聚环氧氯丙烷-二甲胺粘土稳定剂合成及其防膨性能评价

文章采用环氧氯丙烷和二甲胺为原料,采用交联聚合法进行聚合,合成了聚环氧氯丙烷-二甲胺粘土稳定剂,探讨了合成条件并评价了粘土稳定剂的防膨性能。确定聚环氧氯丙烷-二甲胺的最佳合成条件为:反应温度70℃,反应时间5h以上,n(环氧氯丙烷):n(二甲胺)=1.5:1,n(乙二胺):n(环氧氯丙烷+二甲胺)=3%。该粘土稳定剂防止粘土膨胀性能良好,防膨率达到90.3%。     

压裂体系用粘土稳定剂的复配及性能评价

针对防膨剂在井深1500³000米的井下压裂施工的使用,通过室内实验复配了适用于此类油田的粘土稳定剂,其最佳复配工艺为:氯化钾10%,3-氯-羟基丙基三甲基氯化铵15%,水75%。该粘土稳定剂与压裂体系配伍性良好,冻胶不会出现破胶现象;与COP-1粘土稳定剂相比,其防膨率大大提高,高达95%;适用于低渗透油气田压裂施工体系。     

压裂用黏土稳定剂的筛选及室内评价研究

油田开发过程中,粘土矿物容易发生膨胀和运移,为了减少对储集层渗透率的伤害,需要在压裂液中加入粘土稳定剂。本文根据粘土稳定剂的分类和特点,进行体积压裂用粘土稳定剂的筛选试验,确定评价粘土稳定剂的标准和评价方法,研究温度和加热时间对粘土稳定剂的防膨效果的影响,以及对粘土稳定剂的耐水洗性能的评价,从而对粘土稳定剂进行筛选。研究表明:可以采用离心法测定防膨率,可知无机盐类中氯化钾的防膨效果最好,但是长效性差;有机类中聚二甲基二烯丙基氯化铵与乙二胺盐酸盐防膨效果较好。温度及加热时间对粘土稳定剂的防膨效果的影响较小。耐水洗实验方法大体可以说明无机类耐水洗性差,有机类较好;但是其室内评价方法还有待于研究。     

吸附型小分子粘土稳定剂的合成及性能研究

以环氧氯丙烷和三乙醇胺为原料合成了中间体三羟乙基环氧丙基氯化铵(TEPAC),再与多元醇及多元胺单体反应合成几种吸附型小分子粘土稳定剂。采用防膨、线性膨胀和岩屑回收等实验进行性能评价,通过XRD分析和粒径分布研究了其粘土稳定机理。结果表明,合成的几种吸附型小分子粘土稳定剂都有较好的防膨效果,防膨率最高可达85.2%;且具有良好的耐水洗性能、线性膨胀等多方面性能;多乙烯多胺-TEPAC加入后粘土颗粒粒径变小,单乙醇胺-TEPAC和乙二醇-TEPAC粘土颗粒粒径略有增加,主要起包裹和分散作用,抑制粘土膨胀;这3种吸附型小分子粘土稳定剂加入后粘土的层间距都略有缩小,说明这3种粘土稳定剂均具有一定压缩层间的作用。     

吸附型小分子粘土稳定剂的合成及性能研究

以环氧氯丙烷和三乙醇胺为原料合成了中间体三羟乙基环氧丙基氯化铵(TEPAC),再与多元醇及多元胺单体反应合成几种吸附型小分子粘土稳定剂。采用防膨、线性膨胀和岩屑回收等实验进行性能评价,通过XRD分析和粒径分布研究了其粘土稳定机理。结果表明,合成的几种吸附型小分子粘土稳定剂都有较好的防膨效果,防膨率最高可达85.2%;且具有良好的耐水洗性能、线性膨胀等多方面性能;多乙烯多胺-TEPAC加入后粘土颗粒粒径变小,单乙醇胺-TEPAC和乙二醇-TEPAC粘土颗粒粒径略有增加,主要起包裹和分散作用,抑制粘土膨胀;这3种吸附型小分子粘土稳定剂加入后粘土的层间距都略有缩小,说明这3种粘土稳定剂均具有一定压缩层间的作用。     

