三偏磷酸钠交联黄原胶的制备及其溶液流变性

以三偏磷酸钠(STMP)为交联剂,合成了水溶性低交联度黄原胶(XG),依据其溶液粘度优化出了最佳合成条件;考察了电解质质量分数、pH值及温度对STMP交联黄原胶(简记为SP-c-XG)溶液流变性的影响,并与XG溶液进行了对比。 结果表明,在所研究的电解质(NaCl和CaCl₂)质量分数(0~5.0%)、pH值(2~11)和温度(20~70 ℃)范围内,SP-c-XG和XG溶液的流变曲线均为假塑型,符合Herschel-Bulkley模型;其屈服值、表观粘度和动力学模量随电解质质量分数增大均先下降后上升,而随pH值的升高先升高后降低,随温度升高而降低。 SP-c-XG和XG溶液具有相似的流变性,但与XG溶液相比,SP-c-XG溶液具有更高的屈服值和表观粘度,特别是具有更强的弹性和耐温性,在油田强化采油领域具有重要应用前景。     

Mg-Fe-HTlc对黄原胶流变性的影响

研究了荷负电高分子物质黄原胶(XG)及类水滑石HTlc/XG复合悬浮体系的流体类型及触变性. 结果发现, 供试体系流变曲线都符合Herschel-Bulkley模型. 在0.05～0.20 wt%范围内, 随XG含量增加, XG溶液表现出由假塑性流体到塑性流体的转变, 没有触变性|1.5 wt%纯HTlc悬浮体系为牛顿流体, 无触变性. 当HTlc/XG质量比为29.0～6.5时(复合悬浮体系固含量保持为1.5%), 体系均表现为假塑性流体|除HTlc/XG质量比为29.0体系无触变性外, 其它复合悬浮体系均表现为正触变性.     

玻璃微流控芯片十二烷基硫酸钠无胶筛分电泳测定免疫球蛋白片段分子量

通过实验优化了葡聚糖筛分介质和运行缓冲溶液的浓度,采用十二烷基硫酸钠(SDS)无胶筛分电泳分离体系(10%(w/v)葡聚糖,0.1%SDS,10%甘油,0.2mol/LTris-硼砂,pH8.3的缓冲液)在自制的玻璃微流控芯片上高效分离了BODIPY衍生的蛋白质分子量标准样品,连续6次电泳所得迁移时间的相对标准偏差均小于0.50%。以6种蛋白质分子量的对数对其迁移时间作图,线性回归良好(r=0.994)。采用该芯片电泳分析体系对免疫球蛋白G不同片段的分子量进行了测定,所得结果与实际基本相符。     

Mg-Al MMH对除虫脲水悬浮剂流变性的影响

研究了Mg-Al型混合金属氢氧化物(MMH)质量分数(w)、温度和无机电解质对除虫脲水悬浮剂流变性的影响, 并采用Herschel-Buckley模型对流变曲线进行拟合. 实验结果表明, 稠度指数(KH)及屈服值(τH)均随w的增大而增大, w越大, 体系假塑性越明显, 且当w达到一定值后体系产生正触变性; 温度升高, KH和τH增大, 但不影响体系“剪切变稀”的假塑性特征和正触变性; 不同浓度的电解质对体系KH和τH的影响程度不同, 对于相同浓度的NaCl 和CaCl2, CaCl2对体系的影响更为显著, 但电解质的加入不改变体系“剪切变稀”的假塑性特征及正触变性.     

AM/AA/NAPA/NMQS两性离子共聚物的合成及表征

以丙烯酰胺(AM)、丙烯酸(AA)、N-烯丙基苯乙酰胺(NAPA)及N-甲基-N-烯丙基吗啉溴盐(NMQS)为原料,氧化还原体系下合成了一种水溶性两性离子共聚物AM/AA/NAPA/NMQS。最佳反应条件为:m(AM):m(AA)=4.0:6.0,NAPA 0.3 wt%,NMQS 0.15 wt%,引发剂0.1 wt%,pH=6,反应温度35℃,单体总浓度25wt%。对AM/AA/NAPA/NMQS四元共聚物进行了IR、1H NMR、SEM、特性粘数表征。当NaCl浓度为12000mg·L-1,CaCl2或MgCl2浓度为1200 mg·L-1时,溶液黏度保留率分别为13.7%、11.8%和12.7%;温度120℃时,溶液黏度保留率达到30.9%;当剪切速率在170 s-1时,溶液黏度保留率为24.6%。     

