ZhaoTie Liu

Name: 刘昭铁; ZhaoTie Liu

Organization: Shaanxi Normal University

Department: Key Laboratory of Applied Surface and Colloid Chemistry, School of Chemistry and Chemical Engineering

Title: Professor

Chemicals
References

Immobilization of Cyclometalated Iridium Complex onto Multiwalled Carbon Nanotubes for Dehydrogenation of Indolines in Aqueous Solution

Co-reporter:Huan Liu, Jian-Gang Chen, Chao Wang, Zhao-Tie Liu, Yang Li, Zhong-Wen Liu, Jianliang Xiao, and Jian Lu

Industrial & Engineering Chemistry Research October 11, 2017 Volume 56(Issue 40) pp:11413-11413

Publication Date(Web):September 26, 2017

DOI:10.1021/acs.iecr.7b02804

Increasing concerns about the potentially negative impacts of chemical production on sustainable development of the overall environment have spurred numerous attempts to seek greener reaction mediums, recyclable catalysts, and high-efficiency procedures. Herein, a cyclometalated Ir complex with a pyrene tag was successfully immobilized onto multiwalled carbon nanotubes via π–π stacking interactions, through which an easily reusable Ir catalyst was constructed. The immobilization process was effectively monitored by using a fluorescence spectroscopy technique, and the immobilized Ir catalyst was well characterized and evaluated. It is found that the immobilized Ir catalyst exerts activity comparable to that of the corresponding homogeneous Ir catalyst for the dehydrogenation of indolines in an aqueous solution. More importantly, the catalyst could be recycled seven times without obvious loss of the Ir-active center and noticeable decrease in the yield of the targeted product. Additionally, the observed slight deactivation of the catalyst during the recycle is also discussed.

Construction of β-Trifluoromethyl Enol Ether via Base-Promoted C–O Coupling and Rearrangement of Hydrogen Atom

Co-reporter:Kun Dai, Kuan Wang, Yang Li, Jian-Gang Chen, Zhong-Wen Liu, Jian Lu, and Zhao-Tie Liu

The Journal of Organic Chemistry May 5, 2017 Volume 82(Issue 9) pp:4721-4721

Publication Date(Web):April 20, 2017

DOI:10.1021/acs.joc.7b00396

A novel, high-efficiency and high-selectivity construction of β-trifluoromethyl enol ether via base-induced/promoted C–O coupling of trifluoromethylated vinyl chloride and phenols is presented with a broad substrate scope. The reaction mechanism, especially the significantly high selectivity, was excavated and understood via DFT calculation and is well supported by the experimental observation.

Modeling and simulation of an improved ammonia-based desulfurization process for Claus tail gas treatment

Co-reporter:Yuyin Tang;Yang Gao;Dan Liu;Fenglian Zhang;Siqiu Qu;Zhengping Hao;Xin Zhang;Zhao-Tie Liu

RSC Advances (2011-Present) 2017 vol. 7(Issue 38) pp:23591-23599

Publication Date(Web):2017/04/27

DOI:10.1039/C7RA02343J

An improved ammonia-based desulfurization technology was proposed, in which the produced excess NH4HSO3 was concentrated by using the heat from the Claus tail gas and then SO2 was recovered by decomposing the concentrated NH4HSO3 in the Claus furnace. Furthermore, the process was modeled and simulated using the commercial software Aspen Plus. The characteristics of the ammonia-based desulfurization model were validated and compared with experimental results. Moreover, the water balance in the system was maintained, therefore, no extra water was required. Under the water balance condition, the SO2 removal performance in the system was predicted with various operating conditions. The model exhibited a reliable prediction of the desulfurization performance of the innovative process, which will be favorable for actual industrial application.

Selective oxidation of arylalkanes with N-Graphitic-Modified cobalt nanoparticles in water

Co-reporter:Dong-Huai Tu, Yang Li, Jiangwei Li, Yu-Jie Gu, Bo Wang, Zhao-Tie Liu, Zhong-Wen Liu, Jian Lu

Catalysis Communications 2017 Volume 97(Volume 97) pp:

Publication Date(Web):5 July 2017

DOI:10.1016/j.catcom.2017.04.038

•Co/phen@CB-800-L catalyst was synthesized.•The catalyst show high catalytic activity, selectivity in sp3 C-H oxidation.•Selective oxidation of alkylarenes were performed in H2O.•A broad scope of carbonyl compounds could be obtained in high yields.•The catalyst could be recycled up to six times without obvious loss in activity.N-Graphitic-Modified cobalt nanoparticles supported on carbon powder (Co/phen@CB-800-L) were prepared and found to be efficient catalysts for selective oxidation of arylalkanes to aromatic ketones with tert-butyl hydroperoxide (TBHP) in water. A broad scope of substrates have been investigated, the desired products were obtained with yields as high as 99% under the optimized condition in all cases. Remarkably, this carbon powder supported catalyst could be recovered easily, and showed high activity within six successive runs.

Nickel-catalyzed carbonylation of arylboronic acids with DMF as a CO source

Co-reporter:Yang Li;Dong-Huai Tu;Bo Wang;Ju-You Lu;Yao-Yu Wang;Zhao-Tie Liu;Zhong-Wen Liu;Jian Lu

Organic Chemistry Frontiers 2017 vol. 4(Issue 4) pp:569-572

Publication Date(Web):2017/03/28

DOI:10.1039/C7QO00001D

By using N,N-dimethylformamide (DMF) as a CO source, the cheap metal nickel-catalyzed carbonylation of arylboronic acids was demonstrated as an efficient and facile protocol for the synthesis of diaryl ketones. Results indicated that NiBr2·diglyme was the best pre-catalyst among the investigated transitional metal salts, and excellent yields were achieved via C–H and C–N bond cleavage.

