Co-reporter:Xuemin Du, Ngai-Yu Lei, Hiu-Man Chiu, Xuewu Ge, Zhicheng Zhang and Michael Hon-Wah Lam
Journal of Materials Chemistry A 2013 vol. 1(Issue 11) pp:1535-1540
Publication Date(Web):07 Jan 2013
DOI:10.1039/C2TB00236A
Microspherical photonic colloidal crystalline beads that are responsive to media ionic strength of cationic electrolytes have been developed for in vivo imaging of the morphology and concentration gradient of cationic electrolytes along the gastrointestinal (GI) tract of live Japanese medaka (Oryzias latipes). These responsive photonic beads were assembled from core–shell nano-sized particles with polystyrene-co-polyacrylic acid (PS-co-PAA) cores and poly(hydroxyethyl methacrylate-co-p-styrene sulfonate) (PHEMA-co-PSS) hydrogel shells. The three-dimensional orderly packing of these nano-sized core–shell particles gave rise to the photonic properties of the resultant colloidal crystalline array of microspheres. The cationic electrolyte-induced volume phase transition of the sulfonate-laden hydrogel shells of the nano-sized particles altered the lattice spacing among those particles and brought about the photonic responses of the colloidal crystalline beads. Unambiguous changes in the diffraction colour of the colloidal crystalline beads were observable under ordinary ambient light in solution media of increasing concentration of sodium chloride up to 500 mM. These photonic colloidal crystalline beads were found to possess enough structural integrity for in vivo imaging of the GI tract of live Japanese medaka. With the use of a conventional optical microscope, the gradient in the ionic strength of cationic electrolytes along the GI tract of live Japanese medaka larvae was readily revealed, with a lower electrolyte concentration in the mid-intestine (<50 mM) compared to that of the posterior-intestine (≥50 mM). Our results demonstrated the potential of stimuli-responsive photonic materials in bio-imaging applications.
Co-reporter:Xuemin Du, Ngai-Yu Lei, Peng Hu, Zhang Lei, Daniel Hock-Chun Ong, Xuewu Ge, Zhicheng Zhang, Michael Hon-Wah Lam
Analytica Chimica Acta 2013 Volume 787() pp:193-202
Publication Date(Web):17 July 2013
DOI:10.1016/j.aca.2013.05.022
•Fabrication of pH-responsive photonic colloidal crystalline microspheres.•Specific photonic band-gap responses occurred in the pH range of 4–5.•Remarkably low in vivo toxicity to Japanese medaka (Oryzia latipes).•In vivo imaging of the morphology and pH along GI tract of Japanese medaka.•Demonstrates bio-imaging potentials of stimuli-responsive photonic materials.Colloidal crystalline microspheres with photonic band-gap properties responsive to media pH have been developed for in vivo imaging purposes. These colloidal crystalline microspheres were constructed from monodispersed core–shell nano-size particles with poly(styrene-co-acrylic acid) (PS-co-PAA) cores and poly(acrylic acid-co-N-isopropylacrylamide) (PAA-co-PNIPAM) hydrogel shells cross-linked by N,N′-methylenebisacrylamide. A significant shift in the photonic band-gap properties of these colloidal crystalline microspheres was observed in the pH range of 4–5. This was caused by the discontinuous volume phase transition of the hydrogel coating, due to the protonation/deprotonation of its acrylic acid moieties, on the core–shell nano-sized particles within the microspheres. The in vivo imaging capability of these pH-responsive photonic microspheres was demonstrated on a test organism – Japanese medaka, Oryzia latipes – in which the morphology and change in pH along their gastrointestinal (GI) tracts were revealed under an ordinary optical microscope. This work illustrates the potential of stimuli-responsive photonic band-gap materials in tissue-/organ-level in vivo bio-imaging.
Co-reporter:Shufen Wang;Huarong Liu;Wei Zhang
Colloid and Polymer Science 2010 Volume 288( Issue 9) pp:1031-1039
Publication Date(Web):2010 June
DOI:10.1007/s00396-010-2236-4
This paper is devoted to the preparation of manganese dioxide/polystyrene nanocomposite foams via a novel and facile one-step method using high internal phase emulsion as templates. Scanning electron microscopy (SEM), Fourier transform infrared spectrometer (FT-IR), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analyses (TGA) techniques were used to characterize the resulting composites. SEM measurements revealed the porous network structure, the average pore diameters ranged from 3.8 to 30.4 μm. The presence of manganese dioxide was identified by XPS pattern, XRD, pattern and FT-IR spectra of the resulting composites. The TGA thermograms showed that the maximum content of manganese dioxide in the nanocomposite foams reached about 15.5%. The applications of the nanocomposite in the oxidative degradation of methylene blue exhibited good catalytic activity in the presence of H2O2 as an oxidant.
