Design Synthesis And Self Assembly Of Giant Molecules Including Giant Surfactants And Giant Tetrahedrons Based On Poss Nanoparticles

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Design, Synthesis and Self-assembly of Giant Molecules, Including Giant Surfactants and Giant Tetrahedrons Based on POSS Nanoparticles

Author : Wenpeng Shan
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (139 download)

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Book Synopsis Design, Synthesis and Self-assembly of Giant Molecules, Including Giant Surfactants and Giant Tetrahedrons Based on POSS Nanoparticles by : Wenpeng Shan

Download or read book Design, Synthesis and Self-assembly of Giant Molecules, Including Giant Surfactants and Giant Tetrahedrons Based on POSS Nanoparticles written by Wenpeng Shan and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The self-assemble behavior of various giant surfactants with different functionalities and molecular architectures, which consist of compact and rigid molecular nanoparticles (MNPs) as head and flexible polymer chains as tail, is systematically studied. The benefit of utilizing MNPs comparing with AB type di-block copolymer which has become the model for probing microphase separation in bulk state is that the MNPs could be versatile functionalized at will to fabricate functional materials via collective secondary interactions. Herein, we investigated the effect of rigid-rod junction between two blocks of giant surfactants in bulk state using small angle X-ray scattering and transmission electron microscopy. Besides the segmental interaction (x, Flory-Huggins parameter) and volume fraction of one component (f), the interfacial energy takes a vital role in the process of self-assembly. By way of about 1 nm rigid-rod junction inserted into the giant surfactant system, the pathways of order-order phase transition (OOT) could be varied due to different molecular weight of polystyrene attached inducing diverse levels of gibbs free energy with temperature increasing, one proceeds from lamellar structure (LAM) directly to the hexagonally packed cylinder structure (CYL), one passes by the double gyroid structure (DG), another one travels from LAM to hexagonally perforated layer structure (HPL), then DG, finally reaches to the stable state, CYL that possesses the most curved interfacial area in these previous mentioned structures. And the model which describes these sorts of phase behaviors with interfacial tension and packing frustration competing each other could be verified via the phenomena that curved lamellar defects observed both in bright field TEM image and small angle x-ray scattering data, which could be occurred due to the relaxation of polymer chains promoting the increase of interfacial area without loosening the imbalance of chain crowding because of tightly packed MNPs to stimulate the OOT. This prototype of phase transition supporting a fully described phase diagram provides clues to control polymer self-assembly and fine-tune the morphology and phase behaviors at the nanometer scales. In the second topic, the giant tetrahedron was fabricated on the adamantane core, same as the mechanisms of disk shape molecules forming spherical phase structures, the steric hindrance from POSS cages impeded the growth of cylindrical columns, and spherical phase structures could be achieved based on the experimental data of BCC structure appearing. And this type of fabricating spherical phase structures could pave another road to get Frank-Kasper phases with different sizes of spheres.

Design, Synthesis, and Self-assembly of Well-defined Hybrid Materials Including Polymer Amphiphiles and Giant Tetrahedra Molecules Based on POSS Nanoparticles

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Author : Mingjun Huang
Publisher :
ISBN 13 :
Total Pages : 220 pages
Book Rating : 4.:/5 (14 download)

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Book Synopsis Design, Synthesis, and Self-assembly of Well-defined Hybrid Materials Including Polymer Amphiphiles and Giant Tetrahedra Molecules Based on POSS Nanoparticles by : Mingjun Huang

Download or read book Design, Synthesis, and Self-assembly of Well-defined Hybrid Materials Including Polymer Amphiphiles and Giant Tetrahedra Molecules Based on POSS Nanoparticles written by Mingjun Huang and published by . This book was released on 2015 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Bottom-up" techniques-based self-assembly are always attracting people's interests since this technology provides relatively low economic cost and fast route to construct organized structures at different scales. Considering unprecedented benefits from polymer materials, self-assemblies utilizing polymer building blocks have been extensively studied to achieve diverse hierarchical structures and various attractive properties. However, precise controls of chemical primary structures and compositions and exact constructions of hierarchal ordered structures in synthetic polymers are far from being fully appreciated. In this dissertation, a novel approach has been utilized to construct diverse well-defined nano-building blocks, giant molecules, via conjugating different, and functionalized molecular nanoparticles (MNPs) which are shape- and volume-persistent nano-objects with precise molecular structure and specific symmetry. The representative examples of the three basic categories of giant molecules, "giant polyhedra", "giant surfactants", and "giant shape amphiphiles" were discussed in details. First, a class of precisely defined, nanosized giant tetrahedra was constructed by placing different polyhedral oligomeric silsesquioxane (POSS) molecular nanoparticles at the vertices of a rigid tetrahedral framework. Designed symmetry breaking of these giant tetrahedra introduces accurate positional interactions and results in diverse selectively assembled, highly ordered supramolecular lattices including a Frank-Kasper (FK) A15 phase. The FK and quasicrystal phases are originally identified in metal alloys and only sporadically observed in soft matters. It remains unclear how to correlate their stability with the chemical composition and molecular topology in the self-assembling systems. We then for this purpose designed and studied the self-assembly phase transition sequences of four series of hybrid giant surfactants based on hydrophilic POSS cages tethered with one to four polystyrene (PS) tails. With increasing the number of tails, molecular topological variations not only affect phase boundaries in terms of the PS volume fraction, but also open a window to stabilize supramolecular FK and quasicrystal phases in the spherical phase region, demonstrating the critical role of molecular topology in dictating the formation of unconventional supramolecular lattices of "soft" spherical motifs. The FK A15 phase was even surprisingly observed in the giant shape amphiphile molecule, triphenylene-6BPOSS, which has a disk-like flat triphenylene core connected with six hydrophobic POSS cages by sides. Without conical molecular shape, triphenylene-6BPOSS self-assembled and stabilized into supramolecular sphere via p-p interactions through a completely different mechanism with precious two cases. These studies indicate that "bottom-up" self-assemble based on well-defined giant molecules approach can be rather powerful to fabricate usually complicated hierarchical structures and open up a wide field of supramolecular self-assembly with unexpected structure and properties.