Palladium catalyzed mono and difunctionalization of hexafluorobut-2-yne

Co-reporter:Bo Zhao, Yang Li, Dong-Huai Tu, Wei Zhang, Zhao-Tie Liu, Jian Lu

Tetrahedron Letters 2016 Volume 57(Issue 39) pp:4345-4347

Publication Date(Web):28 September 2016

DOI:10.1016/j.tetlet.2016.08.025

•One-pot mono and difunctionalization of hexafluorobut-2-yne is investigated respectively.•α,β-Trifluoromethylstyrenes and stilbenes can be obtained in high Z-stereoselectivity.•The reaction features simple manipulation.•The reaction could be carried out under mild conditions.•The reaction affords a facile access for a broad scope with good functional compatibility.The Pd(0) catalyzed one-pot mono and difunctionalization of hexafluorobut-2-yne is investigated. Styrenes and stilbenes can be obtained in high stereoselectivity by carbopalladation of phenylboronic acids and iodide benzenes. The reactions afford a facile access to a broad scope with good functional compatibility.

Vanadium Oxide Supported on Titanosilicates for the Oxidative Dehydrogenation of n-Butane

Co-reporter:Cun Wang, Jian-Gang Chen, Tian Xing, Zhao-Tie Liu, Zhong-Wen Liu, Jinqiang Jiang, and Jian Lu

Industrial & Engineering Chemistry Research 2015 Volume 54(Issue 14) pp:3602-3610

Publication Date(Web):March 26, 2015

DOI:10.1021/acs.iecr.5b00007

Vanadium-containing titanosilicates and V-containing SBA-15 catalysts for oxidative dehydrogenation (ODH) of n-butane at lower temperatures and with lower vanadia contents were contrastively studied. The catalysts were investigated by various techniques, namely, N2 adsorption–desorption, SAXS, TEM, FT-IR, XRD, XRF, H2-TPR, O2-TPD, and XPS, in relation to their performance for the ODH of n-butane. Results reveal that titanosilicate materials synthesized exhibit mesoporous structure, high BET specific surface area, and high total pore volume. H2-TPR, O2-TPD, and XPS results show that lattice oxygen exists in the surface of the V-containing titanosilicate catalysts and enhances the reducibility of vanadia-based catalysts with increasing TiO2 loadings. The V-containing titanosilicate catalysts exhibit much higher catalytic activity for the ODH of n-butane than that of V-containing SBA-15 at a significantly lower temperature of 460 °C, which indicates that lattice oxygen in the catalyst plays an important role in the activation of n-butane.

Highly Active and Stable Ni–SiO2 Prepared by a Complex-Decomposition Method for Pressurized Carbon Dioxide Reforming of Methane

Co-reporter:Hua-Ping Ren, Yong-Hong Song, Qing-Qing Hao, Zhong-Wen Liu, Wei Wang, Jian-Gang Chen, Jinqiang Jiang, Zhao-Tie Liu, Zhengping Hao, and Jian Lu

Industrial & Engineering Chemistry Research 2014 Volume 53(Issue 49) pp:19077-19086

Publication Date(Web):November 18, 2014

DOI:10.1021/ie502837d

A series of Ni–SiO2 catalysts was synthesized by the complex-decomposition method using different amino acids as complexing agents and fuels and nickel nitrate and tetraethoxysilane as precursors of Ni and SiO2, respectively. For comparison, ammonium hydroxide and acetic acid were also used as complexing agents and fuels. Characterization by XRD, TEM, and N2 adsorption–desorption at low temperature indicated that the structural and textural properties of the Ni–SiO2 catalysts were strongly dependent on the complexing agent used. The dispersion of metallic Ni was increased by optimizing the complexing agent used. As revealed from H2-TPR patterns, Ni–SiO2 exhibited significantly different interactions between Ni and SiO2, the extent of which was influenced by the complexing agent used. The Ni–SiO2 catalysts were comparatively evaluated for carbon dioxide reforming of methane (CDR) under the following conditions: CH4/CO2 = 1.0, T = 750 °C, GHSV = 53200 mL·g–1·h–1, and P = 1.0 atm. The results indicate that the Ni–SiO2 materials prepared with glycine, alanine, serine, threonine, valine, and proline exhibited much higher activity and stability for CDR under atmospheric conditions than those prepared with lysine, acetic acid, and ammonium hydroxide. Moreover, the Ni–SiO2 material prepared with glycine was also tested at elevated pressures of 5.0 and 10.0 atm. The effect of pressure on the CDR performance was investigated. Importantly, a highly active and stable Ni–SiO2 material for pressurized CDR was obtained by tailoring the structure of Ni–SiO2 and adjusting the interactions between Ni and SiO2 by selecting the complexing agent. Thus, the main factors determining catalyst activity and stability for CDR were clearly revealed.

One-Step, Continuous-Flow, Highly Catalytic Hydrogenation–Isomerization of Dicyclopentadiene to exo-Tetrahydrodicyclopentadiene over Ni-Supported Catalysts for the Production of High-Energy-Density Fuel

Co-reporter:Wei Wang, Jian-Gang Chen, Li-Ping Song, Zhao-Tie Liu, Zhong-Wen Liu, Jian Lu, Jianliang Xiao, and Zhengping Hao