Co-reporter:Zhen Qian, Zhicheng Zhang, Linyong Song and Huarong Liu
Journal of Materials Chemistry A 2009 vol. 19(Issue 9) pp:1297-1304
Publication Date(Web):22 Jan 2009
DOI:10.1039/B810808K
A new strategy was developed to prepare raspberry-like particles by introducing poly(acrylic acid) (PAA)-functionalized polystyrene (PS) particles into hydrolysis reaction of tetraethoxysilane (TEOS). The monodisperse PAA-functionalized PS particles were used as cores and nanosized silica particles were then assembled on the surface of PS particles to construct raspberry-like particles during the hydrolysis process. With the increase of PAA content from 11% to 20% (wt) at the surface of latexes, the diameter of the silica particles assembled at the surface of cores decreased from 124 nm to 36 nm. The structure, morphology and constitution of the PAA-functionalized PS particles and the raspberry-like particles were characterized by Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). In addition, the particulate films were constructed by assembling these raspberry-like particles on glass substrates. After surface modification with dodecyltrichlorosilane, superhydrophobic surfaces can be obtained and the contact angle of water on the dual-sized structured surface can be adjusted by the scale ratio of the micro/nano surface structure of raspberry-like particles.
Co-reporter:Shengnan Song, Wei Zhang, Zhongqing Hu, Zhicheng Zhang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2009 Volume 348(1–3) pp:1-8
Publication Date(Web):20 September 2009
DOI:10.1016/j.colsurfa.2009.07.019
Monodisperse carboxyl-functionalized polystyrene particles with range of 600–2100 nm were synthesized by two-stage radiation-induced dispersion polymerization of styrene in ethanol/water media using poly (vinylpyrrolidone) (PVP) as the stabilizer and itaconic acid (IA) as a functional comonomer. The resulting carboxylated polystyrene (PS) particles had a narrower size distribution compared with those obtained by one-stage dispersion polymerization. In the two-stage method, the presence of additional IA in the second reaction may help to prevent secondary nucleation and to promote the formation of monodisperse particles. The effects of concentration of IA, PVP and solvent polarity on the particle size and size distribution were discussed in detail. The characterizations (particle size and size distribution, locus of the carboxyl groups) of carboxylated PS microspheres were carried out by the scanning electron microscope (SEM), particle diameter measure and analysis system and conductometric titration. In order to examine the surface carboxylation of PS particles, P (St-co-IA)/Co composite microspheres were prepared by repetitious interface deoxidized reactions. The composite microspheres were characterized by transmission electron microscope (TEM), SEM, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD).
Co-reporter:Wei Zhang, Jiangying Li, XueMin Du, Zhicheng Zhang
Materials Research Bulletin 2009 44(11) pp: 2072-2080
Publication Date(Web):
DOI:10.1016/j.materresbull.2009.07.009
Co-reporter:Zhen Qian, Zhicheng Zhang, Yun Chen
Journal of Colloid and Interface Science 2008 Volume 327(Issue 2) pp:354-361
Publication Date(Web):15 November 2008
DOI:10.1016/j.jcis.2008.08.024
A novel and facile approach to the preparation of paramagnetic magnetite/polystyrene nanocomposite microspheres by 60Co γ-ray radiation-induced miniemulsion polymerization is reported. First, we modified the magnetite nanoparticles (MPs) with a Y-shaped surfactant: 12-hexanoyloxy-9-octadecenoic acid (HOA). Nanocomposite microspheres consisting of polystyrene–iron oxide nanoparticles then were prepared by the radiation-induced miniemulsion polymerization of styrene in the presence of HOA-modified MPs using HOA as stabilizer. The final products were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The effects of the dose rate, the amounts of added hexadecane (HD) and MPs, and the morphology of the final products were studied. We have also studied the polymerization kinetics to prove the miniemulsion polymerization mechanism of the nanocomposite microspheres.Preparation of high-magnetite-content MPs/polystyrene nanocomposite particles with a narrow PDI by 60Co γ-ray radiation-induced miniemulsion polymerization and its mechanism are illuminated.
