Ming-Chia Li

National Chiao Tung University | NCTU · Department of Biological Science and Technology

This work aims to examine the effect of self-assembly on the chiroptic responses of the achiral block copolymer (BCP) polystyrene-b-poly(ethylene oxide) (PS-b-PEO) associated with chiral luminophores, (R)- or (S)-1,1′-bi-2-naphthol ((R)- or (S)-BINOL), through hydrogen bonding. With the formation of a well-ordered helical phase (H*), significantly...

Circularly polarized luminescence (CPL) is typically achieved with a chiral luminophore. However, using a helical nanosized fused quartz cell consisting of chiral silica, we could control the wavelength and helical sense of the CPL of an achiral luminophore. Chiral silica with a helical nanostructure was prepared by calcining a mixture of polyhedra...

This paper presents a facile method for fabricating a thin-film sample with a high asymmetry value of induced circularly polarized luminescence (iCPL) (|glum| = 2.0 × 10-3). The method involves mixing stereoregular poly(methyl methacrylate) (PMMA) and chiral chromophore (2,2,2-trifluoro-1-(9-anthryl)ethanol (TFAE)) to form a complex with a dynamic...

Background: The two ends of arteriovenous graft (AVG) are anastomosed to the upper limb vessels by surgery for hemodialysis therapy. However, the size of upper limb vessels varies to a large extent among different individuals. Methods: According to the shape and size of neck vessels quantified from the preoperative computed tomography angiograph...

A novel block copolymer containing polyhedral oligomeric silsesquioxanes (POSS) features a well-controlled stereoregularity, that is, isotactic polymethacrylate-functionalized POSS-b-polymethyl methacrylate (it-PMAPOSS-b-PMMA), was prepared via controlled-anionic polymerization. The stereoregularity of each segment in the it-PMAPOSS-b-PMMA is evalu...

A strategy to obtain chiral silica using an achiral stereoregular polymer with polyhedral oligomeric silsesquioxane (POSS) side chains is described herein. The preferred helical conformation of the POSS-containing polymer could be achieved by mixing isotactic polymethacrylate-functionalized POSS (it-PMAPOSS) and a chiral dopant. The array structure...

The juxta-anastomotic stenosis of an arteriovenous fistula (AVF) is a significant clinical problem in hemodialysis patients with no effective treatment. Previous studies of AV anastomotic angles on hemodynamics and vascular wall injury were based on computational fluid dynamics (CFD) simulations using standardized AVF geometry, not the real-world p...

It has been well studied that the surface topography affects the growth and development of neurons. However, the precise mechanism that the surface topography leads to cellular changes remains unknown. In this study, we created an anisotropic surface using nanodiamonds and discovered this surface topography accelerates the development of primary ne...

The formation of helical assembles from achiral supramacromolecules has been a highly mysterious process, but is of interest for the generation of rich structures and properties. Herein, novel hierarchical superhelices are developed from self-assembly of achiral dendron-jacketed block copolymers (DJBCPs). The presence of focal asymmetry in both the...

Surface topography has a profound effect on the development of the nervous system, such as neuronal differentiation and morphogenesis. While the interaction of neurons and the surface topography of their local environment is well characterized, the neuron–topography interaction during the regeneration process remains largely unknown. To address thi...

Hemodialysis is an efficient treatment for kidney failure; the access is a surgically created vein used to remove and return blood during hemodialysis. There are two types of vascular access designed for long-term use, namely the arteriovenous fistula (AVF) and the arteriovenous graft (AVG). However, the AV graft, either by AVF or AVG, would also r...

Optic neuropathies, such as glaucoma and Leber’s hereditary optic neuropathy (LHON) lead to retinal ganglion cell (RGC) loss and therefore motivate the application of transplantation technique into disease therapy. However, it is a challenge to direct the transplanted optic nerve axons to the correct location of the retina. The use of appropriate s...

Here, we show the induced chirality of an achiral chromophoric dye as a joint of polylactide-containing chiral block copolymers (BCPs*) driven by self-assembly, giving the achiral dyes preferentially arranged in a one-handed helical array at the microphase-separated interface. This helical arrangement of the achiral dyes can be “memorized” after hy...

Threading of a poly(ethylene glycol) (PEG) chain linked to a perylenediimide unit at one end with a bulky stopper at the other end through an inner cavity of a bisporphyrin-based doublestranded spiroborate helicate was remarkably accelerated in a specific solvent, in which the PEG chain enfolded sodium cations coordinating to the negatively charged...

Banded spherulite resulting from lamellar twisting due to the imbalanced stresses at opposite fold surfaces can be formed by isothermal crystallization of chiral polylactide and its blends with poly(ethylene glycol) (PEG). Using a polarized light microscope, the handedness of the twisted lamella in banded spherulite is determined. With the same gro...

Herein, enantiomeric polylactide-containing chiral block copolymers (BCPs*) with aliphatic and aromatic junctions are designed and synthesized for investigating the impact of junction π–π interactions on the self-assembly of BCPs*. A profound effect on the microphase separation of the BCP* can be found by introducing the π–π interaction of junction...