银离子对结冷胶/聚丙烯酰胺双网络水凝胶的增强作用

首先,以结冷胶(GG)为基体,丙烯酰胺(AAm)为单体,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,通过"一锅法"制备GG/PAAm双网络水凝胶(GG/PAAm DN);然后将GG/PAAm DN浸泡在硝酸银溶液中制得Ag~+增强的GG/PAAm DN(GG-Ag~+/PAAm DN)。通过扫描电子显微镜、流变仪、原子吸收光谱仪、力学性能测试等手段研究了AAm、MBA用量及Ag~+对水凝胶流变性能、微观形貌、力学性能的影响。结果表明:与GG/PAAm DN相比,GG-Ag~+/PAAm DN的储能模量升高,力学性能明显增强,压缩强度由4.88 MPa增大到11.8 MPa,,断裂伸长率由236%增大到320%,断裂强度由0.1MPa提高到0.26MPa。抗菌实验表明GG-Ag~+/PAAm DN具有良好的抗菌性能。     

微乳电动毛细管色谱在掌叶大黄指纹图谱上的应用

采用微乳电动毛细管色谱法(MEEKC)建立不同来源掌叶大黄的指纹图谱,为其质量控制提供依据。使用未涂层石英毛细管柱(75μm×65 cm,有效长度55 cm),采用的缓冲液为w(SDS)∶w(正丁醇)∶w(正辛烷)∶w(10 mmol/L硼砂溶液)=3.3∶6.6∶0.8∶89.3并通过添加10%的乙腈组成的O/W型微乳体系,分离电压18 kV,检测波长280 nm。结果通过聚类分析和相似度分析处理,14个掌叶大黄样品初步分为三类:道地药材,市售一般品和次品。本方法可用于掌叶大黄质量评价的有效手段,为MEEKC在中药指纹图谱研究中开辟了新的应用途径。     

鼠李糖脂应用于微乳毛细管电动色谱快速测定化妆品中激素类物质

采用生物表面活性剂鼠李糖脂建立了无需助表面活性剂的微乳体系,并应用于微乳毛细管电动色谱快速分析化妆品中皮质类激素泼尼松、泼尼松龙和氢化可的松。考察了pH值、鼠李糖脂浓度、离子强度、油相种类和浓度、分离温度、分离电压及进样电压和时间的影响,得出微乳体系最佳组成为0.1%(w/w)鼠李糖脂+0.8%(w/w)正庚烷+99.1%(w/w)硼砂缓冲液(80 mmol/L,pH 9.2)。分离温度20℃,分离电压20kV,电动进样10 kV×3 s,泼尼松、氢化可的松和泼尼松龙在9.4 min内可基线分离。重复进样7次,迁移时间和峰面积的RSD分别小于0.2%和5.0%。3种分析物线性范围均为5～100 mg/L;检出限分别为1.0,1.1和1.3 mg/L(S/N=3)。仅需简单萃取即可用于化妆品样品测定,回收率为81.6%～108%;RSD均小于4.8%。     

磷酸化黄原胶/氧化石墨烯的合成及其对铀的选择性吸附

以氧化石墨烯(GO)为基体,黄原胶(XG)为交联剂,磷酸(P)为修饰剂制备了磷酸功能化黄原胶/氧化石墨烯凝胶(P-XG/GO),并应用于铀的选择性吸附。扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、Zeta电势分析等技术表明GO的交联和磷酸化成功。系统研究了溶液pH值、铀初始浓度、吸附时间和温度等因素的影响,得到了适宜吸附条件。吸附数据用Langmuir等温线模型拟合良好,最大吸附能力为495.05 mg/g。与准一级动力学模型相比,准二级动力学模型更好地拟合了吸附过程。     