Co-reporter:Jun Chen, Xinbo Wang, Zhicheng Zhang
Materials Letters 2008 Volume 62(4–5) pp:787-790
Publication Date(Web):29 February 2008
DOI:10.1016/j.matlet.2007.06.061
A facile and efficient method is described for the in situ synthesis of mesoporous CdS semiconductor nanoparticles by gamma ray irradiation in oil-in-water microemulsion. The prepared mesoporous CdS nanoparticles were characterized by high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), scanning electron microscope (SEM), X-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) gas sorptometry. The mesoporous structure of CdS nanoparticles is well-characterized by TEM and XRD. The obtained mesoporous CdS nanoparticles possessed a high surface area of 82.6 m2/g and a number of pores with the pore size distribution centered at about 9.4 nm. A possible growth mechanism for the mesoporous structure has been proposed.
Co-reporter:Mei Tao, Zhongqing Hu, Zhicheng Zhang
Materials Letters 2008 Volume 62(4–5) pp:597-599
Publication Date(Web):29 February 2008
DOI:10.1016/j.matlet.2007.06.011
Poly(styrene-alt-maleic anhydride) latexes were first obtained by emulsion polymerization induced by gamma ray. FTIR, 1H-NMR and potentiometric titration methods were used to identify the alternating structure of the product. Then the transmission electron microscopy (TEM) method was used to observe the morphology of the micelles. As the pH of the latex increases from 3 to 7, the shape of aggregates changes from short-shuttle to long-rod. When the pH increases to 10, the rod-like aggregates are not found. The result indicates that the linearity of chains occurring at pH 7 induces the formation of the specific morphology with the cooperation of anionic/nonionic mixed surfactants templates.
Co-reporter:Zhen Qian;Haiming Li;Huarong Liu ;Zhongqin Hu
Journal of Polymer Science Part A: Polymer Chemistry 2008 Volume 46( Issue 1) pp:228-237
Publication Date(Web):
DOI:10.1002/pola.22375
Abstract
We have successfully prepared biocompatible and biodegradable hollow microspheres using carboxyl-functionalized polystyrene particles as core template and the chitosan cross-linked with glutaraldehyde as the shell. The monodisperse carboxyl-functionalized polystyrene particles were made by emulsifier-free emulsion polymerization. The structure, morphology, and constitution of the carboxyl-functionalized polystyrene particles were characterized by FTIR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The structure, morphology, and formation process of the hollow cross-linked chitosan microspheres were characterized by FTIR, SEM, and TEM. The results revealed that the latex particles were removed by exposed to solvent and the microspheres exhibited the hollow structure. This work confirmed that the hollow microspheres were accomplished by fabricating on the basis of chemical cross-linking on the surface of the carboxyl-functionalized polystyrene particles and then removing off the cores of particles. Moreover, with the increase of carboxyl-functionalization degree at the surface of latexes and the increase of cross-linking period, the thicker and firmer monodisperse hollow microspheres were obtained. In addition, a water-soluble drug, salicylic acid, encapsulated in the microcapsules slowly released at pH 1.2. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 228–237, 2008
Co-reporter:Jun Nie;Mingxuan Zou;Qingchun Zhao
Journal of Applied Polymer Science 2007 Volume 103(Issue 3) pp:1406-1411
Publication Date(Web):8 NOV 2006
DOI:10.1002/app.24843
Gamma ray-induced seeded emulsion polymerization of methyl methacrylate and butyl acrylate was carried out in the presence of polymerizable polysiloxane seed latex, which was obtained by the ring-opening copolymerization of octamethyl cyclotetrasiloxane (D4) and tetramethyl tetravinyl cyclotetrasiloxane(VD4) catalyzed by dodecylbenzene sulfonic acid (DBSA). After the first seeded polymerization, 3-methacryloxylpropyltrimethoxylsilane (MPS) was added for the second seeded polymerization. The conversion–time curve showed that the first seeded polymerization rate was accelerated much by the polysiloxane seed latex. The final composite lattices also showed good storage stability, mechanical stability, and high electrolyte resistance ability. The morphology of the composite latex particles was found to be a quite uniform fine structure by transmission electron microscopy (TEM). The graft of polyacrylates onto polysiloxane and hydrolysis of MPS were confirmed by Fourier transform infrared (FT-IR) spectroscopy. The mechanical performance, water absorption ratio, surface properties, and transparency of the latex films were also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1406–1411, 2007
Co-reporter:X.Y. Wang, W.J. Liu, X.B. Wang, Z.C. Zhang, H.R. Liu
Materials Letters 2007 Volume 61(23–24) pp:4478-4481
Publication Date(Web):September 2007
DOI:10.1016/j.matlet.2007.02.025
Polymethylacrylic acid (PMA)/Polystyrene (PS) composite particles with different morphologies were prepared using reactive Y-shape surfactant AOA by controlling the content of surfactant and weight ratio of styrene/kerosene. High weight percentage of surfactant and weight ratio of styrene/kerosene lead to the structure of one large PS particle in which many PMA micro-gels were embedded, while low weight percentage of surfactant and weight ratio of styrene/kerosene led to composite particles with core/shell morphology. The formation mechanism of the particles with different morphologies was discussed in this article.
