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生物吸附剂—虾壳吸附镉(Ⅱ)的实验研究 总被引:1,自引:0,他引:1
本文采用廉价的生物吸附剂一虾壳来吸附水中的Cd^2 ,研究溶液的pH值,初始Cd^2 离子浓度,虾皮不同粒度,外加盐等因素对Cd^2 的吸附特性的影响,探讨了经过一定浓度酸处理的虾壳对Cd^2 的吸附情况,得到了最佳的pH值,得出了适宜的吸附等温线经验方程。 相似文献
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为了研究纳米碳酸钙和纳米添加剂在促进燃煤脱硫中的特性,在ZCS-1智能测硫仪中进行纳米碳酸钙脱硫实验研究。结果表明,在炉温900℃、钙硫比为2的条件下,脱硫效率高达90%;1 150℃时达到50%以上。三种纳米碳酸钙的脱硫效果明显好于普通碳酸钙。研究还表明,粒径越小,脱硫效果越好;不同煤种对脱硫效率有较大影响,主要和煤中硫分的含量和硫的分布形态有关;温度是决定脱硫效果的主要因素,900℃下效果最好,超过1 100℃后效果明显下降。SEM和BET分析结果表明,纳米碳酸钙促进脱硫主要是由于其较为丰富的孔隙结构。添加纳米Al2O3和纳米ZnO都能在一定程度上促进纳米碳酸钙脱硫。其中,纳米Al2O3的效果较好,1 150℃能使脱硫效率提高20%左右,达到62%以上。 相似文献
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晶体的晶型和形貌是碳酸钙制备中的关键问题之一。 采用尿素水解均匀沉淀法来控制碳酸钙的晶型和形貌。 利用XRD和SEM等技术手段对CaCO3晶体的结构和形貌进行了表征。 结果表明,高温条件下(90 ℃)水溶液中得到均匀的针状结构的文石晶体。 添加适量柠檬酸钠后,则得到的是特殊形貌的方解石晶体。 在乙醇/水混合溶剂中,柠檬酸钠对CaCO3晶体的形貌也有重要影响,通过改变乙醇体积分数,得到了中空绒毛球状的球霰石。 相似文献
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具有包藏结构的三元聚丙烯纳米复合材料结构与性能关系的研究 总被引:2,自引:0,他引:2
制备了一种新型聚丙烯 丁苯橡胶 纳米碳酸钙三元纳米复合材料 .研究结果显示 ,复合材料中的大多数纳米碳酸钙粒子被包藏在丁苯橡胶中 ,并与之共同形成分散于聚丙烯树脂中的分散相 ,这种聚丙烯纳米复合材料具有高刚性、高韧性、高耐热性和高的结晶速率 .系统研究了成核剂苯甲酸钠的加入和纳米碳酸钙的用量对该类纳米复合材料相态结构、结晶形态和结晶动力学的影响 ,以及具有包藏结构的分散相粒径和PP中β晶含量对材料性能的影响 .结果表明 ,苯甲酸钠的加入和纳米碳酸钙用量的提高均可使体系中分散相粒径减小 ,结晶速率加快 ,进而使材料的韧性、刚性和耐热性提高 . 相似文献
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天然橡胶特有的应变诱导结晶能力赋予其优异的力学性能.异戊橡胶作为唯一能够替代天然橡胶的合成橡胶品种,其应变诱导结晶能力受到关注.本文对3种异戊橡胶的微观序列结构进行了分析,并研究了其结晶性能.核磁分析结果表明:3种异戊橡胶的顺-1,4-结构含量差别不大;从1,4-结构单元的键接方式(序列结构)看,SKI-5和YS-IR分子链中顺-1,4-结构单元均以头-尾相接的方式沿分子链排列,不存在头-头键和尾-尾键接方式;SKI-3中约有0.4%~0.5%的1,4-单元采取头-头键接方式,约有0.3%~0.6%的1,4-单元采取尾-尾键接方式;根据定量计算结果,从分子链上1,4-结构单元的序列分布来看,SKI-3的规整性与SKI-5、YS-IR相近或略高.XRD研究结果表明:炭黑填充的天然橡胶硫化胶拉伸至400%以上时发生取向结晶;而炭黑填充的异戊橡胶硫化胶需拉伸至500%以上时才发生取向结晶.基本物理机械性能研究表明:3种异戊橡胶的性能相当,拉伸强度和撕裂强度明显低于天然橡胶;由于结构和组成上的差异,异戊橡胶的结晶能力较天然橡胶差. 相似文献
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St / AA共聚物的组成对碳酸钙结晶及形貌影响的研究 总被引:1,自引:0,他引:1
在聚苯乙烯-丙烯酸两亲共聚物(简称PAS)溶液中制备CaCO3,用XRD、FTIR和SEM等研究随着PAS的亲水AA和亲油St单元组成的变化所引起的聚合物分子链段、溶解性质和胶束空间构象等的改变对CaCO3晶型和形貌的影响。结果显示:随着亲水性AA单元组成的提高,可以由AA链段的晶面匹配成核调控碳酸钙为方解石纳米晶,并因PAS在水溶液中溶解性不同,形成了多种碳酸钙形貌的聚集体;当St和AA的物质的量比为3∶1时,合成出类珍珠岩层碳酸钙结构。根据PAS的结构性质和在水溶液中的溶解行为初步探讨了类珍珠岩层碳酸钙的形成机理,认为是PAS基质模板和羧酸根对钙的键合作用形成这一特殊形貌碳酸钙。 相似文献
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分别采用煅烧法、电位滴定法及络合滴定法定量测定3种卷烟纸中CaCO3的含量,发现煅烧温度和时间对煅烧法的测定结果影响很大,当煅烧温度为900 ℃,煅烧2 h时卷烟纸中的纤维可完全氧化分解;电位滴定法和络合滴定法的结果具有较高的稳定性,但卷烟纸中的金属氧化物和碳酸盐易给电位滴定法带来误差,络合滴定法通过遮蔽剂可消除杂质离子的影响,具有较高的准确性。对3种卷烟纸灰分的XPS分析结果表明,灰分中除CaO外,还含有C、Na2CO3、Na2SiO3、Na3PO4、CaSiO3、Ca3(PO4)2等物质;SEM分析结果表明CaCO3呈纺锤状微晶和团簇状体分布在纤维中。该研究结果提供了一种比较准确的定量测定纸张中CaCO3含量的方法。 相似文献