Design, Synthesis and Self-assembly of Giant Molecules with Precisely Controlled Heterogeneities, Including Composition, Functionality, Topology and Sequence

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Author : Wei Zhang
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (981 download)

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Book Synopsis Design, Synthesis and Self-assembly of Giant Molecules with Precisely Controlled Heterogeneities, Including Composition, Functionality, Topology and Sequence by : Wei Zhang

Download or read book Design, Synthesis and Self-assembly of Giant Molecules with Precisely Controlled Heterogeneities, Including Composition, Functionality, Topology and Sequence written by Wei Zhang and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In biological systems, it is well-known that the activity and function of biomacromolecules are dictated not only by their primary chemical structures, but also by their secondary, tertiary and quaternary hierarchical structures. Achieving similar levels of control in synthetic macromolecules has yet to be demonstrated. In 1960, Feynman raised a fundamental question: "What would the properties of materials be if we could really arrange the atoms the way we want them?" It is difficult to answer this question at truly atomic level. However, by taking the advantage of the unique giant molecular system recently developed by our group, we are trying to answer it at the "nanoatom" length scale in this dissertation. We started with design, syntheses and crystal structure analyses of three series dyads of sphere-plate giant shape amphiphiles with distinct shapes and precise chemical linkages based on C60-triphenylene (sphere-triangle), C60-perylene diimide (sphere-rectangle) and C60-Porphyrin (sphere-square). We then developed a novel synthetic methodology using orthogonal "click" chemistries, strain-promoted azide-alkyne cycloaddition (SPAAC), oxime ligation and thiol-ene click coupling (TECC), for preparing a library of polystyrene (PS)-polyhedral oligomeric silsesquioxane (POSS) giant surfactants with precisely arranged nano-building blocks. The heterogeneity of primary chemical structure can be precisely controlled and is reflected in the self-assembled supramolecular structures in bulk or in solution. The composition (the volume fraction of hydrophilic "nanoatoms") and functionality are the crucial to determine the assembled structures, illustrated by a series of linear configured PSm-(XPOSS)n. The functionality and topology are also found to affect the assembled structures when the volume fractions are identical, demonstrated by several linear and branched PSm-(XPOSS)n giant surfactants. Furthermore, the sequence effect is explored by comparing the self-assembly behaviors of a pair of sequence isomers. In order to step further answering Feynman's inquire, we extend the synthetic method to prepare truly precise "nanoatom" chains or dendrimers with polydispersity Đ equal to 1, which also form varies order supramolecular structures as we tune their primary chemical structures. Our work offers a promising opportunities to manipulate the hierarchical heterogeneities of giant molecules via precise and modular assemblies of various nano-building blocks, and provides a platform for making precise nanostructures that are not only scientific intriguing but also technologically relevant.

Self-Assembly

Author : Ramanathan Nagarajan
Publisher : John Wiley & Sons
ISBN 13 : 1119001366
Total Pages : 364 pages
Book Rating : 4.1/5 (19 download)

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Book Synopsis Self-Assembly by : Ramanathan Nagarajan

Download or read book Self-Assembly written by Ramanathan Nagarajan and published by John Wiley & Sons. This book was released on 2019-01-07 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: An introduction to the state-of-the-art of the diverse self-assembly systems Self-Assembly: From Surfactants to Nanoparticles provides an effective entry for new researchers into this exciting field while also giving the state of the art assessment of the diverse self-assembling systems for those already engaged in this research. Over the last twenty years, self-assembly has emerged as a distinct science/technology field, going well beyond the classical surfactant and block copolymer molecules, and encompassing much larger and complex molecular, biomolecular and nanoparticle systems. Within its ten chapters, each contributed by pioneers of the respective research topics, the book: Discusses the fundamental physical chemical principles that govern the formation and properties of self-assembled systems Describes important experimental techniques to characterize the properties of self-assembled systems, particularly the nature of molecular organization and structure at the nano, meso or micro scales. Provides the first exhaustive accounting of self-assembly derived from various kinds of biomolecules including peptides, DNA and proteins. Outlines methods of synthesis and functionalization of self-assembled nanoparticles and the further self-assembly of the nanoparticles into one, two or three dimensional materials. Explores numerous potential applications of self-assembled structures including nanomedicine applications of drug delivery, imaging, molecular diagnostics and theranostics, and design of materials to specification such as smart responsive materials and self-healing materials. Highlights the unifying as well as contrasting features of self-assembly, as we move from surfactant molecules to nanoparticles. Written for students and academic and industrial scientists and engineers, by pioneers of the research field, Self-Assembly: From Surfactants to Nanoparticles is a comprehensive resource on diverse self-assembly systems, that is simultaneously introductory as well as the state of the art.