Co-reporter:Zhongqing Hu, Mei Tao, Zhicheng Zhang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2007 Volume 302(1–3) pp:307-311
Publication Date(Web):20 July 2007
DOI:10.1016/j.colsurfa.2007.02.049
The radiation-induced dispersion polymerization of styrene in an ethanol–water mixture has been investigated using a novel “gradient” copolymer consisting of styrene–maleic anhydride (St–MA) and maleic anhydride–N-vinyl pyrrolidone (MA–NVP) complexes as a stabilizer. The influence of parameters such as the molar mass, the concentration and the molecular architecture of the “gradient” copolymers on the colloidal dispersion has been studied. Mono-dispersed polystyrene particles could be obtained in the range of 400–700 nm.
Co-reporter:Wei Zhang, Mei Tao, Zhongqing Hu, Zhicheng Zhang
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2007 Volume 305(1–3) pp:58-65
Publication Date(Web):15 September 2007
DOI:10.1016/j.colsurfa.2007.04.041
Nearly monodisperse poly(2-(diethylamino) ethyl methacrylate) (PDEA) microgels were prepared directly by radiation-induced dispersion polymerization in water/ethanol media using poly(vinylpyrrolidone) (PVP) as the stabilizer at room temperature under certain circumstance (appropriate ethanol/water ratio and monomer dosage), which afforded novel pH-responsive behavior with range of 600–2500 nm. This method takes the advantages of radiation-induction (no chemical initiator, temperature independent, uniform initiation with a high efficiency and so on) that may result in the formation of uniform polymer particles. PVP acted as not only a physical stabilizer, but also as a macromonomer to form the grafted copolymer, which was confirmed by the Fourier transform infrared (FT-IR) and proton nuclear magnetic resonance (1H NMR) and was important for the stabilization of microgels. The characterization (morphology, size and distribution, and swelling/deswelling kinetics) of PDEA microgels were carried out by the scanning electron microscope (SEM), dynamic light scattering (DLS) and turbidity studies.
Co-reporter:Nana Cao;Xinbo Wang;Lingyong Song;Zhi Cheng Zhang
Journal of Polymer Science Part A: Polymer Chemistry 2007 Volume 45(Issue 24) pp:5800-5810
Publication Date(Web):30 OCT 2007
DOI:10.1002/pola.22330
A polymerizable cationic quaternary ammonium surfactant (CQAS) based on 2-(dimethylamino)ethyl methacrylate (DMAEMA) was successfully synthesized via quaternization reaction. The product was characterized by FTIR and 1H NMR spectroscopy, and its critical micelle concentration (CMC) was obtained by surface tension measurement. The surfmer acted well as comonomer and surfactant to stabilize monomer droplets during miniemulsion polymerization. To identify whether this system undergoes miniemulsion nucleation mechanism, surface tension, particle size, and Ndroplet/Nparticle of the system were also measured. The effect of concentration and counter-ion of the surfmer, and pH value of the system were systematically investigated by kinetic analysis and dynamic light scattering (DLS). The resulting nanopore microspheres were observed by transmission electron micrograph (TEM) and field emission scanning electron micrograph (FESEM) and showed the nanopore morphology with reasonable stability. Another cationic surfactant cetyltrimethylammonium bromide (CTAB) was used for comparative studies. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5800–5810, 2007
Co-reporter:Xinbo Wang, Changqi Xu, Zhicheng Zhang
Materials Letters 2006 Volume 60(Issue 3) pp:345-348
Publication Date(Web):February 2006
DOI:10.1016/j.matlet.2005.08.048
A one-step, solid-state reaction route was developed to synthesize copper sulfide (CuS) nanorods via grinding Cu(NO3)2·3H2O and Na2S·9H2O in existence of ethylenediamine tetraacetic acid disodium salt (Na2EDTA·2H2O) at ambient temperature. The as-prepared CuS nanorods have diameters of 5∼7 nm, lengths up to 40∼70 nm. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to characterize the obtained product. A possible reaction mechanism was discussed at the end of this article.