聚丙烯酸钠配合-超滤分离Hg(Ⅱ)、Cu(Ⅱ)和Cd(Ⅱ)

以聚丙烯酸钠为配合剂,研究了Hg(Ⅱ)、Cu(Ⅱ)和Cd(Ⅱ)混合溶液配合-超滤分离行为。考察了pH值和负载比LR对混合体系分离的影响,结果表明,pH=5适宜分离;当LR从0.01增大至2时,金属离子分离系数SHg-Cd和SHg-Cu逐渐增大,LR=2时达到最大值。在pH=5、LR=2、体积浓缩因子为15和各金属离子的初始质量浓度为30mg/L时,截留液中金属离子的质量浓度ρr,Hg、ρr,Cu和ρr,Cd分别为435.3、42.6和34.2mg/L;SHg-Cd、SHg-Cu和SCu-Cd基本不变,依次为229.3、184.3和1.2,即Hg(Ⅱ)得到选择性浓缩。浓缩液的洗涤研究结果表明,随着洗涤液体积增大,ρr,Hg基本不变,ρr,Cu和ρr,Cd分别下降至12.54和4.73mg/L。收集含Cu(Ⅱ)和Cd(Ⅱ)的各渗透液,调节LR=0.033和pH=5,浓缩16倍时,ρr,Cu从27.34mg/L升高至430.9mg/L,ρr,Cd从27.83mg/L仅升高至61.5mg/L,SCu-Cd为95.8,Cu(Ⅱ)获得选择性浓缩。     

三环已基锡L-扁桃酸酯配合物的合成、结构及性质

三环己基氢氧化锡与L-扁桃酸(物质的量比1:1)在苯和乙醇混合溶剂中反应合成了三环己基锡L-扁桃酸酯。 经X射线衍射方法测定了其晶体结构,配合物属斜方晶系,空间群为P2₁2₁2₁,晶体学参数a=0.80825(4) nm,b=1.77151(8) nm,c=1.8385(2) nm,α=β=γ=90°,V=2.6324(2) nm³,Z=4,D_c=1.310 g/nm³,μ(MoKα)=9.92 cm^-1,F(000)=1080,R₁=0.0472,wR₂=0.1341。 中心锡原子与环己基碳原子和氧原子构成畸型四面体。 对其结构进行量子化学从头计算,探讨了配合物的稳定性、分子轨道能量以及一些前沿分子轨道的组成特征。 研究了配合物的热稳定性、电化学性能、圆二色谱和体外抗癌活性。     

Influence of operating conditions on the retention of phosphate in water by nanofiltration

The objective of this study was to investigate the retention of phosphate anions, H₂PO₄⁻ and HPO₄²⁻, by nanofiltration. The first part of this study deals with the characterisation of the NF200 membrane used in permeation experiments with aqueous solutions of neutral organic and charged inorganic solutes. In the second part the effects of feed pressure, ionic strength, concentration and pH on the retention of phosphate anions were investigated. Results show that the membrane is negatively charged, its pore radius is around 0.5 nm and the retention order for the salts tested was R(Na₂SO₄) > R(NaCl) > R(CaCl₂). The retentions of phosphate anions are in the order of 85% for H₂PO₄⁻ and 96% for HPO₄²⁻. They are relatively high when compared to retentions of other anions with the same charge. The retentions of phosphate anions, particularly the monovalent species, depend on the chemical parameters (feed concentration, ionic strength, and pH) and applied pressure. The experimental data were analysed using the Speigler–Kedem model and the transport parameters, i.e., the reflection coefficient (σ) and solute permeability (P_s) have been determined.     