Design, Synthesis and Self-assembly of Polyhedral Oligomeric Silsesquioxane (POSS) Based Hybrid Materials

Author : Ni Bo
Publisher :
ISBN 13 :
Total Pages : 139 pages
Book Rating : 4.:/5 (13 download)

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Book Synopsis Design, Synthesis and Self-assembly of Polyhedral Oligomeric Silsesquioxane (POSS) Based Hybrid Materials by : Ni Bo

Download or read book Design, Synthesis and Self-assembly of Polyhedral Oligomeric Silsesquioxane (POSS) Based Hybrid Materials written by Ni Bo and published by . This book was released on 2018 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: The giant molecules systems exhibit very interesting behaviors in the supramolecular assemblies over the past several years compared to other macromolecular systems. As an old Chinese saying goes "good tools are prerequisites for a successful execution of a job". This dissertation focuses on the synthetic possibilities based on the previous work and try to explore some progress in the first part. The second part of the dissertation encapsulates the self-assembly behaviors of the synthesized giant molecular systems. A pre-functionalization method was developed to achieve giant molecular families with more abundant functionalities. Fluorinated polyhedral oligomeric silsesquioxane (FPOSS), long alkyl chain functionalized POSS (C8POSS), and protected carboxylic acid group functionalized POSS (tAPOSS) were designed and prepared. These kinds of molecules are viewed as molecular nanoparticles (MNPs). The reactivities of the modules was proved by combining them with polymer systems like polystyrene via "click" chemistry. These precisely defined functionalized POSS-containing hybrids could serve as model molecules to investigate the self-assembly behaviors of giant molecules.The solution self-assembly of a giant surfactant consisting of a polystyrene-block-poly (ethylene oxide) (PS-b-PEO) diblock copolymer tail tethered onto a fluorinated polyhedral oligomeric silsesquioxane (FPOSS) cage in 1,4-dioxane/water was investigated. Abundant unconventional micellar structures including toroids, two-dimensional hexagonally patterned colloidal nanosheets, and laterally structured vesicles were observed.2 This study not only exhibits various unique morphologies, but also promotes the fundamental understanding on the pathways of the transformations between different morphologies in the solution self-assembly behavior of giant surfactants.In the MNPs and polymer hybrid systems, the MNPs were with precise molecular weights and chemical compositions. But the polymers used still have a molecular weight distribution which originates from the nature of the polymerization methods applied. To eliminate the polydispersity effect from the system, it is crucial to have molecular systems with precise molecular weights and chemical structures from the physical point of view. Upon this anticipation, we have designed a series of dendrons which are compositionally identical, but their linkers are in different chemical connection geometries. These sets of macromolecules are composed of hydroxyl group functionalized POSS (DPOSS) and isobutyl functionalized POSS (BPOSS). The final dendron structure consists of three parts, one DPOSS at the apex, four BPOSSs at the periphery and the flexible linkers. Note that this series of dendrons is topological isomers. Self-assembled structures of four dendron topological isomers were studied using SAXS and TEM. The results help us to understand the role of linkers in a amphiphiles system and give us some guidance on how to design a molecular system in the future.

Giant Molecules Based on Perylene Dimides: Synthesis, Characterization and Self-assembly Behaviors

Author : Yuyang Ji
Publisher :
ISBN 13 :
Total Pages : 60 pages
Book Rating : 4.:/5 (17 download)

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Book Synopsis Giant Molecules Based on Perylene Dimides: Synthesis, Characterization and Self-assembly Behaviors by : Yuyang Ji

Download or read book Giant Molecules Based on Perylene Dimides: Synthesis, Characterization and Self-assembly Behaviors written by Yuyang Ji and published by . This book was released on 2017 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Designing giant molecules is a rapidly developing research area nowadays. Giant molecules could be connected by different kinds of nanoparticles and thus their chemical structures are well-defined. Common giant molecules, such as giant polyhedral, giant surfactants and giant Janus particles, are able to self-assemble into novel nanostructures with molecular weights as controllable as traditional polymers but much more specific. Organic nanoparticles, such as fullerenes, polyhedral oligomeric silsesquioxanes (POSS), polyoxometalates, perylene diimides (PDI) are widely used in building giant molecules. This work focuses on synthesizing giant molecules based on organic nanoparticles and detecting their self-assembly behaviors in bulk. Four giant molecules have been designed and synthesized: the giant molecule PS2.9K-PDI-DPOSS, the 2PS2.9K-PDI-DPOSS, the PS2.6K-PDI-Hex-ol and the 2PS8K-PDI-Hex-ol. These giant molecules built with PS tails and hydrophilic groups, are able to self-assembled into various nanostructures at different temperature. Characterization was accomplished by 1H NMR and GPC spectra. Self-assembly behaviors in bulk were studied by Small Angle X-ray Scattering (SAXS).