有机胺粘土稳定剂的合成及性能评价

以环氧氯丙烷、二甲胺为主要单体,乙二胺为交联剂,合成了3种有机胺粘土稳定剂,采用离心法测定粘土稳定剂的防膨性能及与无机盐复配性能.结果表明,粘土稳定剂EED合成最佳条件为：环氧氯丙烷与二甲胺摩尔比为1∶1,温度为60℃,反应时间为4h,交联剂乙二胺用量为单体总质量的2％.采用交联剂合成的粘土稳定剂EED防膨性能和复配性能优于未加交联剂的粘土稳定剂,稳定剂EED质量浓度为1.2％时,防膨率为88.96％,与无机盐复配后,防膨率进一步提高.     

阳离子防膨剂的室内性能评价研究

介绍了粘土稳定剂的分类和防膨机理,通过膨胀仪测量了KCI、阳离子聚丙烯酰胺、大阳离子聚合物PTA和小阳离子聚合物NW粘土防膨剂在不同浓度下粘土的静态膨胀量,综合比较哪种防膨剂效果更好。     

粘土稳定剂JA的合成与评价

用正交实验合成了阳离子聚合物粘土稳定剂JA,通过测定其阳离子度和特性粘数筛选出最佳合成条件.对粘土稳定剂JA在不同质量分数下的防膨性能进行了评价,确定了最佳使用质量分数范围为0.5%～1.0%.将JA与无机粘土稳定剂复配后进行评价,防膨效果较好,同时又能节约成本.     

靖边采油厂水敏性油藏粘土稳定剂研究

靖边采油厂长2储层粘土矿物质含量较高,属强水敏性地层,在注水过程中引起的储层伤害问题严重,水敏伤害高达72．5％,因此,对其进行储层保护意义重大。本文通过粘土防膨实验和岩心流动实验对NH4Cl、PCD,PDADMAC有机小阳离子化合物4种粘土稳定剂进行评价,在此基础上综合考察pH值变化对粘土稳定剂防膨效果影响。实验结果表明：粘土稳定剂配方为2％NH4Cl＋2％PDADMAC时,渗透率保持率高达95．20％,当注入水pH值在6-8之间时,该配方渗透率保持率为90．61％～95．20％,防膨性能稳定,对储层保护较好。     

小分子聚胺粘土稳定剂EM的合成及评价

以环氧氯丙烷和甲胺为原料合成了小分子聚胺粘土稳定剂EM,用离心法评价了EM的防膨性能。结果表明,当反应时间为6 h、反应温度为60℃、原料摩尔比为1.0∶1时,环氧氯丙烷转化率达到90%。当EM质量浓度为1.0%～2.0%时,防膨率达到72%～86%,能实现有效防膨;当EM质量浓度超过1.5%时,经清水浸渍24 h后,防膨率与原始防膨率相近,而无机盐粘土防膨剂的防膨率衰减到0,表明EM有优异的持久防膨性能;1.0%EM与0.5%NH4Cl复配,防膨率可达91%。     

Adsorption of alizarinate–micelle complexes on Na-montmorillonite

The adsorption on Na-montmorillonite of the monovalent anion alizarinate and its complexes with micelles of cationic surfactants was investigated. Micelles were prepared from octadecyltrimethylammonium (ODTMA) and benzyldimethylhexadecyl-ammonium (BDMHDA). Alizarinate–micelle complexes are much more efficient for the adsorption of the dye than alizarinate alone, e.g., from 0.05 mM alizarinate solution 12.5 mmol per 100 g clay was adsorbed in the presence of micelles, whereas only 4 mmol per 100 g clay was adsorbed in their absence. However, unlike the adsorption of alizarinate on the clay, where its adsorbed fraction increased with the concentration of the clay, in the presence of micelles, the concentration of the clay should be optimized for achieving maximal adsorption of alizarinate. This effect is due to monomer adsorption on excessive clay sites, which leads to the decomposition of micelles, and consequently, the adsorption of alizarinate is reduced.Visible spectra of alizarinate–micelle complexes in water and adsorbed on montmorillonite were recorded. The absorption band of alizarinate in aqueous solutions at 522 nm was red-shifted in the presence of ODTMA and BDMHDA micelles due to the effect of the micelle microenvironment. Further shifts were observed in the presence of montmorillonite indicating that the alizarinate–micelle complexes were adsorbed on the clay. Significant spectroscopic changes were observed after the adsorption of alizarinate–BDMHDA-micelle complex on the clay indicating that the adsorption leads to changes in the micelle. This observation suggests that the dye may serve as a probe in visible-spectroscopy study of the adsorption of micelles on clay minerals.     

