Rigid stars: properties and functions

Heitz, Walter; Meckel-Jonas, Claudia; Neuhaus, Ralf; Roth, Mark D.; Stümpflen, Volker; Wendorff, Joachim H.

doi:10.1002/(sici)1099-1581(199809)9:9<549::aid-pat808>3.0.co;2-3

Cited by 2 publications

(6 citation statements)

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“…Summing up, experiments by us and other groups as well as simulations show that, contrary to expectations raised by the pioneering papers in this fi eld, [ 29,30 ] uncoated TP structures are not compatible with melts of fl exible polymers. However, they can be made compatible by grafting suitable polymers onto them.…”

Section: Infl Uence Of Branching On the Dispersibility Of Ncs In Polycontrasting

confidence: 60%

“…[ 16 ] In this paper, we will focus on the simplest space-fi lling geometry, branched tetrapods (TPs). These nanoparticles have originally been suggested for use as fi ller particles for mechanical reinforcement of fl exible polymers, [ 29,30 ] and they have also been applied in solar cells. [ 20,117 ] In the context of semiconducting materials, TPs are interesting because they can promote charge transport in all three spatial directions, regardless of the orientation of the TPs.…”

Section: Infl Uence Of Branching On the Dispersibility Of Ncs In Polymentioning

confidence: 99%

“…Nanocomposites have been investigated in detail concerning e.g. “molecular reinforcement” (the distribution of fibers in flexible polymers) or the placement of inorganic nanoparticles in block copolymer structures . Numerous investigations in the field of nanocomposites have been carried out motivated by promising observations such as significant property changes at very low volume fractions of the added nanoparticles and the possibility to incorporate new functions through the integration of nanoparticles providing specific properties .…”

Section: Introductionmentioning

confidence: 99%

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Morphology Control in Biphasic Hybrid Systems of Semiconducting Materials

Mathias

Fokina

Landfester

et al. 2015

Macromol. Rapid Commun.

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Simple blends of inorganic nanocrystals and organic (semiconducting) polymers usually lead to macroscopic segregation. Thus, such blends typically exhibit inferior properties than expected. To overcome the problem of segregation, polymer coated nanocrystals (nanocomposites) have been developed. Such nanocomposites are highly miscible within the polymer matrix. In this Review, a summary of synthetic approaches to achieve stable nanocomposites in a semiconducting polymer matrix is presented. Furthermore, a theoretical background as well as an overview concerning morphology control of inorganic NCs in polymer matrices are provided. In addition, the morphologic behavior of highly anisotropic nanoparticles (i.e. liquid crystalline phase formation of nanorod-composites) and branched nanoparticles (spatial orientation of tetrapods) is described. Finally, the morphology requirements for the application of inorganic/organic hybrid systems in light emitting diodes and solar cells are discussed, and potential solutions to achieve the required morphologies are provided.

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Section: Infl Uence Of Branching On the Dispersibility Of Ncs In Polycontrasting

confidence: 60%

Section: Infl Uence Of Branching On the Dispersibility Of Ncs In Polymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Morphology Control in Biphasic Hybrid Systems of Semiconducting Materials

Mathias

Fokina

Landfester

et al. 2015

Macromol. Rapid Commun.

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“…Creating a well‐defined and percolated morphology at the nanoscale of two different materials is challenging. This topic has been discussed intensively concerning “molecular reinforcement" (the distribution of fibers in flexible polymers) or the placement of inorganic nanoparticles in block‐copolymer structures . It is particularly essential in optoelectronic devices such as organic solar cells, which require bicontinous structures to efficiently transport holes and electrones to relevant electrodes.…”

Section: Introductionmentioning

confidence: 99%

“…In this respect, branched space‐filling tetrapods (TPs) are more promising, as they offer a potential for charge transport in all the spatial directions independent of their orientation . In addition, rigid tetrahedral structures have been investigated in detail for the mechanical reinforcement of flexible polymers . Preliminary lattice calculations performed in this context suggested that rigid TPs are more compatible with flexible polymer chains than rigid rods (Figure in ref.…”

Section: Introductionmentioning

confidence: 99%

Strategy for Good Dispersion of Well‐Defined Tetrapods in Semiconducting Polymer Matrices

Lim

Borg

Dolezel

et al. 2014

Macromol. Rapid Commun.

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The morphology or dispersion control in inorganic/organic hybrid systems is studied, which consist of monodisperse CdSe tetrapods (TPs) with grafted semiconducting block copolymers with excess polymers of the same type. Tetrapod arm-length and amount of polymer loading are varied in order to find the ideal morphology for hybrid solar cells. Additionally, polymers without anchor groups are mixed with the TPs to study the effect of such anchor groups on the hybrid morphology. A numerical model is developed and Monte Carlo simulations to study the basis of compatibility or dispersibility of TPs in polymer matrices are performed. The simulations show that bare TPs tend to form clusters in the matrix of excess polymers. The clustering is significantly reduced after grafting polymer chains to the TPs, which is confirmed experimentally. Transmission electron microscopy reveals that the block copolymer-TP mixtures ("hybrids") show much better film qualities and TP distributions within the films when compared with the homopolymer-TP mixtures ("blends"), representing massive aggregations and cracks in the films. This grafting-to approach for the modification of TPs significantly improves the dispersion of the TPs in matrices of "excess" polymers up to the arm length of 100 nm.

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Rigid stars: properties and functions

Cited by 2 publications

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Morphology Control in Biphasic Hybrid Systems of Semiconducting Materials

Morphology Control in Biphasic Hybrid Systems of Semiconducting Materials

Strategy for Good Dispersion of Well‐Defined Tetrapods in Semiconducting Polymer Matrices

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