Structural and spectroscopic properties of Hexamethylenetetramine cobalt(II) complex: [Co(NCS)2(hmt)2(H2O)2][Co(NCS)2(H2O)4] (H2O)

Synthesis, structure, spectroscopy and thermal properties of complex [Co(NCS)₂(hmt)₂(H₂O)₂][Co(NCS)₂(H₂O)₄] (H₂O) (I), assembled by hexamethylenetetramine and octahedral Co(II) metal ions, are reported. Crystal data for I: F_w 387.34, a=9.020(8), b=12.887(9), c=7.95(1) Å, =96.73(4), β=115.36(5), γ=94.16(4)°, V=820(1) Å³, Z=2, space group=P−1, T=173 K, λ(Mo-K)=0.71070 Å, ρ_calc=1.718567 g cm⁻³, μ=17.44 cm⁻¹, R=0.088, R_w=0.148. An interesting two-dimensional network is assembled via hydrogen bonds through coordinated and free water molecules. The d–d transition energy levels of Co(II) ion are determined by UV–vis spectroscopy and calculated by ligand field theory. The calculated results agree well with experiment ones.     

Molecular weights of polystyrenes in toluene solutions by light scattering. Comparison between classical values and values deduced from a new method

Light scattering measurements in toluene solutions are performed for a series of monodisperse polystyrenes with a molecular weight M_w range from 4×10³ to 8×10⁶. The scattered polarized intensities I_v and the natural depolarization ratios ρ_n are registered with different apparatus at λ=633 or 488 nm and the M_w values are deduced through different formulae. The complete Carr and Zimm formula (CL_a), from I_v and ρ_n, and the usual simplified formula (CL_b), from I_v, are considered for the classical method. An already demonstrated formula is considered for the new method (New). Values of M_w and related parameters do not depend on the experimental systems used but deviations appear when using different formulae. The deviations are generally low (about 10%) but often systematic: M_w(CL_a)<M_w(CL_b)<M_w(New). The most important difference concerns the effect of destructive interferences for M_w>5×10⁵: the new formula leads to a lower increase from θ=90° to θ→0 for M_w values (θ is the observation angle). For instance, in the 8×10⁶ sample, M_w(θ→0)/M_w(θ=90°)=3.6 instead of 6.1, which implies a revision of the usual determination of the radius of gyration, R_g.     

Viscosity of aqueous calcium chloride solutions at high temperatures and high pressures

Viscosity of six (0.10, 0.33, 0.65, 0.97, 1.40, and 2.00) mol kg⁻¹ binary aqueous CaCl₂ solutions has been measured with a capillary-flow technique. Measurements were made at pressures up to 60 MPa. The range of temperature was from 293 to 575 K. The total uncertainty of viscosity, pressure, temperature, and composition measurements was estimated to be less than 1.6%, 0.05%, 15 mK, and 0.014%, respectively. The effect of temperature, pressure, and concentration on viscosity of binary aqueous CaCl₂ solutions was studied. The measured values of viscosity of CaCl₂(aq) were compared with data, predictions, and correlations reported in the literature. The temperature and pressure coefficients of viscosity of CaCl₂(aq) were studied as a function of concentration and temperature. The viscosity data have been interpreted in terms of the extended Jones–Dole equation for the relative viscosity (η/η₀) to accurate calculate the values of viscosity A- and B-coefficients as a function of temperature. The derived values of the viscosity B-coefficients were compared with the values calculated from the ionic B-coefficient data. The physical meaning parameters V and E in the absolute rate theory of viscosity and hydrodynamic molar volume (effective rigid molar volume of salt) V_k were calculated using present experimental viscosity data. TTG model has been used to compare predicted values of the viscosity of CaCl₂(aq) solutions with experimental values at high pressures.     

七水合三氯化铈-碘化钠催化氨基苯硫酚与高位阻α, β-不饱和酮的迈克尔加成反应

对七水合三氯化铈-碘化钠(CeCl₃·7H₂O-NaI)化邻氨基苯硫酚、 对氯邻氨基苯硫酚、 间氨基苯硫酚、 对氨基苯硫酚和对甲基苯硫酚与α,β-不饱和酮(1a~1o)的迈克尔加成反应进行了系统研究. 结果表明, CeCl₃·7H₂O-NaI-SiO₂复合催化剂能有效催化邻氨基苯硫酚及对氯邻氨基苯硫酚与α,β-不饱和酮(1a~1o)的迈克尔加成反应. 在优化的反应条件下, 即n(CeCl₃·7H₂O):n(NaI):n(α,β-不饱和酮)=1:2:2, m(CeCl₃·7H₂O):m(SiO₂)=1:1.6, 三氯甲烷作溶剂, 反应温度为回流温度, 反应时间为2 h, 反应可达到中等产率(43.1%~58.8%). 催化剂重复使用4次基本稳定. 此外, 提出了可能的催化机理.     