Co-reporter:Mingxuan Zou;Shijie Wang;Fangzhi Huang;Xuewu Ge
Polymer International 2006 Volume 55(Issue 3) pp:
Publication Date(Web):3 JAN 2006
DOI:10.1002/pi.1953
Composite polystyrene and polymethylsilsesquioxane (PS-PMSSQ) latices were prepared by hydrolysis and polycondensation of triethoxylmethylsilane (TEOMS) in the presence of PS seed latices, obtained by gamma ray induced polymerization. Morphology of the composite latex particles was observed by transmission electronic microscopy and their size distribution was measured by dynamic laser light scattering. It was found that if 1 wt% silicon-containing surfactant (SCS) and 0.4 wt% dodecylbenzene sulphonic acid (DBSA) were both used, core–shell/PS-PMSSQ latex particles could be prepared at 30 °C. The core–shell structure was further characterized by X-ray photoelectron spectrometry. With 0.5 wt% SCS or 0.2 wt% DBSA, the capsulation was incomplete. At 0 and 90 °C, the PMSSQ phase penetrated into the seed particles. No core–shell structure was observed when DBSA was replaced by hydrochloric acid or SCS was replaced by poly(ethylene glycol) monooctylphenyl ether. Copyright © 2006 Society of Chemical Industry
Co-reporter:Weiwei Wang;Mozhen Wang;Zhenqi Chang
Journal of Applied Polymer Science 2006 Volume 102(Issue 6) pp:5587-5594
Publication Date(Web):28 SEP 2006
DOI:10.1002/app.24897
Acrylic acid carboxylated acrylic rubber (ACM) and itaconic acid carboxylated acrylic rubber were prepared by 60Co-γ-ray-induced emulsion copolymerization. The polymers were characterized using FTIR and 13C NMR spectroscopies. The acid value was determined with nonaqueous titration method. The molecular weight and the polydispersity index of the polymers were measured using gel permeation chromatography. The influence of the cure-site (carboxyl) on the vulcanization and mechanical properties of the ACM was researched by means of rheometric study, gel fraction analysis, mechanical property tests, and dynamic mechanical thermal analysis. The results show that the crosslink density of polymers increases with amounts of the carboxyl cure-site. The itaconic acid carboxylated ACM has better cure characteristics and mechanical properties than the acrylic acid carboxylated ACM has. In addition, the comparison of ACM prepared by 60Co-γ-ray-induced polymerization with ACM prepared by chemical-initiator-induced polymerization has been investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5587–5594, 2006
Co-reporter:Changqi Xu, Zhicheng Zhang, Qiang Ye
Materials Letters 2004 Volume 58(Issue 11) pp:1671-1676
Publication Date(Web):April 2004
DOI:10.1016/j.matlet.2003.11.005
A facile disproportion reaction method is successfully developed to synthesize metal sulfide (cadmium sulfide, CdS; silver sulfide, Ag2S; and mercury sulfide, HgS) under room temperature and ambient pressure. Various morphology of metal sulfide is obtained under role of PVP as an assisted-reagent for crystal growth. X-ray diffraction (XRD), transmission electron microscope (TEM), and ultraviolet–visible (UV–Vis) spectrum are used to characterize the obtained product. The disproportion reaction mechanism happened in this experiment is suggested in the end of this paper.