Synthesis and Self-assembly of Star-shape Giant Molecules Based on Hydrophilic Polyhedral Oligomeric Silsesquioxane (POSS)

Author : Gaoyan Mu
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (17 download)

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Book Synopsis Synthesis and Self-assembly of Star-shape Giant Molecules Based on Hydrophilic Polyhedral Oligomeric Silsesquioxane (POSS) by : Gaoyan Mu

Download or read book Synthesis and Self-assembly of Star-shape Giant Molecules Based on Hydrophilic Polyhedral Oligomeric Silsesquioxane (POSS) written by Gaoyan Mu and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The chemical and physical properties of materials are determined not only by composition but also hierarchical structures. Hierarchical structures are formed by "bottom up" method, self-assembly of nano-scale building blocks into supramolecular assemblies via secondary interactions.1 In recent years, a series of functionalized POSS were utilized as "nanoatoms" to synthesize well-defined giant molecules. As a kind of giant molecules, giant surfactants are focused in my work. To investigate the fundamental principles of self-assembly, the giant surfactants with precise molecular structures have been synthesized by clicking "nanoatoms" to flexible polymer tails with controlled molecular weight. Because the self-assemblies of giant surfactants are sensitive to topological structures, a series of "giant surfactant" with multi-heads or multi-tails have been synthesized.2 In my work, the APOSS based star-shape giant molecules with or without polystyrene (PS) tails were precisely synthesized via "living" radical polymerization and "click chemistry". The chemical structure of the product was confirmed by 1H NMR spectrum, 13C NMR spectrum, GPC spectra, FT-IR spectra and MALDI-TOF mass spectra. After the self-assembly of samples in solution, the structures formed were investigated by transmission electron microscopy (TEM), static light scattering (SLS) and dynamic light scattering (DLS).

Synthesis and Self-assembly of Planar Giant Molecules Based on Polyhedral Oligomeric Silsesquioxanes(POSS)

Author : Lun Jin
Publisher :
ISBN 13 :
Total Pages : 52 pages
Book Rating : 4.:/5 (111 download)

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Book Synopsis Synthesis and Self-assembly of Planar Giant Molecules Based on Polyhedral Oligomeric Silsesquioxanes(POSS) by : Lun Jin

Download or read book Synthesis and Self-assembly of Planar Giant Molecules Based on Polyhedral Oligomeric Silsesquioxanes(POSS) written by Lun Jin and published by . This book was released on 2017 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The giant molecule is a kind of macromolecule with high molecular weight and precisely defined chemical structure. The self-assembly behavior of giant molecule can be influenced by intermolecular interactions, such as hydrogen bonding, hydrophobic force, metal coordination, van der Waals forces, pi- pi interactions and electrostatic effects. Besides the chemical interaction, the geometrical factor will also influence the final structure. POSS is a rigid conformation and fixed volume cage molecule with silicon-oxygen backbone. The precisely definable of the functional groups of POSS corresponding to the vertex number makes them fascinating building blocks. In the previous work, it was reported that POSS based three dimensional giant polyhedrons could self-assembly into Frank-Kasper A15 phase. [1] In this thesis, two dimensional planar giant molecules were designed and synthesized to explore novel self-assembly behaviors. Gallic acid derivatives C12 and BPOSS were linked to a simple planar C3 symmetric core, utilizing Sonogashira coupling reaction. By controlling the number of isobutyl-POSS, a series of giant molecules, 3C12-TEB, 2C12-TEB-1BPOSS and 1C12-TEB-2BPOSS were synthesized and studied. This series of target giant molecules were characterized by 1H NMR, 13C NMR, GPC and MALDI-TOF mass spectra. Their physical properties were studied by DSC and temperature-resolved SAXS. Two giant molecules, 2C12-TEB-1BPOSS and 1C12-TEB-2BPOSS, were discovered of hexagonal phase in bulk state.

Design, Synthesis, and Geometry Directed Self-assembly of Oligo-fluorene Based Giant Molecules

Author : Xiaoyun Yan (Chemist)
Publisher :
ISBN 13 :
Total Pages : 293 pages
Book Rating : 4.:/5 (124 download)

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Book Synopsis Design, Synthesis, and Geometry Directed Self-assembly of Oligo-fluorene Based Giant Molecules by : Xiaoyun Yan (Chemist)