羟基磺基甜菜碱氟碳表面活性剂在油水界面的扩张粘弹性

氟碳表面活性剂是目前表面活性最高的特种表面活性剂,在三次采油等领域具有良好的应用前景。 用小幅周期振荡法研究了羟基磺基甜菜碱型氟碳表面活性剂(FS)在油-水界面的扩张粘弹性能,考察了振荡频率、FS质量分数、无机盐(NaCl、CaCl₂、MgCl₂)对FS在油-水界面的扩张粘弹性能的影响。 结果表明,FS溶液在油水界面的扩张模量、扩张弹性和扩张粘度随着FS质量分数的增加而出现最大值,随着频率的增大而略有增加。 加入无机盐时,扩张模量、扩张弹性随NaCl质量分数增大而出现最大值,而随着CaCl₂或者MgCl₂质量分数的增加,FS溶液的扩张模量、扩张弹性和扩张粘度减小,而当CaCl₂或者MgCl₂质量分数分别为0.05%、0.1%时,tanθ达到最大值。     

Relation of lattice ion solution composition to octacalcium phosphate dissolution kinetics

The kinetics of dissolution of octacalcium phosphate (OCP) has been investigated under conditions of constant relative undersaturation with respect to OCP, σ_OCP=−0.57, at pH 4.500, and ionic strength (I), 0.15 mol l⁻¹. The molar calcium/phosphate ratio (R) in the solutions was varied from 0.1 to 10. The dissolution rate decreased by 160% as R increased from 0.1 to 10. The ζ-potential of the OCP surfaces was measured in solutions equilibrated with respect to OCP at pH values ranging from 5.0 to 11. Under stoichiometric conditions (R=1.33), OCP was positively charged at pH values from 5.0 to 10. As the solution calcium concentration was increased, ζ became more positive over the entire pH range studied. At R=0.1, two isoelectric points were apparent at pH values of about 6.3 and pH 9.5. This behavior may be related to the solubility product (K_sp) of OCP. The relationship between surface characteristics and dissolution rate are discussed in terms of kink density and the kinetic ionic ratio model developed previously (J. Zhang, G.H. Nancollas, J. Colloid Interf. Sci., 200 (1998) 131.     

Synthesis and crystal structure of two novel nickel (imidazole) complexes having hydrogen-bonded networks

Two nickel (imidazole) complexes, Ni(im)₆Cl₂·4H₂O (1) and Ni(im)₆(NO₃)₂ (2) (im=imidazole) have been synthesized and characterized by elemental analysis, IR, UV, TG and single crystal X-ray diffraction. 1 crystallizes in the triclinic space group P-1 with a=8.800(6) Å, b=9.081(6) Å, c=10.565(7) Å, =75.058(9)°, β=83.143(8)°, γ=61.722(8)°, V=718.3(8) Å³, Z=1 and R₁ (wR₂)=0.0469 (0.1497). 2 crystallizes in the trigonal space group R-3 with a=12.370(6) Å, b=12.370(6) Å, c=14.782(14) Å, =90.00°, β=90.00°, γ=120.00°, V=1959(2) Å³, Z=3 and R₁ (wR₂)=0.0358 (0.0955). 1 and 2 exhibit different supramolecular network due to their different counter anions and different hydrogen bonding connection. In compound 1, [Ni(im)₆]²⁺ cation and counter anions Cl⁻ alternatively array in an ABAB fashion via N–HCl hydrogen bonding. In compound 2, the plane of each NO₃²⁻ is almost parallel and each NO₃²⁻ connect three different [Ni(im)₆]²⁺ cations via N–HO hydrogen bonding.