The significance of chirality transfer is not only involved in biological systems, such as the origin of homochiral structures in life but also in man-made chemicals and materials. How the chiral bias transfers from molecular level (molecular chirality) to helical chain (conformational chirality) and then to helical superstructure or phase (hierarc...

We present a study of light-emitting diodes (LEDs) using organic fluorescent dyes to replace the general phosphor. The blue die with a specific organic fluorescent dye gives the LED a single color appearance. Through a color-mixing cavity, multiple LEDs are used to produce a quasisolar spectrum at a certain band and white light with a color renderi...

This article deals with the chirality transfer of chiral polymers and chiral block copolymers (BCPs*) on different length scales. Helical conformation can form at the molecular level due to the stereoregularity of chiral entities in the chiral polymers and the BCPs*. Helical superstructures and phases can be fabricated by self-assembling polymer ch...

Banded spherulites are formed by crystallization of a chiral polymer that is end-capped with chromophore. Induced circular dichroism (ICD) of the chromophore can be found in the crystallized chiral polymers, giving exclusive optical response of the ICD. The ICD signals are presumed to be driven by the lamellar twisting in the crystalline spherulite...

Disclosed is a method of patterning a layered material. A layered material is provided, and a photoresist layer is formed thereon. The photoresist layer is patterned by a focused laser beam to expose a part of the layered material. The exposed layered material is etched to pattern the layered material.

Here, we develop a method to fabricate stimuli-responsive color films using block copolymer, poly(4-vinylpyridine)-b-poly(ε-caprolactone) (P4VP-PCL), as a template complexed with functionalized chromophores. The P4VP block in the P4VP-PCL can be associated with cyano end-capped chromophore via charge transfer, which is a secondary force that can be...

Here, we aim to systematically examine the mechanism of photo-induced pyrene association in pyrene-labeled polymers (PLPs) for optical recording. By taking advantage of polymer glass transition, the associated pyrene moieties can be frozen in the glassy matrix of the PLP to give the emission contrast for optical recording, as evidenced by the pheno...

This work presents a simple method to generate ordered chromophore/dispersant nanoarrays through a pore-filling process for nanoporous polymer template to enhance chromophore luminescence. Fluorescence results combining with the morphological evolution examined by scanning probe microscopy reveal that the enhanced luminescence intensity reaches the...

Here, we report the mechanisms of chiral transfer at various length scales in the self-assembly of enantiomeric chiral block copolymers (BCPs*). We show the evolution of homochirality from molecular chirality into phase chirality in the self-assembly of the BCPs*. The chirality of the molecule in the BCP* is identified from circular dichroism (CD)...

A new technology called thermal mode lithography for developing new thermal mode photoresists with temperature sensitive characteristics has been investigated. In this study, we synthesized four types of polymethine compounds that can be applied to thermal mode photoresists. The photo UV absorption and thermal properties are the important character...

Stereoregular vinyl polymers, poly(2-vinyl pyridine)s (P2VPs), were synthesized to examine the tacticity effect on the induced circular dichroism (ICD) via association with chiral acids. The ICD was found to be strongly dependent on the isotacticity of the P2VPs and the acidity of chiral acid in addition to its bulkiness.

A series of poly(4-vinylpyridine)-b-poly(ε-caprolactone) (P4VP-PCL) diblock copolymers have been synthesized and used for the formation of nanostructures with tunable colors arising from the association of chromophores with P4VP block in P4VP-PCL. The association of chromophores leads to the bathochromical shifts of charge transfer absorption peaks...

A series of pyrene-labeled polymers have been synthesized for optical recording. Through the manipulation of polymer chain mobility, resulting in the control of intermolecular distance between pyrene molecules so as to produce static excimers useful for emission contrast formation, the optical recording of PLPs can be well defined.

A series of semicrystalline block copolymers (BCPs), poly(4-vinylpyridine)-block-poly(ε-caprolactone) (P4VP-PCL), with lamellar phases have been synthesized. P4VP-PCL BCP thin films with large-scale, oriented lamellar microdomains were obtained by rimming coating process followed by oscillated shearing using a homemade shear device. Owing to the vi...

The subwavelength structures in optical discs are applied to improve the light trapping effect for solar cell applications. With the proposed configuration, the reflection and absorption efficiencies can be effectively decreased and enhanced, respectively.

A novel intramolecular charge transfer complex---cyanine-7,7,8,8,8-tetracyanoquinodimethane (TCNQ) dye was formed by grafting. The cyanine-TCNQ complex was characterized by UV-vis spectroscopy, fluorescence emission spectroscopy, and magnetic techniques. The optical properties of the cyanine-TCNQ dye, which forms an intramolecular charge transfer c...

We propose a three-dimensional optical storage medium in which a confocal laser-scanning microscopy is applied for multilayer fluorescence readout. The contrast of signal intensity for inside and outside of the pit can reach 71%.

In the experiment of antiphotofading of DVD-R optical recording disc, a 3000 W xenon light (λ=420 nm) was adopted for testing the parameters of a novel cyanine-TCNQ (tetracyanoquinodimethane) charge transfer complex as a recording layer. Its performance without addition of a singlet oxygen quencher under illumination of 1200 min still satisfies wit...