Download or read book Design, Synthesis, and Geometry Directed Self-assembly of Oligo-fluorene Based Giant Molecules written by Xiaoyun Yan (Chemist) and published by . This book was released on 2020 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shapes of nano-objects matter significantly during their self-aggregation process. Other than the chemical compositions, people start to recognize such geometric effects of the basic building in all aspect blocks fundamentally drive the system into diverse mesostructures. Huge amount of research effects have been paid in the investigation of geometric effects in physiochemical systems. Depending on their length-scales, the effects lying under the geometry of nano-building blocks are demonstrated in directional interactions, shape-persistent molecules/molecular fragments, and larger nanoparticles/colloids. They are in all dimensions and at all scales, which largely ravel the problem and necessitate a prototype system to be scientifically designed and systematically studied. The molecular LEGO approach, therefore, becomes crucial. This approach was conceptualized by the modular synthesis and precise architecture while constructing the shape determined nano building blocks. By finely altering the functional groups at the atomic level, the yielded molecules would form a systematic library and therefore greatly facilitate the following study towards their self-assembly behaviors. In this dissertation, we would follow this approach to demonstrate the essential features of geometric effects in self-assembly. To grab the pivotal principle of them, we choose a simple shape-persistent fragment-"rod-like" motif and studied its interplay with other geometric units. In the following sections, the detailed experimental methods, conditions, and characterization data are presented. Three general molecular arrangements are adopted: rod-coil, rod-sphere-coil and rod-sphere. Within them, some subtypes of molecular geometries (e.g. I-shaped, T-shaped geometries based on the attachment modes) are also investigated. Based on the morphologies obtained, a strong correlation between the self-assembly behavior and molecular architectures are constructed. For the rod-coil molecules, a propensity to form a layered structure was observed. The introduced rod-like unit largely expend the region of the lamellar phase. For rod-sphere-coil arrangement, since the introduced hydrophilic spherical motifs are bulky, a framework like structure was observed. In this structure, multiple molecules come together to form the molecular bundles which then ligate with each other forming the hexagonally arranged cell. A similar phenomenon was observed in the formation of the novel bicontinuous phase. Based on the highly complex texture captured under TEM, we speculate a novel network like structure was involved. Similarly, when a longer coil part was introduced, a highly asymmetric lamellar structure was formed. To our knowledge, this is the system that achieves the largest asymmetric ratios among all systems. This interesting phase behavior was rationalized by the transition from a double-layered hydrophilic domain to a single-layered hydrophilic domain which entropically stabilizes the structure. In the last, we investigate the self-assembly of rod-sphere conjugates in solution. Novel morphologies, including bilayer vesicles, interdigitated nanosheets, and hexagonally structured colloids were obtained. We attribute the abundant yielded phases by modulating geometric parameters to variant mismatching interfacial areas. From a thermodynamic perspective, the delicate balance between bending energy and interfacial energy determines the final structure. The experimental studies were carried out in either bulk or solution suggesting the principles would be widely applied. Also, these studies indicate that "bottom-up" self-assemble based on well-defined giant molecules approach can be rather powerful to fabricate usually complicated hierarchical structures and open up a wide field of supramolecular self-assembly with unexpected structure and properties.

Design, Synthesis, and Self-assembly of Giant Shape Amphiphiles with Precisely Controlled Compositions, Interactions, and Geometries Via a Molecular Lego Approach

Download Design, Synthesis, and Self-assembly of Giant Shape Amphiphiles with Precisely Controlled Compositions, Interactions, and Geometries Via a Molecular Lego Approach PDF Online Free

Author : Su Zebin
Publisher :
ISBN 13 :
Total Pages : 194 pages
Book Rating : 4.:/5 (126 download)

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Book Synopsis Design, Synthesis, and Self-assembly of Giant Shape Amphiphiles with Precisely Controlled Compositions, Interactions, and Geometries Via a Molecular Lego Approach by : Su Zebin

Download or read book Design, Synthesis, and Self-assembly of Giant Shape Amphiphiles with Precisely Controlled Compositions, Interactions, and Geometries Via a Molecular Lego Approach written by Su Zebin and published by . This book was released on 2019 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-assemblies of soft matters attract broad interests of material scientists since this technology provides versatile designs, relatively low economic cost, convenient route to construct ordered structures at different scales. Tremendous achievements such as various of hierarchical architectures and diverse attracting properties have been achieved by utilizing by self-assemblies of polymer building blocks. However, the challenges of precise controls of designed chemical primary structures, compositions, molecular topology and exact constructions of assembled structures in synthetic polymers are far away from being well addressed. In this dissertation, a novel approach named "molecular Lego approach" has been utilized to construct various well-defined giant molecules, constructed by several types of building blocks, which are nano-sized molecules with precise molecular structure, relatively rigid conformation, and defined molecular symmetry. Three categories of "giant shape amphiphiles" with different driving force for self-assemblies were designed, synthesized, and investigate in detail. First, we designed and synthesized a series of nanosized giant shape amphiphiles in which a triphenylene core is attached to six identical polyhedral oligomeric silsesquioxane (POSS) cages at the periphery through covalent linkers with tunable lengths. Giant shape amphiphiles are molecular building blocks that consist of different moieties of distinct shapes, and engage in competing interactions. The relatively weak [pi-pi] stacking interactions among conjugated aromatic triphenylene cores enable the segregation from peripheric BPOSS cages (POSS functionalized with seven isobutyl groups). Moreover, the tunability of the linker length enables the formation of various ordered spherical phases. Using this platform, we report the experimental observation of the FK Z phase in a soft matter system. Based on these results, we then designed and studied the self-assembly phase transition behaviors of another two series of giant shape amphiphiles. The driving force of these two series of giant shape amphiphiles are only [pi-pi] stacking interactions supplied by triphenylene core, but also hydrogen bonding supplied by the linkers. With systematically tuning the length and rigidity of the linkers, we observed various of phases, including DDQC phase, F-K [sigma] phase, body centered cubic (BCC) phase and HEX phase. Furthermore, we find two sets of giant shape amphiphiles based on benzene-1,3,5-tricarboxamide and cyclotriphosphazene. There is not [pi-pi] stacking interaction between these two types of cores. The driving force for these two sets of samples are mainly hydrogen bonding. These two sets of giant shape amphiphiles self-assemble into BCC phase and A15 phase. These results suggest that the crown shape molecular design is a general way to construct complex spherical phases. These studies suggest that "molecular Lego approach" self-assemblies based on well-defined giant shape amphiphiles can be a powerful platform for achieving unconventional hierarchical structures and pave a new way for supramolecular self-assembly with expected structure, designed properties and function.