Energy & Fuels 2013 Volume 27(Issue 11) pp:6339-6347

Publication Date(Web):August 13, 2013

DOI:10.1021/ef4010972

A one-step, continuous flow-phase, highly catalytic hydrogenation–isomerization of dicyclopentadiene (DCPD) directly into exo-tetrahydrodicyclopentadiene (exo-THDCPD) has been successfully performed over a fixed-bed reactor. This method is a greener and more cost-effective single-step route than the use of AlCl3 and noble metals (Pd, Pt, and Au) and, instead, employs a combination of Ni/γ-Al2O3 for hydrogenation and Ni/Hβ for isomerization. The bifunctional catalysts provided 100% DCPD conversion and 70% selectivity for exo-THDCPD and displayed a high stability without obvious deactivation over 200 h of testing. The synergistic effect of Ni hydrogenation activity and the isomerization activity of the supports is a key factor for the catalytic hydrogenation–isomerization of DCPD. A series of supports (ReY, USY, USReY, HY, HReY, Hβ, MCM-41, γ-Al2O3, SiO2, and NaY) were initially investigated as the Ni-supported catalysts. Surprisingly, we found that Hβ had a high activity for the isomerization of endo-THDCPD into exo-THDCPD. The integration of reactors was proposed to obtain the optimal hydrogenation and isomerization activities in a one-step, continuous flow-phase process. The physicochemical properties of the Ni-supported catalysts were studied using X-ray diffraction (XRD), O2 titration, thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), and NH3 temperature-programmed desorption (NH3-TPD). The influence of the reaction conditions, including temperature, pressure, reaction time, reduction time, liquid hourly space velocity (LHSV), Ni loading, catalyst weight ratio, calcination temperature of the catalysts, and solvents, was studied in detail.

Synthesis of TiO2/ramie fiber composite and its photocatalytic effect on the degradation of a dye in wastewater

Co-reporter:Jia-Jia Yang;Jian-Gang Chen;Li-Ping Song

Reaction Kinetics, Mechanisms and Catalysis 2013 Volume 110( Issue 2) pp:515-528

Publication Date(Web):2013 December

DOI:10.1007/s11144-013-0602-1

TiO2 was prepared by a hydrothermal method. It was chemically combined with carboxymethyl cellulose prepared from biodegradable ramie fiber to obtain the TiO2/ramie fiber composite. The TiO2/ramie fiber composites were characterized by an X-ray diffractometer, an environmental scanning electron microscope, and a Fourier-transform infrared spectra. The results indicate that TiO2 is chemically combined with ramie fiber, and it can be reused more than five times without obvious TiO2 loss. The photocatalytic performances of TiO2 and TiO2/ramie fiber composite used to degrade both a methyl orange (MO) anionic dye and a rhodamine B (RB) cationic dye solution indicate that the photocatalytic activities of TiO2 for the degradation of the above described solutions are greatly improved when the TiO2 is dispersed on ramie fiber. When 0.5 g of the TiO2/ramie fiber composite is added to a dye solution for 3 h, the degradation rates for the initial concentrations (20 mg/L of MO and 12 mg/L of RB) are greater than 90 %. The photocatalytic degradation of MO can be described as a zeroth order reaction.

Selective Hydrogenation of Cinnamaldehyde over Pt and Pd Supported on Multiwalled Carbon Nanotubes in a CO2-Expanded Alcoholic Medium

Co-reporter:Bao-Hui Zhao, Jian-Gang Chen, Xuan Liu, Zhong-Wen Liu, Zhengping Hao, Jianliang Xiao, and Zhao-Tie Liu

Industrial & Engineering Chemistry Research 2012 Volume 51(Issue 34) pp:11112-11121

Publication Date(Web):August 9, 2012

DOI:10.1021/ie301569q

Pt/MWCNT and Pd/MWCNT nanocatalysts were prepared via a liquid reduction method. The selective hydrogenation of cinnamaldehyde (CAL) was investigated over 5.0 wt.% Pt/MWCNT and 5.0 wt.% Pd/MWCNT catalysts in a CO2-expanded alcoholic medium at different reaction conditions. The hydrogenation selectivities over these two catalyst types were shown to be entirely different. It was found that the Pt/MWCNT catalysts are highly selective for C═O bonds, giving the unsaturated alcohol a selectivity for cinnamyl alcohol (COL) of 97.3% and a conversion rate for cinnamaldehyde of 99.3%. Conversely, the Pd/MWCNT catalyst is highly selective for C═C bonds, producing a saturated aldehyde with a selectivity for hydrocinnamaldehyde (HCAL) of 91.3% and a conversion rate for cinnamaldehyde of 98.6%. The small diameter of the Pt or Pd granules over the multiwalled carbon nanotubes (MWCNTs) leads to a high catalyst activity, and an increase of CO2 pressure results in a better hydrogenation performance for C═O bonds than that for C═C bonds.

Intermolecular-Interaction-Dominated Solvation Behaviors of Liquid Monomers and Polymers in Gaseous and Supercritical Carbon Dioxide

Co-reporter:Jian-Gang Chen, Xuan Liu, Zhong-Wen Liu, Dao-Dao Hu, Congjie Zhang, Dong Xue, Jianliang Xiao, and Zhao-Tie Liu

Macromolecules 2012 Volume 45(Issue 11) pp:4907-4919

Publication Date(Web):May 17, 2012

DOI:10.1021/ma300556z

The strong desire for the extensive application of supercritical carbon dioxide (scCO2) as an environmentally benign solvent in polymers synthesis and processing has spurred numerous attempts to discern and improve its solvability toward monomers as well as polymers. The detailed solvation processes along with the phase behaviors of a fluorinated liquid monomer (LM) of 2,2,2-trifluoroethyl methacrylate (TFEMA), as well as another 13 non-fluorinated LMs in gaseous and supercritical CO2, were respectively investigated by using a newly built high-pressure ATR-FTIR in situ monitoring system as CO2 pressure stepwise increased from 0 to 38.0 MPa. Interestingly, an unexpected vibrational absorption variation, especially a distinct blue-shift in the in situ FTIR spectra of the functional groups in each LM + CO2 binary system, was generally observed during the solvation process as CO2 pressure increased. A similar variation trend of the vibrational absorption of the C–F bond in the TFEMA + CO2 system was also obtained by ab initio calculation (MP2). We believe that the special evolution of the vibrational absorption is directly rooted in and dynamically induced by the variation of the intermolecular interactions in the LM + CO2 binary systems as the pressure and/or the temperature varied and is closely related to the solvation behaviors of the LM in CO2. Based on this cognition, the solvation mechanism of the LMs in gaseous and supercritical CO2 was systematically demonstrated by introducing the concepts of transition pressure (PT) as well as the resultant forces/interactions of σ(A–B) and σ(B–B). Poly(vinyl acetate) (PVAc), poly(hexafluoropropylene oxide) (PHFPO), and PTFEMA oligomers were prepared and characterized. The proposed mechanism was evaluated by investigating the solvation behaviors of the prepared oligomers and hexafluoropropylene trimer ((HFP)3) in CO2 and was successfully employed to expound the special CO2-philicity of the carbonyl compounds and the fluorinated organics (FOs).