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Chitin has been extracted from Philippine blue swimming crab. The extracted chitin was subjected to thermo gravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) analysis The degree of acetylation of the extracted chitin, derived from the X-ray diffraction intensity values of chitin characteristic peaks, revealed that the extracted chitin is purer than the commercially acquired high purity chitin. The extracted chitin was used to form polymer films at different formation conditions. Polymer films were also formed from commercially acquired chitin for comparison. It was shown that films prepared from the extracted chitin at different conditions have greater ultimate tensile strengths as compared to the commercially-available plastic film. Morphologies of the material surface and the fracture surface were investigated using the scanning electron microscope to identify stress concentration sites that contributed to the weakening of material under tensile loading. 相似文献
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采用扫描电镜(SEM)、热重分析(TG)、傅里叶变换红外光谱(FTIR)及白度测试对三角帆蚌贝壳与其养殖的珍珠研磨粉进行了对比研究。结果表明:1珍珠粉的υ2谱带较于贝壳粉的该谱带存在约1~3cm-1的蓝移,两者文石中的υ1与υ4谱带具有较好的一致性;2 SEM观察下,粉体的颗粒粒径大小与形貌特征并不能作为贝壳粉与珍珠粉区分鉴别的依据。3随煅烧温度的升高,贝壳粉与珍珠粉的白度先下降后升高,珍珠粉白度降低的速率高于贝壳粉,且煅烧后珍珠粉的白度最低值低于煅烧贝壳粉的白度最低值。 相似文献
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method for analysis of the edible oil with crab taste by gas chromatography has been developed. The sample was directly introduced on a Silicone XE-60 capillary column . 25m×0. 25mm×0. 5μm, with a one-ramp temperature programming (hold 10min at 80℃, increased upto 180℃ at 20℃/min and then hold 20min) and detected by FID. For the component identification mass spectrometry was used. The above condition was chosen after in comparison with a PEG-20M column. 相似文献
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首先采用一次乳化法制备出PLGA[聚(乳酸-羟基乙酸)]纳米微球,并通过静电吸附将阳离子聚合物壳聚糖修饰到PLGA微球表面,然后以香草醛为交联剂对壳聚糖进行化学交联,得到一种壳交联的p H响应型纳米微球(PCV),微球粒径为(277.60±38.01)nm,表面电位为(21.60±4.51)m V.微球稳定性评价结果显示微球在24 h内粒径变化较小;流式细胞仪检测显示细胞对PCV微球的摄取量比未经修饰的PLGA微球的摄取量高;空白微球细胞毒性实验表明在空白微球浓度小于80μg/m L时细胞的存活率达93.24%.以多西他赛(DTX)为模型药物进行包载,该纳米微球DTX的载药率为7.48%,包封率为34.98%;体外药物释放实验显示,该微球在p H=5.0环境下孵育90 h的药物积累释放率达58.66%,而在p H=7.4的环境下的药物积累释放率为50.63%;此外,载DTX微球毒性试验结果表明该载药微球对A549肺癌细胞有较强的杀伤作用,其IC50值可达0.0009μg/m L. 相似文献
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《Arabian Journal of Chemistry》2014,7(6):1166-1177
This study highlights the importance of a cheap bio waste; Pine Nut Shell (PNS), from which a carbon is synthesized that can efficiently remove toxic phthalates from an aqueous system. PNS derived carbon shows high affinity toward phthalates in descending order along with adsorption capacity i.e., dibutyl phthalate (DBP) 5.65 mg/g > diallyl phthalate (DAP) 3.64 mg/g > diethyl phthalate (DEP) and 2.87 mg/g > dimethyl phthalate (DMP) 2.48 mg/g. Different characterization techniques such as FTIR, elemental analysis, point of zero electric charge (PZC), SEM, EDX and BET were employed to investigate the binding sites and surface area of the adsorbent. Adsorption experiments were performed both in batch and column modes. Equilibrium studies showed that the Langmuir isotherm fits best to experimental data. Kinetically, adsorption phenomena obeyed pseudo second order. Furthermore, thermodynamic results