Cheng-Hao Samuel Lee

• PhD
• Senior Scientific Officer at The Hong Kong Polytechnic University

Disperse dyes are categorized based on their energy levels and are utilized in conjunction with reactive dyes for the dyeing of polyester/cotton fibres in two distinct compositional ratios. The dyeing conditions and the colour fastness properties of the dyed materials are intrinsically linked to this classification. The application of reverse micel...

The feasibility of using different forms of limonene biosolvents as dyeing medium in rhamnolipid (RL) biosurfactant-based reverse micellar dyeing system for cotton fabrics is investigated, with different dyeing profiles. Experimental results reveal that limonene-dyed fabrics can achieve generally higher colour yield than water-dyed fabrics while sa...

Enhancing the degradability of polyethylene plastics could provide a potential solution to the overwhelming crisis of plastic waste. Conventional studies have focused on the degradation of polyethylene thin films. This study investigated UV-induced photo-degradation according to ASTM D5208-14 in polyethylene sheets with thicknesses ranging from 0.4...

Influence of color fixation agent (CFA) and dyebath pH in secondary alcohol ethoxylate (SAE)-based reverse micellar dyeing system of cotton with reactive dyes was investigated and compared with water-based dyeing system using different alkali (i.e. CFA) such as: (i) sodium bicarbonate (NaHCO3), (ii) sodium carbonate (Na2CO3) and (iii) sodium hydrox...

Hemp fiber, recognized for its eco-friendliness, wide availability, and biodegradability, stands as a renewable resource with promising applications. To fully harness its potential, it is crucial to study the relationship between chitosan concentration and both the mechanical and thermal properties of hemp fiber. Understanding these effects can pro...

Robust, hydrophobic woven cotton fabrics were obtained through the sol–gel dip coating of two different nanoparticle (NP) architectures; silica and silica-ZnO. Water repellency values as high as 148° and relatively low tilt angles for fibrous fabrics (12°) were observed, without the need for fluorinated components. In all cases, this enhanced funct...

A large number of non-degradable materials have severely damaged the ecological environment. Now, people are increasingly pursuing the use of environmentally friendly materials to replace traditional chemical materials. Polyhydroxyalkonates (PHAs) are receiving increasing attention because of the unique biodegradability and biocompatibility they of...

This study investigates the feasibility of using biodegradable secondary alcohol ethoxylate (SAE) non-ionic surfactant as a building block for the formation of reverse micelles, functioning as reactive dye carriers for the dyeing of cotton fabric in non-aqueous octane medium. Ten dyeing parameters were optimised, by a one-factor-at-a-time approach,...

Feasibility and applicability of rhamnolipid (RL) microbial biosurfactant-based reverse micellar non-aqueous system in different solvent medium for dyeing of cotton fabrics was investigated. In this study, several solvents, including heptane, octane, nonane, decamethylcyclopentasiloxane (D5), and paraffin liquid (PL), were chosen as the dyeing medi...

Reactive dyes of three primary colours used for exhaustion dyeing of cotton fabric in conventional water dyeing system and APG-based reverse micelle dyeing system, with D5 and alkane solvents as dyeing medium, were investigated. Calibration curves of both systems were established. Absorbance and dye concentration were found to be directly correlate...

The feasibility of computer colour matching (CCM) of rhamnolipid-based reverse micellar dyeing system on cotton fibre in octane media has been investigated and compared with that of conventional water-based dyeing system. Calibration results confirm that the calibration curves of both systems are linear in structure. Reflectance curves reveal that...

The viability of reverse micelles, using rhamnolipid (RL) microbial biosurfactant as the building block, for dyeing of cotton fabrics with reactive dyes has been studied. This novel and sustainable dyeing system not only can achieve salt-free, but also alkali-free under optimised dyeing parameters. Experimental results reveal that RL-based reverse...

Reverse micellar dyeing of cotton woven fabrics with natural and biodegradable alkyl polyglucoside-based (APG-based) nonionic surfactant in decamethylcyclopentasiloxane (D5) non-aqueous medium with reactive dyes of different functional groups was investigated and compared with conventional aqueous water-based dyeing in terms of reflectance, color y...