The [Bmim]4W10O23 Catalyzed Oxidation of 3,4-Diaminofurazan to 3,4-Dinitrofurazan in Hydrogen Peroxide

Co-reporter:Hua-Ping Ren, Zhong-Wen Liu, Jian Lu, and Zhao-Tie Liu

Industrial & Engineering Chemistry Research 2011 Volume 50(Issue 11) pp:6615-6619

Publication Date(Web):April 27, 2011

DOI:10.1021/ie200009g

1-Methyl-3-butylimidazolium decatungstate ([C8H15N2]4W10O23, [Bmim]4W10O23) was prepared from 1-butyl-3-methylimidazolium bromide and sodium tungstate in hydrochloric acid solution. With the use of [Bmim]4W10O23 as the catalyst and 50% H2O2 as the oxidant, 3,4-dinitrofurazan (, DNF) was synthesized from 3,4-diaminofurazan (, DAF) in concentrated H2SO4. At a temperature of 35 °C, this process significantly increased the DNF yield from 39% to 58%, when compared with that with the conventional Na2WO4·2H2O catalyst under the same conditions. The effects of catalyst, reaction time, and temperature were investigated. A maximum DNF yield of 58% was obtained under optimal reaction conditions: 0.03 g of [Bmim]4W10O23, H2O2/H2SO4 molar ratio of 1.5:1, temperature and reaction time of 35 °C and 210 min, respectively.

Synthesis of Dimethyl Carbonate from Carbon Dioxide and Methanol over CexZr1-xO2 and [EMIM]Br/Ce0.5Zr0.5O2

Co-reporter:Zhi-Fang Zhang, Zhong-Wen Liu, Jian Lu, and Zhao-Tie Liu

Industrial & Engineering Chemistry Research 2011 Volume 50(Issue 4) pp:1981-1988

Publication Date(Web):January 19, 2011

DOI:10.1021/ie102017j

The solid solution series CexZr1-xO2 (x = 0.2, 0.3, 0.4, 0.5, 0.6, 0.8, 1.0) with a bimodal pore structure was prepared by the citric acid sol−gel method. Results from X-ray diffraction, Raman spectroscopy, scanning electron microscopy, mercury porosimetry, and N2 adsorption/desorption measurements indicated that the physical properties of the solid solutions were significantly affected by the Ce/Zr molar ratio and the calcination temperatures. These solid solutions can be used in the synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. Results indicated that the structure of the solid solutions and the Ce/Zr molar ratio in CexZr1-xO2 were the key factor in determining the catalytic activity for the synthesis of DMC. Higher catalytic performance was observed with a 1:1 Ce/Zr molar ratio at a calcination temperature of 1273 K. 1,1,1-Trimethoxymethane (TMM) was used to remove residual H2O in situ, and was found to increase the methanol conversion from 1.8 to 7.9% at 373 K under a pressure of 20 MPa after 24 h. The combination of the bimodal porous catalyst with an effective H2O removal agent gave a methanol conversion of 10.4% at 373 K, under 12 MPa after 34 h. The catalytic activity was almost doubled when the ionic liquid 1-ethyl-3-methylimidazolium bromide was loaded on Ce0.5Zr0.5O2, which may be a promising means for selective production of DMC from CO2 and CH3OH.

Cellulose acetate membrane synthesis from biomass of ramie

Co-reporter:Xiu-Shan Fan;Zhao-Tie Liu;Zhong-Wen Liu;Jian Lu

Journal of Applied Polymer Science 2010 Volume 117( Issue 1) pp:588-595

Publication Date(Web):

DOI:10.1002/app.31202

Abstract

A new route was developed for preparation of cellulose acetate (CA) membrane from ramie fiber, a sustainable biomass. Sulfuric acid catalyzed acetylation of ramie fiber was carried out in acetic anhydride. The optimum reaction conditions were determined as ramie fiber to acetic anhydride ratio 1 : 6 (w/w), temperature 353 K, and reaction time 0.5 h. To prepare CA membranes with improved properties, CA was modified with polyethylene glycol (PEG 600, M_W = 600 g/mol⁻¹) and tributyl citrate (TBC). The effects of CA content and additive concentrations given by a mixture design of experiments on CA membrane compaction, morphology, water flux, water content, and mechanical properties were studied. The thermal stability and hydrophobicity/hydrophilicity of membranes prepared with PEG 600 or TBC additives were also investigated. Addition of PEG 600 increased and addition of TBC decreased the thermal stability of CA membrane. The CA membranes prepared were used to separate dyes from their solutions. An inverse trend of the separation of solutions of Disperse Red S-R (DR) and Acid Scarlet 2G (AC) was observed for CA membranes modified with PEG 600 or TBC. The contact angle of CA membranes modified with PEG 600 or TBC decreased with increase in PEG 600 content, and increased with increase in TBC content. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Grafting of polystyrene and poly(p-chlorostyrene) from the surface of ramie fiber via RAFT polymerization

Co-reporter:Jie Yi;Jing Chen;Zhao-Tie Liu;Zhong-Wen Liu

Journal of Applied Polymer Science 2010 Volume 117( Issue 6) pp:3551-3557

Publication Date(Web):