expressed the exothermic nature of adsorption on the basis of negative value of enthalpy change. Column sorption method was also adapted to check the feasibility of the adsorption process through the investigation of flow rate, breakthrough curve and pre-concentration factor which is found to be 13 for DMP and DEP and 16 for DAP and DBP. Methanol was found to be best solvent for the recovery of phthalates. Application in real water samples also showed good efficiency of PNS derived carbon for the removal of phthalates. 相似文献
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In Indonesia, the use of ground water is increases. It contains minerals, especially calcium and magnesium, at high concentration. This causes problems such as the crust on household appliances and higher use of soap for washing. Shell of Pistacia vera l. were study as an adsorbent of Ca and Mg in the matrix artificial hard water. Pistacia v. shell were dried and crushed into powder form. A batch experiment with various parameters was used in this research. Optimum adsorption conditions is at pH 8 and the weight of Pistacia v. shell is 1.5 g. Adsorption capacity of Ca and Mg, respectively 2.41 and 2.19 mg/g. Based on the research results, it can be concluded that the Pistacia v. shell is a very potential as a biodegradable, easy and inexpensive bioadsorbent to adsorb Ca and Mg. 相似文献
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《Analytical letters》2012,45(16):1327-1334
Abstract Paper chromatographic separations of 34 organic acids on calcium carbonate and calcium sulphate impregnated paper has been developed. Tricarboxylic acids, dicarboxylic acids, amino acids, and keto acids and their derivatives can be separated in simple solvents such as acetone, ethanol, water, aqueous sodium chloride, ammonium chloride and calcium nitrate. Important separations achieved are: Adipic from maleic and malonic, cis-aconitic from I-cystine and nicotinic, citric or tartaric from ascorbic, gallic, malic and salicylic, I-aspartic from arginine-HCl, fumaric and glutamic, barbituric from hippuric and α-ketoglutaric, benzoic from ρ- & m-nitrobenzoic and cis-aconitic from trans-aconitic. 相似文献
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热重分析法研究贝壳固硫反应动力学 总被引:2,自引:0,他引:2
采用热分析法研究了贝壳和石灰石固硫反应过程, 用等效粒子模型对固硫反应过程进行了表征, 计算分析了其固硫反应动力学参数. 结果表明, 贝壳比石灰石含有较多的碱金属盐, 其作用是提高了贝壳固硫反应速率常数和有效扩散系数. 贝壳固硫反应中存在补偿效应. 根据等动力学温度判别固硫剂活性适用于不同反应控制区的活性判断. 碱金属成分对钙基固硫剂活性有正负两个方面的影响, 含量过大或过小都会削弱固硫剂活性, 因而存在最适含量. 在1 073~1 273 K温区固硫时, 钙基固硫剂中碱金属离子与钙离子摩尔比为1∶50左右时固硫活性较高. 相似文献
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采用废弃蟹壳为碳源,KOH为活化剂原位制备了氮/氧共掺杂多孔炭,并研究其作为电极材料在超级电容器中的应用。 固定蟹壳与KOH的质量比为5:3,考察了煅烧温度对所得炭材料产率、孔结构和氮氧含量的影响。 结果表明,蟹壳基炭材料的孔结构和氮/氧含量可通过改变煅烧温度调变。 随着煅烧温度从500 ℃上升至700 ℃,多孔炭的比表面积和孔体积逐渐增大,而氮/氧含量随温度升高则降低。 采用循环伏安和恒流充放电对所得材料的电化学性能进行测试。 结果表明,所得多孔炭的电化学性能取决于其孔结构与氮/氧表面性质的协同作用,其中煅烧温度为600 ℃所得的多孔炭比表面积为612 m2/g,氮和氧含量分别为3.53%和32.8%,在50 mA/g的电流密度下比电容达到310 F/g,循环1000次比电容仍然保持95%以上,展现出良好的电化学性能。 相似文献