Microplastics represent an emerging environmental problem worldwide, raising ecological and food safety concerns. Compared to microplastics, there is growing evidence of an even higher abundance of submicro- and nanoplastics in the environment, but a reliable monitoring method for detecting these smaller-sized plastics is lacking. Herein we present...

This work aims to examine the feasibility of using poly(ethylene glycol) (PEG)-based reverse micellar dyeing system for dyeing cotton fabric with the use of hot type trichloropyrimidine (TCP)-based reactive dyes and to evaluate the possibility of saving the dyeing energy used during the dyeing process. Experimental results show that fabrics dyed in...

Robust, hydrophobic woven cotton fabrics was obtained through the sol-gel dip coating of different nanoparticle architectures; silica and silica-ZnO. For water repellency, average values as high as ~148° and relatively low tilt angles for fibrous fabrics (~12°) were observed. In all cases, this enhanced functionality was achieved with the simultane...

In this study, we report the use of nanobubbles (NBs) as a simple and facile approach to effectively delay scaling in membrane distillation (MD) during the treatment of highly saline feed (100 g L⁻¹). Unlike conventional gas bubbling in MD for improving the hydrodynamic flow conditions in the feed channel, here we generated air NBs with an average...

Microplastics have become a significant environmental problem worldwide. Compared with microplastics, nanoplastics are apparently more abundant and harmful but their environmental processes are less well understood. The fate and ecological impacts of nanoplastics in aquatic environments are largely determined by their aggregation properties, which...

Current research on the use of carbon dots for various biological systems mainly focuses on the single carbon dots, while particles that contain multiple carbon dots have scarcely been investigated. Here, we assessed multiple carbon dots-crosslinked polyethyleneimine nanoparticles (CDs@PEI) for their in vivo biodistribution, clearance, biocompatibi...

The dyeing and color fixation properties of reactive dyes on cotton woven fabrics have been systematically studied using reverse micelle with biodegradable alkyl polyglucoside (APG)-based non-ionic surfactant as building blocks in cyclosiloxane-based solvent under one-bath one-step approach. Reactive dyes were solubilized in the interior region of...

Microplastics represent an emerging environmental issue that have been found almost everywhere including seafood, raising a great concern about the ecological and human health risks they pose. This study addressed the common technical challenges in the assessment of microplastics in seafood by developing an improved protocol based on Raman spectros...

Microplastics are prevalent in marine environments and seafood and thus can easily end up in human diets. This has raised serious concerns worldwide, particularly in Hong Kong where the seafood consumption per capita can be three times higher than the global average. This study focused on the green-lipped mussel Perna viridis, a popular seafood spe...

In contrast to traditional pigment colors, structural colors have developed a great potential in practical applications, thanks to their unique nonfading and color tunable properties; especially amorphous photonic structures with noniridescent structural colors have attracted considerable attention and their applications have expanded to more field...

The colour quality assessment of reverse micelle-based (in octane or nonane medium) and conventional water-based dyed wool knitted fabric has been investigated using computer colour matching (CCM) approach. Both water-based and non-aqueous based dyeing methods exhibited no chromatic shift from the reflectance curves and established good linearity i...

Structural-coloured poly(styrene-methyl methacrylate-acrylic acid) (Poly(St-MMA-AA)) deposited carbon fabrics (Poly(St-MMA-AA)/PCFs) with fascinating colours (salmon, chartreuse, springgreen, skyblue, mediumpurple) changing with the (Poly(St-MMA-AA) nanoparticle sizes can be facilely fabricated by the thermal-assisted gravity sedimentation method t...

The approach of using reverse micelle with nonionic surfactant (poly(ethylene glycol), PEG)) as building block has been employed to investigate dyeability of wool fabrics with reactive dyes in a one-bath non-aqueous solvent system. Three colours were used and they were encapsulated in the core of the PEG-based reverse micelle under optimised proces...