DOI:10.1002/app.32261

Abstract

Reversible addition-fragmentation chain transfer (RAFT) radical polymerization was used for controlled grafting of styrene and p-chlorostyrene from the surface of ramie fiber. The hydroxyl groups in ramie fiber were first converted to thiocarbonylthio groups as the RAFT chain transfer agent then used to mediate the RAFT polymerization of styrene, and p-chlorostyrene in tetrahydrofuran using azobis (isobutyronitrile) as initiator at 60°C. The grafted copolymers were analyzed by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetry, and contact angle measurements. The results confirmed that grafting occurred on the surface of the ramie fiber, substantially increasing the water contact angle from 75.31° to 147° for polystyrene grafted ramie fiber (cell-PS) and 135° for poly(p-chlorostyrene) (cell-PSCl), and improving the hydrophobicity of the grafted fiber. The homopolymers formed in the polymerization were analyzed by size exclusion chromatography to estimate the molecular weights and polydispersity indices (PDIs) of chains grafted from the surface of the ramie fiber, as well as showed narrow chain length distributions with a PDI of 1.32–1.70. These materials possess potential applications in many advanced technologies. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Grafting modification of ramie fibers with poly(2,2,2-trifluoroethyl methacrylate) via reversible addition–fragmentation chain transfer (RAFT) polymerization in supercritical carbon dioxide

Co-reporter:Xiaoyan Liu, Jing Chen, Ping Sun, Zhong-Wen Liu, Zhao-Tie Liu

Reactive and Functional Polymers 2010 70(12) pp: 972-979

Publication Date(Web):December 2010

DOI:10.1016/j.reactfunctpolym.2010.10.007

Synthesis and catalytic behaviors of cobalt nanocrystals with special morphologies

Co-reporter:Zhao-Tie Liu, Xin Li, Zhong-Wen Liu, Jian Lu

Powder Technology 2009 Volume 189(Issue 3) pp:514-519

Publication Date(Web):13 February 2009

DOI:10.1016/j.powtec.2008.08.003

Cobalt nanocrystals with highly ordered snowflake-like, cauliflower-like, ball-like morphologies, and some less ordered shapes were prepared through the reduction of Co(NO3)2 by hydrazine hydrate in the solution of methanol, ethanol, ethylene glycol, and 1,2-propanediol. Based on the characterization results of X-ray powder diffraction and scanning electron microscope, crystal and morphologic structures of cobalt particles were correlated with the reaction conditions of temperature, Co(NO3)2 concentration, and the alcohols used. By changing temperature and/or Co(NO3)2 concentration, pure hexagonal close-packed (hcp) cobalt or a mixture of hcp and face-centered cubic (fcc) cobalt was obtained. The catalytic performance of as-prepared cobalt nanocrystals for the thermal decomposition of ammonium perchlorate (AP) was evaluated by differential scanning calorimetry. The decomposition temperature of AP was significantly decreased, and the apparent decomposition heat was over doubled when 2 wt.% cobalt was added into AP. Among the samples tested, snowflake-like cobalt showed the best performance in the aspect of decreasing the decomposition temperature of AP while the ball-like cobalt exhibited the highest apparent decomposition heat.Cobalt nanocrystals with highly ordered snowflake-like, cauliflower-like, and ball-like morphologies were prepared by reducing Co(NO3)2 with hydrazine hydrate in the solution of different alcohols. The cobalt nanocrystals showed high catalytic performance towards the decomposition of ammonium perchlorate, in which the decomposition temperature significantly decreased, and the decomposition heat obviously increased.

Chemically Modified Chicken Feather as Sorbent for Removing Toxic Chromium(VI) Ions

Co-reporter:Ping Sun, Zhao-Tie Liu and Zhong-Wen Liu

Industrial & Engineering Chemistry Research 2009 Volume 48(Issue 14) pp:6882-6889

Publication Date(Web):June 18, 2009

DOI:10.1021/ie900106h

To improve the sorption capacity of Cr(VI) ions, chicken feathers (CFs) were chemically treated by several methods: (1) To clarify the changes in the structure and morphology of CFs, CFs were treated with aqueous NaOH solutions of varying concentrations. The results suggest that reactions occur on the surface rather than in the interior of the CFs and that keratin fragments exfoliate from the CF surface layer by layer and then dissolve in aqueous solution. (2) Keratin fragments could be rejoined to the CF surface by cross-linking with epichlorohydrin (Epi) through a series of ring-opening, recyclization, and ring-opening reactions of Epi in aqueous NaOH solution, and Epi-modified CF (EpiCF) was obtained. (3) CFs were functionalized with ethylenediamine (EA) in aqueous NaOH solution by cross-linking with Epi (EAEpiCF). The structure and properties of chemically treated CFs were investigated by FT-IR spectroscopy, XRD, SEM, elemental analysis, and water contact-angle measurements. CFs treated with NaOH were found to be similar in structure and properties to each other and exhibited a relatively low sorption capacity for removal of Cr(VI) ions from water, but a higher capacity than raw CFs. EpiCF exhibited an excellent capacity for adsorbing relatively low concentrations (10 ppm) of Cr(VI) ions but a low sorption capacity for Cu(II) ions in water. EAEpiCF was found to be hydrophilic and to exhibit 90% efficiency for removing Cr(VI) ions in the concentration range of 10−80 ppm but to have a low sorption capacity for Cu(II) in water. Equilibrium sorption isotherms for the raw and chemically treated CFs fit the Freundlich and Dubinin−Radushkevich (D−R) isotherm models; however, the Langmuir model was not able to describe the sorption behavior. The values of the free sorption energy (E) were calculated. The E values of NaOH-treated CFs were found to be similar to each other and much larger than that of raw CFs for the sorption of Cr(VI), and the sorption processes were found to be physical. The process of EpiCF adsorbing Cr(VI) ions from water is chemisorption, and that for Cu(II) ions is physisorption. The free sorption energy of EAEpiCF sorption of Cr(VI) ions was close to 8 kJ·mol−1 (7.274 kJ·mol−1), so that chemical interactions might exist between EAEpiCF and Cr(VI), whereas for Cu(II), the sorption process is physical adsorption.

