CTAB存在下纳米Pd粒子的超声诱导生长

在微量十六烷基三甲基溴化铵(CTAB)存在下,超声辐射PdCl2的乙醇水溶液,制得了纳米Pd粒子,用XRD、UV、TEM和HRTEM等进行了表征,探讨了超声诱导纳米Pd粒子的生长过程。结果表明,当超声辐射50min时,得到呈多边形的纳米Pd粒子,粒径分布较集中,大约为10nm。     

硼酸镧钙中三价铕离子的辐射跃迁参数

采用高温固相法合成了三价铕离子掺杂的硼酸镧钙(La2CaB10O19:Eu3+)荧光粉,XRD测试表明样品属单斜晶系。La2CaB10O19:Eu3+可被近紫外和蓝光LED有效激发,发射主峰位于617nm处,对应铕离子的5 D0!7F2跃迁。Judd-Ofelt强场参数表明,在La2CaB10O19:Eu3+样品中三价铕离子周围环境具有较强的共价性和反演非对称性。计算得5 D0!7FJ(J=1,2,4)的自发辐射跃迁概率分别为80.95、155.46和41.21s-1,最大受激发射截面分别为3.05×10-22、7.41×10-22和3.00×10-22cm2。有效的红光发射表明,La2CaB10O19:Eu3+荧光粉可以作为红色荧光色彩调节剂应用于白光LED。     

硼酸双甘油葡萄糖苷月桂酸酯的合成及性能研究

以甘油葡萄糖苷、硼酸为原料,以对甲苯磺酸做催化剂,与月桂酸经酯化反应合成硼酸双甘油葡萄糖苷月桂酸酯表面活性剂,并采用红外光谱仪、核磁共振谱仪表征产物结构.实验结果表明:硼酸双甘油葡萄糖苷酯作为中间体与月桂酸进行反应,以用量为反应物总质量0.5%的对甲苯磺酸为催化剂,用30 mL的乙腈作为溶剂,在80℃下反应150 min,得到目标产物;其表面活性剂的表面张力为36.0 mN/m(20℃),临界胶束浓度为1.16×10-2 mol/L,并显示出良好的乳化性能.     

Cationic substitution engineering achieves higher efficiency and thermal stability of Cr3+-activated phosphor for pepper (Capsicum annuum L.) development

Nowadays, near-infrared phosphor-converted light emitting diodes (NIR pc-LEDs) attract wide attention since the NIR spectroscopy technique can exert itself in many fields. However, most of the developed NIR phosphors are still not commercially viable, because of low internal/external quantum yield and poor thermal resistance. Therefore, it is urgent to develop an efficient irradiance and thermal stable NIR phosphor. In this work, the new GdAl_3-x-yGa_y(BO₃)₄: xCr³⁺ phosphors, compared with the original phosphor (x = 0.03, y = 0), when x = 0.03, y = 0.2, the luminescence intensity increased by 2.1 times, and the thermal resistance jumped from 92.0% to 96.7%. At the same time, with the increase of Ga³⁺, the spectra were gradually red shifted and FWHM widened, attributing to the nephelauxetic effect and the electron-phonon coupling effect enhanced, respectively. Particularly, under 420 nm excitation, the internal and external quantum yield of GdAl_2.77Ga_0.2(BO₃)₄: 0.03Cr³⁺ were 93.4% and 35.5%, respectively, which is higher than the previous research. The electric-optical conversion efficiency of the pc-LED was 10.76%. Finally, the phosphor application experiments revealed that the prepared phosphor has a very high commercial application potential.     

DEVELOPMENT OF SYNERGISTIC HEAT STABILIZERS FOR PVC FROM ZINC BORATE-ZINC PHOSPHATE

The importance of flame-retardant and smoke-suppressed poly(vinyl chloride) (PVC) compositions is increasing gradually in the polymer industry since PVC releases smoke and toxic gases (hydrogen chloride, HCl) during heating at temperatures above 140°C with the result of dehydrochlorination reaction. In this study, the synergistic effects of zinc borate (ZB)-zinc phosphate (ZP) on the thermal stability of PVC were investigated using thermal techniques. The induction and stability time values of PVC plastigels were obtained at 140° and 160°C. The results revealed that PVC plastigels having only ZP and ZB retarded dehydrochlorination of PVC compared with the unstabilized sample. However, the plastigels with both ZB and ZP had a superior synergistic effect on char formation of PVC. Since the induction periods of the samples having both ZB and ZP were higher than those of the unstabilized samples having only ZB or only ZP, the synergistic effect was observed.     

