Aiqin Hou  Yunxia Zhou 《Journal of Dispersion Science and Technology》2013,34(9):1254-1259

The organic/inorganic hybrid nanomaterials containing silica nanoparticles are synthesized by sol-gel crosslinking process. The tetraethoxysilane (TEOS) and γ-aminopropyltriethoxylsilane as coupling agents are used as a precursor. The 2,4,6-tri [(2-epihydrin-3-bimethyl-ammonium)propyl]-1,3,5-triazine chloride (Tri-EBAC) as crosslinking agent is used to form covalent bonds among the inorganic nanoparticles. The chemical and morphological structures of the organic/inorganic hybrid are characterized with FTIR spectra, ²⁹Si-NMR, x-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and atomic force microscope (AFM). The results show that the organic/inorganic hybrid forms covalent bond between the inorganic nanoparticle and Tri-EBAC. The network organic/inorganic hybrid can form good film with even nanometer particles. The network organic/inorganic hybrids nanomaterial not only exhibits the thermal properties of inorganic compounds, but also exhibits the thermal properties of organic polymer.  相似文献   

    

Bao-Feng Hou  Yong Huang 《Journal of Dispersion Science and Technology》2013,34(9):1264-1273

The mechanism of spontaneous imbibition of water by sandstone cores and the relationship between reservoir wettability and imbibition recovery were studied by investigating factors influencing the spontaneous imbibition of different surfactants by oil-wet sandstone cores. Ultimate oil recovery of cores using the cationic surfactant CTAB was higher than that of the cores using the nonionic surfactant TX-100 and the anionic surfactant POE (1) at the same concentration. For CTAB and TX-100, the ultimate oil recovery by spontaneous imbibition increased with increase in surfactant concentration. In regard to imbibition recovery, TX-100 and POE(1) at high temperatures were superior to those at low temperatures. Ultimate oil recovery of the high-permeability core was higher than that of the low-permeability core at room temperature. According to changes in the driving force during the imbibition process, the imbibition curve could be divided into three regions: (1) mainly capillary force, (2) both capillary and gravity forces, and (3) mainly gravity force. The stronger the hydrophilicity of the rock surface, the higher the spontaneous imbibition recovery.  相似文献   

    

Xiaogang Yang  Bin Li  Haizeng Wang  Baorong Hou 《Journal of Dispersion Science and Technology》2013,34(5):672-676

The inhibition effect of cetyl trimethyl ammonium bromide (CTAB) on the corrosion of mild steel in 1.0 mol L^?1 hydrochloric acid (HCl) has been studied at different temperatures (25–60°C) by weight loss and potentiodynamic polarization methods. The results reveal that CTAB behaves as an effective inhibitor in 1.0 mol L^?1 HCl, and the inhibition efficiency increases with the inhibitor concentration. Polarization curves show that CTAB is a mixed-type inhibitor in hydrochloric acid. The results obtained from weight loss and polarizations are in good agreement. The effect of immersion time on corrosion inhibition has also been examined and is discussed. The adsorption of inhibitor on mild steel surface obeys the Langmuir adsorption isotherm equation. Thermodynamic parameters have been obtained by adsorption theory. The inhibition effect is satisfactorily explained by the parameters.  相似文献   

    

Kongliang Xie  Aiqin Hou  Yaqi Shi 《Journal of Dispersion Science and Technology》2013,34(3):321-326

A series of functional polyorganosiloxanes containing fluorocarbon side chain and amino groups had been synthesized by ring-opening polymerization. The raw materials used were Octamethyl cyclotetrasiloxane (D₄), dodecafluoroheptyl-propyl-trimethoxylsilane (502) and γ-aminopropyltriethoxylsilane (550), respectively. FTIR, ¹H-NMR, ¹³C-NMR, and ¹⁹F-NMR were used to characterize the copolymer structures. The surface properties of the functional polyorganosiloxanes emulsions were discussed. The results showed that the functional polyorganosiloxanes containing fluorocarbon and amino side chains had low surface tension and excellent water repellency.  相似文献   

    

Guangbin Yang  Zhanming Zhang  Shengmao Zhang  Laigui Yu  Pingyu Zhang  Yanchao Hou 《Surface and interface analysis : SIA》2013,45(11-12):1695-1701

Cu nanoparticles surface‐capped by alkanethiols were synthesized using ligand exchange method in a two‐phase system. The effects of synthetic conditions, including the pH value of CuSO₄ solution, the ratio of cetyltrimethyl ammonium bromide to CuSO₄, and reaction temperature, on the size and shape of as‐synthesized Cu nanoparticles were investigated. As‐synthesized Cu nanoparticles surface‐capped by alkanethiols with different chain lengths (C_xS‐Cu) were characterized by means of X‐ray diffraction, transmission electron microscopy, Fourier transform infrared spectrometry, and ultraviolet–visible light spectrometry. The tribological behavior of C_xS‐Cu as an additive in liquid paraffin was evaluated with a four‐ball machine. Results indicate that cetyltrimethyl ammonium bromide plays an important role in controlling the dispersion of Cu nanoparticles before adding modifier octanethiol into the reaction solution. C_xS‐Cu nanoparticles as additive in liquid paraffin possess excellent antiwear and friction‐reduction performance because of the deposition of nano‐Cu with low melting point on worn steel surface leading to the formation of a self‐repairing protective layer thereon. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