Design, Synthesis and Self-assembly of Shape Amphiphiles Based on Polyhedral Oligomeric Silsesquioxane-polymer Conjugates

Author : Kan Yue
Publisher :
ISBN 13 :
Total Pages : 225 pages
Book Rating : 4.:/5 (129 download)

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Book Synopsis Design, Synthesis and Self-assembly of Shape Amphiphiles Based on Polyhedral Oligomeric Silsesquioxane-polymer Conjugates by : Kan Yue

Download or read book Design, Synthesis and Self-assembly of Shape Amphiphiles Based on Polyhedral Oligomeric Silsesquioxane-polymer Conjugates written by Kan Yue and published by . This book was released on 2013 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hierarchally ordered supramolecular structures generated by self-assembly of various nano-materials have attracted great amount of interests due to their potentials in advanced material designs and applications via the "bottom-up" approach. In the field of polymer science, studies on block copolymers and their well-documented micro-phase separation behaviors have been one of the central themes during the past a few decades. The consequentially proposed block copolymer lithography based on these studies is considered as one of alternative solutions to complement the traditional photolithography and further reduce the feature sizes of microelectronic fabrications. However, it is still a grand challenge to achieve micro-phase separated ordered structures with sub-20 nm feature sizes in common block copolymer systems, as well as to obtain unconventional self-assembled ordered phases. It replies on the development of novel materials to resolve these problems. "Shape amphiphiles", constructed by the chemical integration of molecular nano-building blocks with distinct shapes and competing interactions, emerge as a novel class of nano-materials. In this dissertation, the molecular design and synthesis of a library of shape amphiphiles with precisely defined structures based on conjugates of functionalized polyhedral oligomeric silsesquioxanes (POSS) and polystyrene (PS) are presented. These POSS-PS conjugates capture the structural features of small molecule surfactants but represent their size-amplified analogues and are thus, also referred as "giant surfactants". The development of a "sequential click approach" and the utilization of a series of "click adaptor molecules" facilitated the modular and efficient precision synthesis and the feasible structural diversification of molecular architectures for a systematic investigation. It was subsequently revealed that in the bulk state, driven by the nano-phase separation between the functionalized POSS cages and the polymer chains, POSS-based shape amphiphiles can self-assemble into various kinds of ordered supramolecular phases depending on the relative volume fraction of the two components and the molecular topology. The unique structural features of POSS-based shape amphiphiles, such as the shape persistence of the POSS cages and the high x value due to the clustering of functional groups, resulted in an asymmetric phase diagram of ordered structures with sub-10 nm feature sizes. Moreover, self-assembly of these shape amphiphiles exhibited a remarkable sensitivity on the molecular architectures, which resembles the properties of small molecule surfactants rather than the block copolymers. By tuning the molecular architectures, some exceptional phases could be observed, such as an inversed honeycomb phase and a highly asymmetric lamellar phase, as observed in the multi-headed giant surfactant system. Therefore, it is concluded that POSS-based shape amphiphiles provide a versatile platform for advancing our understanding about the self-assembled diverse equilibrium phase structures with sub-20 nm feature sizes.

Synthesis and Self-assembly of Molecular Shape Amphiphiles

Author : Xinfei Yu
Publisher :
ISBN 13 :
Total Pages : 176 pages
Book Rating : 4.:/5 (124 download)

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Book Synopsis Synthesis and Self-assembly of Molecular Shape Amphiphiles by : Xinfei Yu

Download or read book Synthesis and Self-assembly of Molecular Shape Amphiphiles written by Xinfei Yu and published by . This book was released on 2012 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer-tethered nanoparticles are one kind of shape amphiphiles, which are geometric objects with distinct shapes and chemical functionalities. Hydrophilic polyhedral oligomeric silsesquioxane (POSS) and fullerene (C60) are utilized as model nanoparticles while hydrophobic polystyrene (PS) chains are used as tetheres to construct model molecular shape amphiphiles.PS-tethered carboxylic acid functionalized POSS with different PS chain lengths, PSN-APOSS, were synthesized by combining anionic polymerization and thiol-ene "click" chemistry. PSN-APOSS formed micelles in selective solvents which were studied by transmission electron microscopy (TEM) and light scattering (LS) experiments. The effects of PS chain length, common solvents, and solvent/nonsolvent ratio on the micellar morphologies of PSN-APOSS have been investigated. The multivalent interactions between APOSS cages with fixed shape and volume made the self-assembly behaviors of PSN-APOSS distinct from those of traditional amphiphilic block copolymers. The self-assembled ordered structures of PSN-APOSS in the condensed state were studied by small angle X-ray scattering (SAXS) and TEM experiments. The ordered structures changed from lamellae, to hexagonal packed cylinders, and to body-centered cubic spheres as increasing PS chain length. The size of self-assembled structure is around 10 nm, which is challenging for traditional diblock copolymers. 1,3-Dipolar Huisgen cycloaddition of alkyne-azide "click" reaction was utilized to synthesize the PS mono- and di-tethered hydrophilic C60 (PSN-AC60 and 2PSN-AC60) with well-controlled topology and various PS chain lengths. Self-assembled aggregates (micelles and colloidal particles) of these shape amphiphiles were prepared in solutions and studied by TEM and LS experiments. A systematic morphological phase diagram for PSN-AC60 was obtained depending on the molecular concentration, PS chain length, and solvent composition. Concentration-sensitive self-assembled morphologies were ascribed to multivalent interactions between AC60 nanoparticles as well as the PS chain stretching. The topology effect on the formation of both micelles and colloidal particles was revealed by PS44-AC60 and 2PS2323-AC60, which have identical PS weight fractions. These giant molecular shape amphiphiles thus represent a novel class of amphiphilic molecules that have not been systematically explored beyond the traditional surfactants and block copolymers systems, which provide a new platform for understanding supramolecular self-assemblies of amphiphilic molecules in solution and in condensed state.