Co-reporter:Qiu Dai;Feng Wang;Jie Liu;Qiu Dai;Feng Wang;Jie Liu
Journal of Applied Polymer Science 2003 Volume 88(Issue 12) pp:2732-2736
Publication Date(Web):26 MAR 2003
DOI:10.1002/app.11890
In this study, polydimethylsiloxane (PDMS)/polyacrylate composite polymer latex was synthesized via polymerization of the acrylate monomer in the presence of vinyl-containing PDMS seeded latex. The polymerization was initiated by 60Co γ-ray irradiation. The morphology of the PDMS/polyacrylate composite polymer latex was a core–shell structure with PDMS as the core and polyacrylate as the shell. There was an interpenetration layer between the PDMS core and the polyacrylate shell. The composition of the vinyl-containing PDMS and the PDMS/polyacrylate composite latex were investigated with NMR and Fourier transform infrared spectroscopy, respectively. The effect of irradiation dose on the seeded emulsion polymerization conversion is discussed. Finally, the mechanical properties of latex film, such as water-absorption ratio, tensile strength, pendulum hardness, and heat-decomposed temperature, were tested. The results showed that the mechanical properties of the PDMS/polyacrylate film were remarkably improved when compared to the polyacrylate film. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2732–2736, 2003
Co-reporter:Changqi Xu, Yonghong Ni, Zhicheng Zhang, Xuewu Ge, Qiang Ye
Materials Letters 2003 Volume 57(Issue 20) pp:3070-3076
Publication Date(Web):June 2003
DOI:10.1016/S0167-577X(02)01438-6
Co-reporter:Xuemin Du, Ngai-Yu Lei, Hiu-Man Chiu, Xuewu Ge, Zhicheng Zhang and Michael Hon-Wah Lam
Journal of Materials Chemistry A 2013 - vol. 1(Issue 11) pp:NaN1540-1540
Publication Date(Web):2013/01/07
DOI:10.1039/C2TB00236A
Microspherical photonic colloidal crystalline beads that are responsive to media ionic strength of cationic electrolytes have been developed for in vivo imaging of the morphology and concentration gradient of cationic electrolytes along the gastrointestinal (GI) tract of live Japanese medaka (Oryzias latipes). These responsive photonic beads were assembled from core–shell nano-sized particles with polystyrene-co-polyacrylic acid (PS-co-PAA) cores and poly(hydroxyethyl methacrylate-co-p-styrene sulfonate) (PHEMA-co-PSS) hydrogel shells. The three-dimensional orderly packing of these nano-sized core–shell particles gave rise to the photonic properties of the resultant colloidal crystalline array of microspheres. The cationic electrolyte-induced volume phase transition of the sulfonate-laden hydrogel shells of the nano-sized particles altered the lattice spacing among those particles and brought about the photonic responses of the colloidal crystalline beads. Unambiguous changes in the diffraction colour of the colloidal crystalline beads were observable under ordinary ambient light in solution media of increasing concentration of sodium chloride up to 500 mM. These photonic colloidal crystalline beads were found to possess enough structural integrity for in vivo imaging of the GI tract of live Japanese medaka. With the use of a conventional optical microscope, the gradient in the ionic strength of cationic electrolytes along the GI tract of live Japanese medaka larvae was readily revealed, with a lower electrolyte concentration in the mid-intestine (<50 mM) compared to that of the posterior-intestine (≥50 mM). Our results demonstrated the potential of stimuli-responsive photonic materials in bio-imaging applications.
Co-reporter:Zhen Qian, Zhicheng Zhang, Linyong Song and Huarong Liu
Journal of Materials Chemistry A 2009 - vol. 19(Issue 9) pp:NaN1304-1304
Publication Date(Web):2009/01/22
DOI:10.1039/B810808K
A new strategy was developed to prepare raspberry-like particles by introducing poly(acrylic acid) (PAA)-functionalized polystyrene (PS) particles into hydrolysis reaction of tetraethoxysilane (TEOS). The monodisperse PAA-functionalized PS particles were used as cores and nanosized silica particles were then assembled on the surface of PS particles to construct raspberry-like particles during the hydrolysis process. With the increase of PAA content from 11% to 20% (wt) at the surface of latexes, the diameter of the silica particles assembled at the surface of cores decreased from 124 nm to 36 nm. The structure, morphology and constitution of the PAA-functionalized PS particles and the raspberry-like particles were characterized by Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). In addition, the particulate films were constructed by assembling these raspberry-like particles on glass substrates. After surface modification with dodecyltrichlorosilane, superhydrophobic surfaces can be obtained and the contact angle of water on the dual-sized structured surface can be adjusted by the scale ratio of the micro/nano surface structure of raspberry-like particles.