    

Ying Liu  Ying‐Hui Yu  Yi‐Fu Liu  Guang‐Feng Hou  Xiao‐Dan Wang  Bo Wen  Jin‐Sheng Gao 《无机化学与普通化学杂志》2013,639(1):193-196

The cage‐like complex, Ag₄L₄(NO₃)₄ ( 1 ) [L = 1, 4‐bis(pyridine‐2‐ylmethoxy)benzene] was synthesized by the reaction of the flexible bidentate ligand and silver nitrate. It was characterized by elemental analysis, IR spectroscopy, TG, and single‐crystal X‐ray analysis. Complex 1 is reported as the first cage‐like cluster constructed by four nitrate anions bridging two [2+2] macrocycles. A blue luminescent emission and luminescent enhancement effect are observed in complex 1 .  相似文献   

    

Delong Liu  Jing Ma  Hou Chen  Ping Yin  Naiyi Ji  Guangxi Zong 《Journal of polymer science. Part A, Polymer chemistry》2011,49(23):5109-5115

Zerovalent ytterbium (Yb) powder is firstly used as a catalyst in single electron transfer‐living radical polymerization of methyl methacrylate initiated by carbon tetrachloride in N, N‐dimethylformamide (DMF) and dimethyl sulfoxide, respectively. Polymerization proceeds in a “living”/controlled way as evidenced by kinetic studies and chain extension results, producing well‐defined polymers with controlled degree of polymerization and narrow molecular weight distribution. The apparent activation energy of polymerization in DMF is accounted to be 36.2 kJ/mol, and the energy of equilibrium state is calculated to be 13.9 kJ/mol. An increase in the concentration of Yb(0) yields a higher monomer conversion. It is observed that polymerization rate experiments a rapid increase in the presence of more polar solvent water, and increasing in the content of H₂O results in an increase in the apparent rate constant of polymerization, and a decrease in the molecular weight distribution. The reaction rate and molecular weight increase along with the decrease of DMF content. The effect of Yb(0) powder content, different ligands and concentration of initiator on the polymerization is also investigated. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

    

Guangxi Zong  Hou Chen  Zhi Tan  Chunhua Wang  Rongjun Qu 《先进技术聚合物》2011,22(12):2626-2632

Polyacrylonitrile (PAN) was grafted from surfaces of chloro‐modified silica‐gel with their surface chlorines as initiation sites, using an iron (III)‐mediated surface‐initiated atom transfer radical polymerization (ATRP) with activators regenerated by electron transfer (SI‐ARGET ATRP) method. The graft reaction exhibits first‐order kinetics with respect to the polymerization time in the low‐monomer‐conversion stage. The conversion of monomer (C%) and the percentage of grafting (PG%) increased with increasing of the polymerizing time and reached 23 and 730% after a polymerizing time of 24 hr, respectively. Hydroxylamine (NH₂OH·HCl) was used to modify the cyano groups of SG‐g‐PAN to obtain amidoxime (AO) groups. The AO SG‐g‐PAN was used to remove Hg²⁺. The adsorption kinetics indicated that the pseudo‐second‐order model was more suitable to describe the adsorption kinetics of AO SG‐g‐PAN for Hg²⁺. The adsorption isotherms demonstrated that Langmuir model was much better than Freundlich model to describe the isothermal process. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

    

Hou X  Zhang H  Jiang L 《Angewandte Chemie (International ed. in English)》2012,51(22):5296-5307

Over millions of years, complex processes of intelligent control have evolved in nature. Learning from nature is a continuing theme in the development of smart materials and intelligent systems. For example, biological nanochannels, which are typically ion channels, play a very important role in basic biochemical processes in cells. Inspired by ion channels, in which the components are asymmetrically distributed between the membrane surfaces, the generation of biomimetic smart nanochannels is a broad and varied scientific research field. The design and development of new biomimetic channels includes the use of different shapes of channels, different stimuli-responsive molecules, and different symmetric/asymmetric modification methods. In this Minireview, we summarize recent developments in building functional nanochannels by applying various symmetric and asymmetric modifications.  相似文献   

    

Valente C  Calimsiz S  Hoi KH  Mallik D  Sayah M  Organ MG 《Angewandte Chemie (International ed. in English)》2012,51(14):3314-3332

Palladium‐catalyzed cross‐coupling reactions enable organic chemists to form C? C bonds in targeted positions and under mild conditions. Although phosphine ligands have been intensively researched, in the search for even better cross‐coupling catalysts attention has recently turned to the use of N‐heterocyclic carbene (NHC) ligands, which form a strong bond to the palladium center. PEPPSI (pyridine‐enhanced precatalyst preparation, stabilization, and initiation) palladium precatalysts with bulky NHC ligands have established themselves as successful alternatives to palladium phosphine complexes. This Review shows the success of these species in Suzuki–Miyaura, Negishi, and Stille–Migita cross‐couplings as well as in amination and sulfination reactions.  相似文献