Effects of hardness and the pH value of water in a water pool on PEG-based nonionic surfactant dyeing of cotton fiber with reactive dyes in a heptane reverse micelle system were investigated in terms of the color yield, reflectance, CIE L*a*b* value, and unlevelness. Results reveal that the effect of the water-pool pH value on the color yield and r...

Reverse micellar dyeing of cotton fabrics with PEG-based non-ionic surfactant in heptane non-aqueous medium with the use of reactive dyes with different reactive groups was investigated. Single jersey knitted fabrics were used in this study. The experimental results reveal that samples dyed by both one-bath and two-bath heptane reverse micellar met...

Heavy-metal-free fluorescent nanoparticles with high photostability and low toxicity are highly desirable as imaging probes for biological applications. Here, a novel synthetic strategy to prepare ultrabright multi-carbon dot crosslinked PEI particles, namely CDs@PEI, through self-assembly of hydrophobically modified PEI and in situ generations of...

Computer color-matching (CCM) and the levelness of poly(ethylene glycol)-based reverse-micellar dyed wool fabrics in octane and nonane were investigated and compared with a conventional water-based dyeing system. Reflectance curves and calibration curves exhibited no chromatic change and maintained high linearity in both dyeing systems. The lineari...

Use of reactive dyes of red, blue and yellow colours for exhaustion dyeing of cotton conventional water-based dyeing method and PEG-based solvent-assisted reverse micelle dyeing method was investigated. Calibration curves of both dyeing approaches were established. The calibration results show that red dye can achieve higher absorbance value than y...

In this study, the inclusion of graphene oxide in silica photonic crystals was found to affect optical reflectance intensity and reflectance peak broadening. The quantitative relationship between weight percentage and the reflected light intensity and corresponding wavelength shift of light GO-decorated photonic crystals was studied, providing a us...

The effect of hydrophilic-lipophilic balance (HLB) of polyethylene glycol-based non-ionic surfactants of polyoxyethylene stearyl ether and polyoxyethylene tridecyl ether series of seven types on reverse micellar dyeing system of cotton was studied in non-aqueous heptane solvent medium. The relationships between HLB values of surfactants and reflect...

In this study, we explored the dyeing behavior of cotton with reactive dyes in poly(ethylene glycol)-based reverse micelle system in nonaqueous alkane medium of nonane (C9H20). Calibration of dyeing databases for both conventional aqueous-based dyeing method and nonaqueous nonane reverse micellar dyeing method was initially established, along with...

In this study, cotton fabrics were dyed with reactive dyes in conventional water-based and solvent-based reverse micellar dyeing systems. In solvent-based dyeing, heptane replaced water as the medium. Three commercially available reactive dyes with the primary colours of red, blue and yellow were used. Dyeing with different dye concentrations was c...

In this study, we investigated the computer colour matching (CCM) of cotton fabrics dyed with reactive dye using the octane-assisted reverse micellar approach. The aim of this study is to evaluate the colour quality and compare the accuracy between CCM forecasting and simulated dyeing produced by conventional water-based dyeing and octane-assisted...

In this chapter, an environment‐friendly approach in synthesizing Au and Au@Ag metal nanoparticles using a microgel is demonstrated. Poly(N‐isopropyl acrylamide)/polyethyleneimine microgel was used as a multifunctional template to reduce metal ions to metal nanoparticles, stabilize and immobilize these metal nanoparticles, and regulate their access...

The color matching and levelness of cotton fabrics dyed with reactive dye, in a non-aqueous environmentally-friendly medium of decamethylcyclopentasiloxane (D5), was investigated using the non-ionic surfactant reverse-micellar approach comprised of poly(ethylene glycol)-based surfactant. The calibration dyeing databases for both conventional water-...

The synthesis and property of dual stimuli-responsive amphiphilic particle consisting of a hydrophobic component, a pH-sensitive poly(ethyleneimine) (PEI) and a temperature-sensitive poly(N-isopropyl acrylamide) (PNIPAm) have been investigated. This novel type of multicomponent polymer (MCP) particles were prepared through a one-pot controlled semi...

