mechanical applications.



2020 ◽  
Vol 16 ◽  
Author(s):  
Muhammad Bilal Tahir ◽  
Aleena Shoukat ◽  
Tahir Iqbal ◽  
Asma Ayub ◽  
Saff-e Awal ◽  
...  

: The field of nanosensors has been gaining a lot of attention due to its properties such as mechanical and electrical ever since its first discovery by Dr. Wolter and first mechanical sensor in 1994. The rapidly growing demand of nanosensors has become profitable for a multidisciplinary approach in designing and fabrication of materials and strategies for potential applications. Frequent stimulating advancements are being suggested and established in recent years and thus heading towards multiple applications including food safety, healthcare, environmental monitoring, and biomedical research. Nanofabrication being an efficient method has been used in different industries like medical pharmaceutical for their complex functional geometry at a lower scale. These nanofabrications apply through different methods. There are five most commonly known methods which are frequently used, including top-down lithography, molecular self-assembly, bottom-up assembly, heat and pull method for fabrication of biosensors, etching for fabrication of nanosensors etc. Nanofabrication help at the nanoscale to design and work with small models. But these models due to their small size and being sensitive need more care for use as well as more training and experience to do work with. All methods used for nanofabrication are good and helpful. But more preferred is molecular self-assembly as it is helpful in mass production. Nanofabrication has become an emerging and developing field and it assumed that in near future our world is known by the new devices of nanofabrication.



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