Giant Molecule Based Nanostructured Materials

Author : Qingyun Guo
Publisher :
ISBN 13 :
Total Pages : 207 pages
Book Rating : 4.:/5 (124 download)

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Book Synopsis Giant Molecule Based Nanostructured Materials by : Qingyun Guo

Download or read book Giant Molecule Based Nanostructured Materials written by Qingyun Guo and published by . This book was released on 2020 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-assembly of macromolecules have made significant progresses in the past decades in creating ordered structures on the nanometer scale, which is of not only scientific but also technological importance. Diverse types of macromolecules, including block copolymers, dendrimers and giant molecules, have been used to construct well-ordered nanostructures. Our group is continuously working on constructing materials with ordered nanostructures based on self-assembly of giant molecules composed of chemically precise and shape-persistent molecular nanoparticles. A series of usual and unusual supramolecular nanostructures have been obtained experimentally.My dissertation will focus on functionality aspect of giant molecule-based materials. First, a series of cylindrical and spherical phases was obtained by self-assembly of amphiphilic giant dendrons. Then, an unusual phase separation between non-polar molecular nanoparticles with polystyrene induced by fluorinated POSS was demonstrated. The functionality scope of molecular nanoparticles was also expanded by introducing ferrocene units and a series of well-ordered organometallic nanostructures were prepared. In the last two chapters of this dissertation, preparing mesoporous ceramic materials with well-ordered nanostructures were focused. By pyrolyzing single-sourced POSS-polystyrene conjugates, ordered mesoporous ceramic materials with different functionalities can be obtained.

Hierarchical Supramolecular Structures Based on Molecular Nanoparticles from Bulk to Thin Film State

Author : Chih-Hao Hsu
Publisher :
ISBN 13 :
Total Pages : 239 pages
Book Rating : 4.:/5 (129 download)

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Book Synopsis Hierarchical Supramolecular Structures Based on Molecular Nanoparticles from Bulk to Thin Film State by : Chih-Hao Hsu

Download or read book Hierarchical Supramolecular Structures Based on Molecular Nanoparticles from Bulk to Thin Film State written by Chih-Hao Hsu and published by . This book was released on 2014 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular nanoparticles (MNPs), such as [60]fullerene (C60), polyhedral oligomeric silsesquioxane (POSS), and polyoxometalate (POM), are nano-objects possessing shape- and volume-persistency and precisely defined molecular structure with specific symmetry. Because of their inherent physical properties and the feasible functionalization, MNPs have been considered as a unique class of building blocks for nanomaterials to bridge the molecular functionalities and material properties across different length scales through supramolecular hierarchical structures. The well-developed "click chemistry" in our group facilitates a diverse molecular design of "giant molecules" consisted of MNPs as building blocks, such as giant shape amphiphiles, giant polyhedron, and giant surfactants. The purpose of this research is to study the formation of hierarchical structures and transition behaviors of giant molecules in bulk and thin film states to reveal the structure formation mechanisms and to further build up the understanding of dependencies of the molecular architectures, topologies, and volume fraction of building blocks on the self-assembled supramolecular structures. The supramolecular hierarchical structures and phase behaviors of two giant shape amphiphiles, C60-C8-C12 and BPOSS-LIND, in bulk were studied and both of them were found to form layered structures because of their commensurate building blocks in size. In addition, the first study on the supramolecular structure of a giant polyhedron, C-tetra-BPOSS, was conducted and found it forms a cylinder-like supramolecular structure induced by the molecular architecture and the crystallization of BPOSS cages. Finally, the self-assembled morphologies of 3-component AC60-based and FPOSS-based giant surfactants in thin films were studied, especially the morphological transition with volume fractions change and the topological effect on the morphologies. Because of the affinities of the building blocks, AC60-based giant surfactants are analogues of ABA-type terpolymers and form 2-component morphologies while FPOSS-based ones are analogues of ABC-type terpolymers and form 3-component morphologies. In general, the self-assembled structures of these giant molecules are profoundly affected by the physical interactions among MNPs. The molecular architectures and the selection and proportion of counter parts in a molecule have been proved able to fine tune the supramolecular structures. These understanding of self-assembly of giant molecules allow us to modularly develop novel nanomaterials with desired supramolecular structures consist of specific MNPs of targeting properties.