A scalable synthesis of magnetic core-shell nanocomposite particles, acting as a novel class of magnetic resonance (MR) contrast agents, has been developed. Each nanocomposite particle consists of a biocompatible chitosan shell and a poly(methyl methacrylate) (PMMA) core where multiple aggregated γ-Fe2O3 nanoparticles are confined within the hydrop...

Herein we report a simple and green synthesis of smart Au and Ag@Au nanocomposite particles using poly(N-isopropylacrylamide)/polyethyleneimine (PNIPAm/PEI) core-shell microgels as dual reductant and templates in an aqueous system. The nanocomposite particles were synthesized through a spontaneous reduction of tetrachloroauric (III) acid to gold na...

The dyeability of cotton fabrics with reactive dye, in non-aqueous alkane medium of heptane and octane was investigated using a non-ionic surfactant reverse-micellar approach comprising of poly(ethylene glycol)-based surfactant. The reactive dye was satisfactorily encapsulated in the cavity of the reverse micelle under the optimised process paramet...

This data article describes the synthesis of temperature-sensitive and amine-rich microgel particle as a dual reductant and template to generate smart gold/polymer nanocomposite particle. TEM images illustrate the influence of reaction temperature on the formation and in-site encapsulation of gold nanoparticles using the temperature-sensitive micro...

Supplementary material

In this work, we demonstrated an easy route of producing bimetallic (Au@Ag) nanoparticles with the use of a PEI-based core-shell polymer particle as template. The polymer template serves not only as a nanoreactor to reduce metal ions into metal nanoparticles, but also as an immobilizer and stabilizer of these bimetallic nanoparticles. Since the tem...

Previous researches on solvent-dependent polymer systems mainly focus on amphiphilic invertible polymers (AIPs), which are capable of forming solvent-dependent micellar or inverse micellar assemblies. However, polymer particles that are invertible in response to solvent polarity are almost unexplored. In this paper, we report a new type of invertib...

In this work, we created an environmentally friendly route of producing gold nanoparticles with the use of a core-shell polymer particle template. The polymer template is a smart microgel that is responsive to both temperature and pH changes. The synthesis is composed of a two step reaction. First, is the preparation of the muti-responsive core-she...

Intriguing hierarchical structures, including nanotubular bundle, columnar, reticular plate-like and highly packed interwoven plate-like materials, have been created via self-assembly of amphiphilic core–shell nanotubes in water through varying the solution pHs between 3 and 13.

The mechanism for the formation of amphiphilic coreshell particles in water is elucidated via a kinetic study of semi-batch polymerization of methyl methacrylate (MMA) grafted from polyethylenimine (PEI) initiated with tert-butyl hydroperoxide in an emulsion polymerization. The monomer conversion, the polymerization kinetics, the particle size, the...

Polyphenols can oxidize in culture medium and produce artifacts in cell culture studies. However, the extent and mechanism of the oxidation of resveratrol, a polyphenol abundant in red wine, is unclear. We investigated the oxidation of resveratrol in vitro and the effects of various components of the culture medium on the degradation of resveratrol...

The aim of this research is to elucidate the mechanism for the formation of nanotubes from hollow particles of amphiphilic graft copolymers, such as poly(ethyleneimine)-graft-poly(methyl methacrylate) (PEI-g-PMMA), under non-equilibrium conditions. The study was performed at either 15 or 17 °C with fluid shear in a mixture of dichloromethane (DCM)-...

Nanodiamond films were deposited using different microwave plasma chemical vapor deposition schemes following several nucleation pretreatment methods. The nucleation efficiency and the films structure were investigated using scanning and transmission electron microscopy and Raman spectroscopy. C2 dimer growth (CH4 and H2 in 90% Ar) cannot nucleate...

A new multi-layered structure of heteroepitaxial (100) and (111) Ir grown on CaF2-buffered (001) and (111) Si wafers by UHV electron-beam evaporation was prepared for the deposition of diamond films. A two-step process of bias-enhanced nucleation and a subsequent growth by controlling the α growth parameter was performed to deposit (001) and (111)...

