Yonglin Lei

Nanotechnology, Materials Chemistry, Photochemistry

11.43

Publications

  • Yonglin Lei, Hong Lei, Jichuan Huo
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    ABSTRACT: A novel hindered amine modified aromatic polyamide dendrimer/polystyrene-grafted-TiO2 hybrid photocatalyst (HADPG-TiO2) was synthesized. And a new kind of controllable photodegradable polystyrene (PS) composite was prepared by embedding the HADPG-TiO2 into the commercial polystyrene. Solid-phase photocatalytic degradation of the PS-HADPG-TiO2 composite was carried out in ambient air at room temperature under solar light irradiation. The HADPG-TiO2 was characterized by FT-IR and scanning electron microscopy (SEM), X-ray diffraction (XRD) and UV-Vis diffuse reflectance spectroscopy, in comparison with reference materials (plain TiO2). The properties of PS-HADPG-TiO2 films were compared with those of the pure PS films and PS-TiO2 films by methods such as weight loss measurement, SEM and tensile properties measurement. The results showed that the HADPG-TiO2 had a better dispersion in PS polymer and could absorb the visible light. The PS-HADPG-TiO2 films had better tensile properties, compared with the pure PS films and PS-TiO2 films. Moreover, the as-prepared PS-HADPG-TiO2 films showed more excellent photostability under solar light irradiation for 0-250h and higher photodegradable efficiency under the solar light irradiation for 600 h than the pure PS films and PS-TiO2 films. The photocatalytic degradation mechanism of the films was briefly discussed. The novel fabrication method of composite polymer provides a valuable way for developing highly efficient and controllable photodegradable plastics.
    Polymer Degradation and Stability 04/2015; 118. DOI:10.1016/j.polymdegradstab.2015.04.005 · 2.63 Impact Factor
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    ABSTRACT: A new bis(benzimidazolyl) monomer containing biphenyl group, 4,4′-bis(2-benzimidazolyl) diphenyl, was successfully synthesized from 4,4′-biphenyldicarboxylic acid and 1,2-phenylenddiamine. The corresponding biphenyl-containing poly(N-arylenebenzimidazole)s were prepared using C-N coupling reaction that removed the N-H sites from the novel bis(benzimidazolyl) derivative with activated aromatic difluorides in sulfolane. The reaction was carried out at 210°C in the presence of anhydrous potassium carbonate. All resulting polymers showed essentially amorphous patterns. This was consistent with the calculated results. Differential scanning calorimetry and thermogravimetric measurements showed that the polymers had high glass transition temperatures (>253°C) and good thermal stability with high decomposition temperatures (>457°C). These novel polymers also showed easy solubility.
    Polymer Science Series B 11/2014; 56(6):799-806. DOI:10.1134/S1560090414770012 · 0.63 Impact Factor
  • Yonglin Lei, Qiuru Wang, Jichuan Huo
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    ABSTRACT: In order to provide an effective damp-proof protection of inorganic radome materials, we have developed a new method to fabricate superhydrophobic coatings, which uses Polyvinylidene fluoride (PVDF) and SiO2 micron particles to seal porous surfaces of inorganic radome materials and hydrophobized silica colloid to form superhydrophobic surface. The coatings were characterized by moisture absorption rate analysis, dielectric constant and loss tangent measurements, static contact angle and sliding angle measurements, SEM, AFM, TG, FTIR and wear tests. All of the characterizations revealed the coatings had a micro nano hierarchical structure with a static contact angle of 157.5 degrees and sliding angle of 9 degrees, and possessed high thermal stability and excellent mechanical durability. These coatings have potential uses in engineering applications of inorganic porous materials requiring damp-proof protection and high durability.
    Ceramics International 08/2014; 40(7):10907-10914. DOI:10.1016/j.ceramint.2014.03.087 · 2.09 Impact Factor
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    Yonglin Lei, Chi Zhang, Hong Lei, Jichuan Huo
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    ABSTRACT: A novel aromatic polyamide dendrimer-TiO2 hybrid photocatalyst functionalized with spirolactam-based molecular switch (RG-TiO2) was synthesized. The materials were characterized by FT-IR and scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and UV-vis diffuse reflectance spectroscopy, in comparison with reference materials (plain TiO2). The photocatalytic activity and photostability of RG-TiO2 were investigated based on the degradation of phenol under visible light irradiation. The results showed that the RG-TiO2 hybrid photocatalyst enhanced photocatalytic efficiency of photodegradation of phenol compared with the as-prepared plain TiO2 under visible light irradiation. More significantly, when the RG-TiO2 was acidified to pH 3, the RG-TiO2 was readily transformed from spirolactam form (OFF) to the ring-opened amide form (ON). And the photocatalytic stability of ring-opened RG-TiO2 (switch off form) was much lower than that of ring-closed RG-TiO2 (switch on form). The novel fabrication method of the TiO2 photocatalyst provides a valuable way for developing highly efficient and controllable photocatalysts by molecular switch.
    Journal of Colloid and Interface Science 06/2013; 406. DOI:10.1016/j.jcis.2013.05.063 · 3.55 Impact Factor
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    Yonglin Lei, Yuanqiang Su, Jichuan Huo
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    ABSTRACT: Two novel poly(amidoamine) (PAMAM) dendrimers, comprising rhodamine B unit in the core and 1-phenyl-3-methyl-5-pyrazolone unit at the periphery, have been synthesized and characterized. Both dendrimers displayed high selectivity and sensitivity towards Cr3+ ion. As considering the potential of being applied as fluorescent sensors for Cr3+ ion, we studied the complexes formed between the dendrimers and Cr3+ ion. Different PAMAM dendrimers had different recognition mechanism towards Cr3+ ion. For dendrimer G2, the recognition of Cr3+ was mainly due to the ring-opening of spirolactam. However, it significantly depended on the simultaneous effect of ring-opening of spirolactam and photoinduced electron transfer (PET) in the case of dendrimer G3.Highlights► First synthesize two novel PAMAM simultaneously containing rhodamine and pyrazolone. ► Novel dendrimer show high selectivity and sensitivity towards Cr3+. ► Recognition Cr3+ of dendrimer G2 is dominantly due to the ring-opening mechanism. ► Sensing Cr3+ of dendrimer G3 is dependent on simultaneous mechanisms of ring-opening and PET.
    Journal of Luminescence 12/2011; 131(12):2521-2527. DOI:10.1016/j.jlumin.2011.06.011 · 2.37 Impact Factor
  • Yonglin Lei, Yuanqiang Su, Jichuan Huo
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    ABSTRACT: A novel poly (amidoamine) (PAMAM) dendrimer, comprising rhodamine B unit in the core and 1-phenyl-3-methyl-5-pyrazolone unit at the periphery, has been synthesized and characterized. The dendrimer shows dramatic increase in its fluorescence intensity in the presence of proton and metal cations, especially in the presence of Cr(3+). The complex formed by dendrimer and Cr(3+) in ethanol solution has also been studied, considering the potential application for Cr(3+) fluorescent sensor. The influence of the unique chemical structure and resulted photoinduced electron transfer, as well as spirolactam ring-opening on the photophysical properties of the product has been investigated.
    Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 08/2011; 83(1):149-54. DOI:10.1016/j.saa.2011.08.006 · 2.13 Impact Factor

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