Cellulose Triacetate Optical Film Preparation from Ramie Fiber

Co-reporter:Xiushan Fan, Zhong-Wen Liu, Jian Lu and Zhao-Tie Liu

Industrial & Engineering Chemistry Research 2009 Volume 48(Issue 13) pp:6212-6215

Publication Date(Web):May 27, 2009

DOI:10.1021/ie801703x

A new route for the preparation of cellulose triacetate (CTA) optical films from the biomass of ramie fiber has been found with environmental benefits. CTA with a degree of substitution (DS) of 2.81−2.92 was prepared by the reaction of acetic anhydride with ramie fiber catalyzed by sulfuric acid in acetic acid solution at 55 °C. The CTA film was prepared by casting the solution of CTA dissolving in dichloromethane on the culture disk via spreading the solution through a syringe. The structure and properties of CTA and its film were investigated by Fourier transform infrared (FT-IR), ultraviolet (UV), X-ray diffraction (XRD), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and titration. It was found that the CTA films prepared from ramie fiber shows a high transparency of 89% and excellent mechanical properties with stress measurements of 31.04−47.80 MPa and strain of 3.99−5.22%. The CTA films prepared from ramie fiber are suitable as protective films for the liquid crystal displays (LCD).

Modification of ramie fiber with an amine-containing polymer via atom transfer radical polymerization

Co-reporter:Zhao-Tie Liu;Chang'an Sun;Zhong-Wen Liu;Jian Lu

Journal of Applied Polymer Science 2009 Volume 113( Issue 6) pp:3612-3618

Publication Date(Web):

DOI:10.1002/app.30351

Abstract

The covalent bonding of tertiary amine 2-(dimethylamino)ethyl methacrylate to ramie fiber via atom transfer radical polymerization was obtained with a brominated initiator and the catalyst CuCl/1,10-phenanthroline. The results reveal that poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) was successfully immobilized on the surface of the ramie fiber in a controlled polymerization. After the grafting with PDMAEMA, the crystal structure of cellulose I in the ramie fiber was still preserved, and the lateral size of the microfibrils, calculated on the basis of plane 002, was slightly increased. As a demonstration of possible applications, the modified fiber was dyed with CI Reactive Red 2. The dye uptake, which almost linearly increased with increasing molecular weight of PDMAEMA attached on the ramie fiber, was raised to be over 15 times that of the raw fiber. The reason was that the reactivity between the tertiary amines in PDMAEMA and the dichlorotriazinyl group in the dye molecules was much higher than that between the hydroxyl groups in the ramie fiber and the reactive groups in the dye molecules. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Solubilities of l-Proline in Subcritical HFC-134a and Supercritical CO2 Fluids

Co-reporter:Ling Liu, Zhen Li, Zhong-Wen Liu and Zhao-Tie Liu

Journal of Chemical & Engineering Data 2009 Volume 54(Issue 9) pp:2780-2784

Publication Date(Web):April 22, 2009

DOI:10.1021/je801009z

A static method coupled with gravimetric analysis was used to measure the solubility of l-proline in subcritical 1,1,1,2-tetrafluoroethane (HFC-134a) and supercritical CO2 (scCO2). The solubility of l-proline is much higher in HFC-134a fluid than in scCO2. The solubilities of l-proline in HFC-134a and scCO2 are affected by temperature and pressure. The solubilities increase with increasing temperature and pressure for both scCO2 and HFC-134a solvents. The densities of scCO2 and subcritical HFC-134a were calculated using the Peng−Robinson (P-R) equation. Experimentally determined density data were used to assess the accuracy of the P-R equation.

Grafting from ramie fiber with poly(MMA) or poly(MA) via reversible addition-fragmentation chain transfer polymerization

Co-reporter:Jing Chen;Jie Yi;Ping Sun;Zhao-Tie Liu;Zhong-Wen Liu

Cellulose 2009 Volume 16( Issue 6) pp:

Publication Date(Web):2009 December

DOI:10.1007/s10570-009-9343-8

Reversible addition-fragmentation chain transfer (RAFT) polymerization was utilized to control the grafting of methyl methacrylate (MMA) and methyl acrylate (MA) from natural ramie fibers substrate. The hydroxyl groups of ramie fibers were first converted to 2-dithiobenzoyl isobutyrate as a RAFT chain transfer agent (CTA), which was further grafted with MMA or MA mediated by the RAFT polymerization in a presence of 2-(ethoxycarbonyl)prop-2-yl dithiobenzoate as a free chain transfer agent. Hydrophobic poly(MMA) or poly(MA) modified ramie fibers with contact angles greater than 130° were obtained. The modified ramie fibers were analyzed by gravimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, thermogravimetry and contact angle measurements. The results indicate that the polymer chains had indeed been grafted from the surface of the ramie fibers with an average 33% of the hydroxyl groups in the raw ramie fiber substituted by 2-bromoisobutyryl bromide and an average grafting ratio of 25% poly(MMA) or poly(MA) related to ramie fiber. The homopolymers formed in the copolymerization were also analyzed to estimate molecular weights and polydispersity indices of grafting chains from the surface of ramie fibers by size exclusion chromatography, which showed narrow polydispersity with the PDIs to be <1.32. This study provides a novel and feasible approach to the preparation of functional composite materials for utilizing the abundant natural ramie fiber cellulose resource.