High quality epitaxial iridium films were grown on Si by using a fluoride as an intermediate layer. The epitaxial insulating layer acts as a diffusion barrier to impede film–substrate reactions at elevated temperatures and as a buffer layer for interface matching between lattice-mismatched metals and Si. Diamond deposited on the multilayer structur...

Staphylococcal nuclease mutants, E57G and E75G, were generated. A comparison of the kinetic parameters both for mutants and wild-type protein shows that the Michaelis constants (Km) were almost identical for the wild-type protein and E57G mutant. An approximately 30-fold decrease in Km compared with the wild-type protein was observed for the E75G m...

In this work, molecular dynamics simulations were used to examine the consequences of a variety of analogs of cecropin A on lipid bilayers. Analog sequences were constructed by replacing either the N- or C-terminal helix with the other helix in native or reverse sequence order, by making palindromic peptides based on both the N- and C-terminal heli...

The surface morphology, film quality, interface structure, growth rate and adhesion of diamond films prepared by hot filament chemical vapor deposition on commercial steel substrates with and without ion beam nitriding pretreatment were investigated by scanning electron microscopy, x-ray diffraction, scanning Auger spectroscopy, a Vickers microinde...

Diamond-like carbon coatings have been deposited by a pulse biased arc ion plating. In order to improve their adherence to metal substrate, two systems of graded transition layers, namely Ti/TiN/TiC and Ti/TiCN/TiC, have been applied. The structure and composition of the diamond-like carbon/transition composite coatings were studied by scanning ele...

Staphylococcal nuclease mutants, E57G and E75G, were generated. A comparison of the kinetic parameters both for mutants and wild-type protein shows that the Michaelis constants (Km) were almost identical for the wild-type protein and E57G mutant. An approximately 30-fold decrease in Km compared with the wild-type protein was observed for the E75G m...

Sorptions of four nonpolar, nonionic organic compounds (ben zene, toluene, ethylbenzene and o-xylene (BTEX)), and four polar, ionizable phenolic compounds (phenol, 2-chlorophenol, 2,4-dichlorophenol and 2,4,6-trichlorophenol) on dicetyldim ethylammonium (DCDMA) bentonite were determined in single-, binary-, ternary- and quaternary-solute systems. U...

In this study, the use of organically modified clay to remove the high-strength organic pollutants in leachate as well as reduce its liquid flow was investigated. Various physical and chemical factors that may affect the suitability of using the modified clay in removing and retarding the movement of contaminants have been examined. These factors i...

An organoclay complex was synthesized by placing quaternary ammonium compound on low-charge bentonite (CEC = 90 meq/100 g) through cation exchange reaction. This kind of compex was examined for its ability to adsorb non-polar hydrocarbons such as benzene, toluene. ethylbenzene and a-xylene (BETX). The organic cation used in this study was the trica...

An organoclay complex was synthesized by placing quaternary ammonium compound on low-charge bentonite (CEC = 90 meq/100 g) through cation exchange reaction. This kind of compex was examined for its ability to adsorb non-polar hydrocarbons such as benzene, toluene, ethylbenzene and o-xylene (BETX). The organic cation used in this study was the trica...

Pulsed UV lasers such as the 4th harmonic emission of Nd:YAG laser at 266 nm and ArF excimer laser at 193 nm have been used for surface modification of polymer surfaces, nano- structure fabrications on polymers and silicon substrates, and diamond deposition using photoablated polymer plumes. We report research carried out in our laboratory on these...

Quarter-micron linear and dot patterns were made on polyimide surface spin-coated onto silicon substrates with the Q-switched 4th-harmonic UV-pulses of Nd:YAG laser at 266 nm. Shallow polymer images were then transferred to silicon substrates by successive reactive ion etchings of SF6, O2 and SF6 C2ClF5 after filling in valleys of ripples with poly...

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 1994. Includes bibliographical references (leaves 126-129).