Macromolecular Structure Evolution of Giant Molecules Via "click" Chemistry

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Author : Hao Su
Publisher :
ISBN 13 :
Total Pages : 39 pages
Book Rating : 4.:/5 (882 download)

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Book Synopsis Macromolecular Structure Evolution of Giant Molecules Via "click" Chemistry by : Hao Su

Download or read book Macromolecular Structure Evolution of Giant Molecules Via "click" Chemistry written by Hao Su and published by . This book was released on 2014 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physical properties of giant molecules are intimately dependent upon their primary chemical structures and molecular topologies and thus, precise controls of these structures and topologies are an important pursuit in developing new functional materials. In this paper, we report the rational molecular design and cascading "click" synthesis of three types of polyhedral oligomeric silsesquioxane (POSS)-based asymmetric giant gemini surfactants (AGGSs) including (1) consisting of two polymer tails differing in chain lengths and two identical heads, (2) having two distinct functional heads and two similar tails, and (3) possessing two tails of different lengths and two distinct head groups. The syntheses were achieved in a convenient, efficient, and modular way, allowing the precise control and rigorous tuning of both of polymer tail composition and POSS surface chemistry in these AGGSs. The synthetic processes can be rapidly accomplished within about 5 hours and only require non-chromatographic purification. Our study expands the scope of synthetically available giant surfactants along with the route of macromolecular structure evolution of giant molecules inspired by further decreasing the symmetry of POSS-based giant molecules using "click" chemistry.

Synthesis of Polystyrene (PS)-polyhedral Oligomeric Silsesquioxane (POSS)-based Giant Molecules with Sequence-controlled POSS Heads

Author : Siyu Zhang
Publisher :
ISBN 13 :
Total Pages : 35 pages
Book Rating : 4.:/5 (112 download)

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Book Synopsis Synthesis of Polystyrene (PS)-polyhedral Oligomeric Silsesquioxane (POSS)-based Giant Molecules with Sequence-controlled POSS Heads by : Siyu Zhang

Download or read book Synthesis of Polystyrene (PS)-polyhedral Oligomeric Silsesquioxane (POSS)-based Giant Molecules with Sequence-controlled POSS Heads written by Siyu Zhang and published by . This book was released on 2016 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design and the synthesis of sequence-controlled linear giant molecules by controlling the sequences and functionalities precisely are great challenges in the field of macromolecular chemistry. In this article, we designed a method to synthesize sequence-controlled linear giant molecules by using two different kinds of polyhedral oligomeric silsesquioxanes (POSSes) based building blocks. Five POSSes heads were attached successively and alternately as a linear chain with a polystyrene tail as a purification tag via azide-alkyne cycloaddition (SPAAC) "click" reactions, oxime ligations, and thiol-ene "click" coupling (TECC). In order to precisely test controlled sequences and functionalities of the POSSes heads, we used many different characterizations, 1HNMR spectra, 13CNMR spectra, FT-IR spectra, UV-vis spectra, and GPC traces, to characterize every precursor of the giant molecules. 1HNMR and 13CNMR also showed the change of the vinyl groups on VPOSSes after TECC reactions. This study pioneers the synthesis for giant molecules with accurately controlled sequences, functionalities, compositions, and topologies. Furthermore, these features defined giant molecules can also be used to test several specific supermolecular self-assembling behaviors.

Self-assemble of Novel Discotic Nano-molecules Based on Polyhedraloligomericsilsesquioxanes

Author : Mingxuan Li
Publisher :
ISBN 13 :
Total Pages : 44 pages
Book Rating : 4.:/5 (883 download)

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Book Synopsis Self-assemble of Novel Discotic Nano-molecules Based on Polyhedraloligomericsilsesquioxanes by : Mingxuan Li

Download or read book Self-assemble of Novel Discotic Nano-molecules Based on Polyhedraloligomericsilsesquioxanes written by Mingxuan Li and published by . This book was released on 2014 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Self-assembly is a process that components automatically form order patterns without any human intervention.1 The molecular self-assemble, including especially so called crystal engineering, has provided numerous of novel hierarchical structures with exceptional properties.2 However, due to their relatively small size, the intermolecular interactions play the vital role in the assemble process while the geometry effect is usually neglected. Recent studies of colloidal particles with size between tens of nanometers to several micrometers proved the significance of shape in the self arrangement of the molecules. Herein, we seek to engineer the self-assemble utilizing giant molecules which have precise chemical structure, symmetric discotic shape, and specially several nanometer size filling the gap between small molecules and colloidal particles. In this work, two novel discotic nano-molecules or so call giant molecules were successfully synthesized by connecting three POSS and six POSS to Truxene and Triphenylenecore respectively utilizing "Huisgen Cyclo addition" click reaction. Crystal structure of the giant molecule having three POSS attached to Truxene core was carefully investigated through X-ray diffraction and transmission electron microscope (TEM) diffraction. While for the giant molecule with six POSS cages attached to Triphenylene core, surprisingly it could show distinct self-assembly behavior in which A15 phase structure was found when POSS was not crystallized. This work could not only provide the detailed analysis of crystal structure and unusual A15 phase structure, but more importantly, deepen our understanding of intermolecular interaction and shape effect on hierarchical structures based on such simple discotic giant molecules.