Acetylation of β-cyclodextrin in ionic liquid green solvent

Co-reporter:Zhao-Tie Liu;Li-Hong Shen;Zhong-Wen Liu;Jian Lu

Journal of Materials Science 2009 Volume 44( Issue 7) pp:1813-1820

Publication Date(Web):2009 April

DOI:10.1007/s10853-008-3238-1

The ionic liquid (IL), 1-butyl-3-methylimidzolium bromide ([C4mim]Br), synthesized under supercritical CO2, was developed as a green solvent for the dissolution, regeneration and acetylation of β-cyclodextrin (β-CD). The dissolution of β-CD in [C4mim]Br of 25 wt% could be reached at 25 °C. The acetylation of β-CD was carried out under acetic anhydride in [C4mim]Br in the absence of catalyst. β-CD acetates with different degrees of substitution of 0.07–1.14 were obtained directly under the homogeneous reaction conditions. The reaction medium of IL applied can be easily recycled and reused after the synthesis of β-CD acetate. The effects of reaction time, temperature, and acetic anhydride/AGU on the acetylation of β-CD were investigated. The acetylated β-CD samples were characterized by NMR, FT-IR, and X-ray diffraction (XRD) spectroscopy. It is the first time that we have demonstrated that ILs can be used as an environmentally friendly solvent for the acetylation of β-CD, which will open a new route to acetylation of β-CD under green solvent without catalyst.

Study on the performance of ramie fiber modified with ethylenediamine

Co-reporter:Zhao-Tie Liu, Yani Yang, Lili Zhang, Ping Sun, Zhong-Wen Liu, Jian Lu, Heping Xiong, Yuande Peng, Shouwei Tang

Carbohydrate Polymers 2008 Volume 71(Issue 1) pp:18-25

Publication Date(Web):5 January 2008

DOI:10.1016/j.carbpol.2007.05.008

The chelate molecule, ethylenediamine, was incorporated onto the surface of ramie fiber via sequential reactions of the hydroxyl groups on ramie fiber with epichlorohydrin followed by the chelating agent. The performance of the modified material (CelNH) was characterized by Fourier transform infrared spectroscopy (FI-IR), X-ray diffraction (XRD), scanning electron micrographs (SEM), thermogravimetry analysis (TGA), UV–Vis, and elemental analysis. Results show that the excellent characteristics of the raw fiber were still remained after modification although the crystallinity of the modified fiber decreased. The modification parameters were optimized as the concentration of ethylenediamine of 0.75 mol/l, the temperature of 50 °C, and the reaction time of 5 h. Meanwhile, the dye of C.I. reactive red 2 was used to study the dyeability of the raw and the modified fibers. The color strength and the dye uptake of the modified fiber increased obviously with an increase in the nitrogen contents in CelNH. The color strength and the dye uptake of the modified fiber can be controlled by changing the extent of surface modification of raw ramie fiber.

Adjustable wettability of methyl methacrylate modified ramie fiber

Co-reporter:Zhao-Tie Liu;Chang'an Sun;Zhong-Wen Liu;Jian Lu

Journal of Applied Polymer Science 2008 Volume 109( Issue 5) pp:2888-2894

Publication Date(Web):

DOI:10.1002/app.28259

Abstract

The surface hydrophobicity/hydrophilicity of ramie fiber was regulated through the atom transfer radical polymerization of methyl methacrylate from initiators immobilized on the fiber. The optimal reaction conditions for preparing the macroinitiated ramie fiber were determined to be a temperature of 60°C and a reaction time of 24 h. The grafted copolymers were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, energy-dispersive analysis of X-rays, gel permeation chromatography, and thermogravimetric analysis. The results indicate that poly (methyl methacrylate) was covalently bonded onto the surface of the ramie fiber, and the polymerization of methyl methacrylate was a living/controlled process under the investigated conditions. The results of the contact angle measurements indicate that the wettability of the ramie fiber could be widely regulated by control of the grafted ratios of poly(methyl methacrylate) from 26 to 33 wt %. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Benzylated modification and dyeing of ramie fiber in supercritical carbon dioxide

Co-reporter:Zhao-Tie Liu;Zhifeng Sun;Zhong-Wen Liu;Jian Lu;Heping Xiong

Journal of Applied Polymer Science 2008 Volume 107( Issue 3) pp:1872-1878

Publication Date(Web):

DOI:10.1002/app.27220

Abstract

The effects of pretreatment conditions, including the addition of a phase-transfer catalyst, on the benzylation of ramie fiber were investigated in this study. Raw and benzylated ramie fibers were dyed in supercritical carbon dioxide, and the color strength (K/S) of the ramie fiber was measured by ultraviolet–visible spectroscopy. An obviously improved dyeing capability of the benzylated ramie fiber, that is, a better level-dyeing property and a higher K/S, was achieved. Moreover, the color strength of the ramie fiber, indexed as the value of K/S, increased significantly with the degree of substitution of the benzylated ramie fiber. The raw and modified ramie fibers were characterized with Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

New Process for Synthesizing Fluorinated Polymers in Supercritical Carbon Dioxide

Co-reporter:Zhao-Tie Liu, Jian-Gang Chen, Zhong-Wen Liu and Jian Lu

Macromolecules 2008 Volume 41(Issue 19) pp:6987-6992

Publication Date(Web):September 18, 2008

DOI:10.1021/ma800193v

The typical polymerization process in supercritical fluids (SCFs) was improved through modifying the reaction system and designing and using sampling tubes. The efficacy of the newly developed procedure was demonstrated by the free radical homopolymerization of 2,2,2-trifluoroethyl methacrylate (TFEMA) and coplymerization of TFEMA and N-vinylpyrrolidone (NVP) in supercritical carbon dioxide (scCO2). Results indicate that the newly developed procedure has the characteristics of minimum loss of reactants and polymerization starting at the desired temperature and pressure. Furthermore, the polymerization process can be well tracked by analyzing the reaction mixtures online sampled from the reactor at certain reaction times by FT-IR, 1H NMR, and GPC. The reaction time and the product properties can be optimized based on the tracking results. For the first time, block copolymers by free radical polymerization in scCO2 was successfully synthesized by sequential addition of TFEMA and methyl methacrylate (MMA) into the reactor at different reaction stages. The synthesized polymers were characterized by FT-IR, 1H NMR, 13C NMR, GPC, TGA, and DSC, respectively. It was proved that the losing of monomer, pollution to the environment, and distribution of the molecular weight of the synthesized polymers decreased while the yield of product, the reproducibility, and the controllability of polymerization increased after improvement of the polymerization process.

