Honeycomb‐Patterned Photoluminescent Films Fabricated by Self‐Assembly of Hyperbranched Polymers

Abstract

Honeycomb-patterned films made by the self-assembly of polymers have aroused increasing interest because of their fascinating morphology and potential applications. [1][2][3] Although much of the work has focused on linear [1][2][3][4][5][6][7][8][9][10][11][12][13] and star-shaped [1,4] macromolecules, the use of dendritic polymers, with their three-dimensional architectures and unique properties, significantly enlarges the structural diversity and makes multifunctional self-assembly accessible.[14] The combination of supramolecular chemistry and nanotechnology has recently offered an alternative approach to functional selfassembly. Quantum dots (for example, CdSe) [3] and fullerenes [15] have been mixed with polymers to fabricate luminescent honeycomb films. However, the dispersibility of nanomaterials in a polymer matrix is limited, which results in their random distribution in the organized films. It is quite difficult to achieve a dispersion of one substance in another one at a molecular level simply by mixing because of aggregation. To meet this challenge and explore a new area of functional self-assembly, we have shifted our attention from conventional linear macromolecules to hyperbranched polymers.Hyperbranched polymers play a very important role in self-assembly and greatly enrich the range of host materials and building blocks that can be used in supramolecular chemistry. [14,[16][17][18] So far, nanofibers, [16] giant vesicles, [17] and visible tubes [18] have been obtained by the self-assembly of amphiphilic hyperbranched polymers in a solvent. Intriguingly, a core-shell amphiphilic dendritic macromolecule can be regarded as a unimolecular micelle or nanobox [19][20][21] in which small guests, such as dyes, quantum dots, and noble metals, can be loaded. [21][22][23] This property generates the ability for the molecular-level dispersion and distribution of one or even more substances in another one. Accordingly, multifunctional assembled structures would be expected to have applications as the junctions of honeycomb patterned films, in dendritic polymers, and in host-guest chemistry. Herein, we report that honeycomb-patterned films with thicknesses ranging from tens of nanometers to micrometers can be prepared by the molecular self-assembly of amphiphilic hyperbranched poly(amidoamine)s (HPAMAMs). Moreover, the HPAMAMs can encapsulate dye molecules to form colorful host-guest supramolecular complexes. Various luminescent honeycomb-patterned films with tunable emission wavelengths (l em ) were prepared by subsequent nonmolecular self-assembly of the complex on substrates.An amphiphilic hyperbranched polymer, poly(amidoamine) modified with palmitoyl chloride (HPAMAM10K-C16; see the Supporting Information), [23] was chosen as the first material for the construction of the porous films. The films were prepared by dropping a solution of the HPA-MAM10K-C16 in chloroform on to a cleaned substrate (for example, a silicon wafer, quartz, mica, etc.) and then analyzed by SEM, AFM, TEM, and optical fluorescence m...

Self‐Assembly of Hyperbranched Polymers and Its Biomedical Applications

“…We synthesized a series of amphiphilic hyperbranched poly(amido-amine)s (HPAMAMs) modifi ed with palmitoyl groups (HPAMAMs-C 16 ). [ 65 ] With the solvent evaporation of a drop of the polymer chloroform solution onto a cleaned substrate (for example, silicon wafer, quartz, mica, etc. ), very regular honeycomb-patterned porous fi lms with uniform ( < 2% defects) hexagon holes 5-6 μ m in width were obtained ( Figure 6 ).…”

Breath-Figures Self-Assembly, the Versatile Method of Manufacturing Membranes and Porous Structures: Physical, Chemical and Technological Aspects

“…At first, it was suggested that star-like and hyperbranched polymers promote formation of well-ordered structures [26,42], however, later it was demonstrated that linear polymers also give rise to the patterns, typical for the breath-figures self-assembly, such as depicted in Figure 2 [40][41]. It was suggested that coiled polymers (polystyrene) promote formation of breath-figures patterns [42]; on the other hand, rigid-rod conjugated polymers also gave rise to wellordered honeycomb reliefs [36]. The impact of the molecular weight of the polymer on the resulting pattern remains obscure, and the data reported by various groups are controversial [44][45][46].…”

“…However, the experimental data related to the impact of the substrate on the breath-figures self-assembly remain scarce [42,[61][62][64][65]. Valiayaveettil and co-workers used clean glass, epoxy, amine terminated and dendrimer functionalized glass as well as silicon wafers to cast a poly(p-phenylene) with pyridine chloroform solution [65].…”

Autofluorescent Hyperbranched Poly(amide amine) as Effective Fluorescent Probe for Label-free Detection of Copper(II) Ions

“…Moreover, the hyperbranched poly(amide amine) (HPAMAM) has been reported to emit striking fluorescence. 28,29 In particular, HPAMAM, a water-soluble, environmentally friendly and autofluorescent polymer without doping an external fluorochrome, is a cationic polymer containing many amino groups, and it has been used as polyvalence ligand to modify and stabilize some metal ions via chelation. It has been reported that HPAMAM can capture free copper(II) ions efficiently.…”