Synthesis of cationic polyacrylamide by aqueous two‐phase polymerization in poly(ethylene glycol) chloride solution

Aqueous two‐phase copolymerization of acrylamide(AM) and acryloyloxyethyl trimethyl ammonium chloride (DAC) was performed in poly(ethylene glycol) (PEG) solution and in PEG chloride(Cl‐PEG) solution, respectively. Series of cationic polyacrylamide(CPAM) aqueous dispersion were prepared using potassium persulfate (KPS) as initiator. The effect of total amount of monomers, the dosage of initiator, the content of dispersant, the mass ratio of AM to DAC, and the temperature on the conversion, molecular weight, cationic degree, and stability of aqueous dispersion were studied in detail. It is found that the increase of initiator and reaction temperature resulted in the increase of the final conversion, whereas the increase of DAC and PEG concentration resulted in the decrease of the final conversion. The optimum reaction conditions of synthesis were as follows: (1) PEG‐H₂O system: PEG 7.5 g, AM 8 g, DAC 2 g, KPS 0.05 g, H₂O 100 mL, 70°C. In this process conditions, the molecular weight of CPAM was 3.21 × 10⁶, the cationic degree of CPAM was 24.4%, the storage stability of the aqueous dispersion was over 3 months. (2) Cl‐PEG‐H₂O system: Cl‐PEG 7.5 g, AM 8 g, DAC 2 g, KPS 0.05 g, H₂O 100 mL, 65°C. In this process conditions, the molecular weight was 3.68 × 10⁶, the cationic degree was 23.3%, and the storage stability of the aqueous dispersion was over 6 months. In general, the stability of CPAM aqueous dispersion in Cl‐PEG system is much better than in PEG system. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Dehydration,Water Vapor Adsorption and Desorption Behavior of Zn[B3O3(OH)5] · H2O and Zn[B3O4(OH)3]

The dehydration behaviors of two different hydrated zinc borate species, Zn[B₃O₃(OH)₅] · H₂O and Zn[B₃O₄(OH)₃], which are industrially important flame retardants, were studied by thermal gravimetric(TG) analysis and in situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. Dehydration onset temperatures of Zn[B₃O₃(OH)₅] · H₂O and Zn[B₃O₄(OH)₃] were 129 and 320°C, respectively, at a 10°C/min ramp rate. A very small amount of boric acid was volatilized in addition to water vapor when both samples were heated at 250°C. A significant amount of water vapor was adsorbed by Zn[B₃O₃(OH)₅] · H₂O from air at 25°C. However, Zn[B₃O₄(OH)₃] adsorbed a very small amount of water under the same conditions. Both zinc borates did not have a tendency to cake during storage.     

一种新型有机硼交联剂与硼砂交联剂的对比

从瓜胶压裂液的粘度、交联时间、粘时性、滤失性和破胶性五方面,评价了有机硼ALP-3和硼砂交联剂对压裂液冻胶性能的影响。结果表明,两种交联剂均能满足现场施工要求,但新型有机硼交联剂更适用于温度较高、井深较大的油气井。     

硼及硼酸盐产品开发和应用前景

论述了硼及硼酸盐在现代无机盐工业中的地位和作用,以及在国民经济各部门、工农业生产、国防工业以及高新技术领域的应用。结合国内外硼化物的发展趋势,并根据中国的实际情况提出了当前应开发和发展的硼、硼酸盐及含硼新型材料有:纤维复合材料、元素硼粉和同位素系列产品、硼金属化物(如硼化钙、硼化锆、硼化钛)和含硼非晶态金属材料、有机硼化物(硼酸酯、烷基硼)、氟硼酸盐、硼酸钙、硼酸锌、硼酸镁和硼酸铝晶须材料。     

超声波改性OTMAC-凹凸棒土吸附苯酚

采用超声波技术,对凹凸棒土进行十八烷基三甲基氯化铵改性,研究改性凹凸棒土对苯酚吸附的工艺条件。以苯酚去除率为指标,探讨了振荡时间、温度、速度、凹凸棒土用量对苯酚去除效果的影响,并且通过正交实验得出了吸附苯酚的最优化工艺条件为：振荡时间60mins,粘土用量2．5g,振荡温度25℃,振荡速度140r／min。该条件下,苯酚去除率迭60．4％。通过FTIR分析和吸附等温线的绘制探讨了OTMAC-凹凸棒土的改性效果以及对苯酚的吸附机制。