Preparation and characterization of highly dispersed nanocrystalline rutile powders

Co-reporter:Zhao-Tie Liu, Shushan Yao, Ping Sun, Liping Song, Jian Lu, Heping Xiong, Yuande Peng, Shouwei Tang

Materials Letters 2007 Volume 61(Issue 13) pp:2798-2803

Publication Date(Web):May 2007

DOI:10.1016/j.matlet.2006.10.033

A highly dispersed nanocrystalline rutile powder (NRP) having ultrafine and narrow-distributed diameters was successfully prepared via an improved conventional liquid one-step method by introducing dioctyl sulfosuccinate sodium salt (AOT) surfactant in the peptization reaction anaphase. The average grain size of the product is 10–20 nm. The effects of the titanium tetrabutoxide (Ti(OBu)4) to ethanol volumetric ratio, the precipitation temperature, the peptization temperature and the presence of dioctyl sulfosuccinate sodium salt (AOT) on the preparation of NRP were studied. A new procedure for synthesizing NRP is proposed, and the optimum conditions for preparing NRP were obtained. The TEM, XRD, SEM and FT-IR results were also investigated in this work.

Study on the cationic modification and dyeing of ramie fiber

Co-reporter:Zhao-Tie Liu;Yani Yang;Lili Zhang;Zhong-Wen Liu;Heping Xiong

Cellulose 2007 Volume 14( Issue 4) pp:337-345

Publication Date(Web):2007 August

DOI:10.1007/s10570-007-9117-0

A modification procedure for ramie fiber using 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC) as a cationic agent and NaOH as a catalyst was developed in this paper. The morphological and structural transformations of the fiber induced by modification were determined by XRD (XRD), differential scanning calorimetry (DSC), and thermogravimetry analysis (TGA). XRD results show that the crystal structure of the modified fiber was still preserved although its crystallinity was decreased, which was confirmed from the TGA results. The mechanisms for the modification and dyeing of ramie fiber were analyzed, and the optimum modification conditions were determined to be the CHPTAC concentration of 30 g L−1, the NaOH concentration of 15 g L−1, the reaction temperature of 50 °C, and the reaction time of 60 min. The raw and the modified fibers were dyed with C.I. reactive red 2. The K/S values for the cationic modified fiber increased to be three times as high as the unmodified fiber. The dye uptakes increased greatly with an increase in the nitrogen contents up to 0.4% on the modified fibers.

Phase behavior of novel fluorinated surfactants in supercritical carbon dioxide

Co-reporter:Zhao-Tie Liu, Jin Wu, Ling Liu, Liping Song, Ziwei Gao, Wensheng Dong and Jian Lu

Green Chemistry 2006 vol. 8(Issue 11) pp:978-983

Publication Date(Web):16 Aug 2006

DOI:10.1039/B602105K

A series of novel fluorinated analogues of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) surfactants, the sodium salt of bis(3,3,4,4,5,5,6,6,6-nonafluoro-1-hexanol) sulfosuccinate (CF3(CF2)3CH2CH2OOCCH2CH(SO3Na)COOCH2CH2(CF2)3CF3, di-HCF5), the sodium salt of bis(2,2,3,4,4,4-hexafluoro-1-butanol) sulfosuccinate (CF3CFHCF2CH2OOCCH2CH(SO3Na)COOCH2CF2CFHCF3, di-HCF3), the sodium salt of bis(2,2,3,3- tetrafluoro-1-propanol) sulfosuccinate (HCF2CF2CH2OOCCH2CH(SO3Na)COOCH2CF2CF2H, di-HCF2), and the sodium salt of bis(2,2,3,3,3-pentafluoro-1-propanol) sulfosuccinate (CF3CF2CH2OOCCH2CH(SO3Na)COOCH2CF2CF3, di-CF2), were synthesized and characterized by 1H NMR, 13C NMR, 19F NMR and FT-IR spectroscopy, melting point, and elemental analysis. The pressure–temperature phase behavior for water-in-CO2 microemulsions stabilized by the four surfactants was tested and the P–T diagrams were determined. In the phase behavior experiments, pressures up to 35 MPa, temperatures up to 65 °C, and water-to-surfactant molar ratios (Wo) from 10 to 30 were tested. The cloud-point pressure in microemulsions stabilized by the four fluorinated surfactants increased with increasing temperature, and at a fixed temperature, the cloud-point pressure increased with increasing Wo. However, the cloud-point pressure was only slightly affected by an increase in the concentration of surfactant at a settled Wo. The phase behavior for water-in-CO2 microemulsions at different Cd(NO3)2 concentrations in the aqueous phase with the surfactant di-HCF5 was also determined, which is useful for the formation of CdS nanoparticles in our future studies.

Sutures modified by silver-loaded montmorillonite with antibacterial properties

Co-reporter:Gao-Fei Cao, Yan Sun, Jian-Gang Chen, Li-Ping Song, Jin-Qiang Jiang, Zhao-Tie Liu, Zhong-Wen Liu

Applied Clay Science (May 2014) Volumes 93–94() pp:102-106

Publication Date(Web):May 2014

DOI:10.1016/j.clay.2014.03.007

A green route to prepare cellulose acetate particle from ramie fiber

Co-reporter:Zhao-Tie Liu, Xiushan Fan, Jin Wu, Lili Zhang, Liping Song, Ziwei Gao, Wensheng Dong, Heping Xiong, Yuande Peng, Shouwei Tang

Reactive and Functional Polymers (February 2007) Volume 67(Issue 2) pp:104-112

Publication Date(Web):February 2007

DOI:10.1016/j.reactfunctpolym.2006.10.001

Selective hydrogenation of cinnamaldehyde over Pt-supported multi-walled carbon nanotubes: Insights into the tube-size effects

Co-reporter:Zhao-Tie Liu, Chun-Xia Wang, Zhong-Wen Liu, Jian Lu