Reusable high performance of calcined Mg/Al hydrotalcite for the removal of Navy Blue and Yellow F3G dyes

Water pollution with dye chemicals from apparel industries is a serious problem in the world.Since most of dyes are potentially have toxic and carcinogenic effects on human,it is important to remove them before they are discharged to the environment.Among many methods available for dyes removal in water,adsorption is the easiest and economically feasible that has no major obstacle for practical appli-cations.In the present study,we tested calcined Mg/Al hydrotalcite (Mg/Al CHT) prepared by co-precipitation technique as an adsorbent for the removal of Navy Blue (NB) and Yellow F3G (YF3G) dyes.Mg/Al CHT was characterized by using a Fourier transform infrared (FTIR) spectrometer,an X-ray diffrac-tometer (XRD) and a scanning electron microscope (SEM).The results showed that Mg/Al CHT was highly effective as an adsorbent for the removal of NB and YF3G under mild-acidic condition (pH 4) with removal capacities (b) according to Langmuir isotherm model were 7.97 × 10-4 and 5.80 × 10-4 mol·g-1,respectively.Kinetics study showed that the adsorption of NB and YF3D on Mg/Al CHT followed pseudo-second order with rate constant (kp2) 11.57 × 103 and 11.75 × 103 g·mol-1·min-1,respectively.The spent adsorbent can be easily regenerated by simply calcining it at 450 ℃ for 3 h.Adsorption test on the mix-ture of NB and YF3G showed that the adsorption capacity of Mg/Al CHT was eightfold higher than that of Mg/Al HT and the value was maintained with repeated use.     

Removal of Pb(II) from Aqueous Solution by Cross-linked Starch Phosphate Carbamate

The adsorption process of Pb(II) ions from aqueous solution by water-insoluble starch phosphate carbamates was investigated. The influences of adsorption conditions, such as adsorption time, adsorbent dose, pH, content of the substituent groups, initial Pb(II) concentration, and temperature, were thoroughly studied. It was shown that an adsorption time of 20 min is sufficient to reach the adsorption equilibrium, the adsorption equilibrium data follow well the Langmuir isotherm model, and the adsorption of Pb(II) ions on cross-linked starch phosphate carbamate is endothermic in nature. For the cross-linked starch phosphate carbamate (CSPC3) with a phosphate group content of 3.10 mmol/g and a carbamate group content of 1.40 mmol/g, the maximum adsorption capacity evaluated from the Langmuir isotherm towards Pb(II) is 2.01 mmol/g. In addition, repeated adsorption/desorption cycles were performed to examine the reusability of adsorbents and the recovery efficiency of Pb(II) ions. The adsorption capacity of Pb(II) ions by CSPC3 decreased from 1.85 to 1.47 mmol/g for three cycles.     

纳米黏土增强材料研究

玉山蒙脱土经提纯、钠化和有机插层处理后制得纳米黏土,阳离子交换容量为114 mmol/100 g土,晶层间距由1.238 nm增大到2.090 nm。采用挤水转相技术,以酯类为有机相置换纳米黏土中的水相,且m(有机相)∶m[纳米黏土(干土)]=100∶30,可防止纳米黏土的二次团聚,获得颗粒高度分散的纳米黏土增强材料。纳米黏土增强树脂的最佳质量分数为m(树脂)∶m(纳米黏土)=100∶5,用于环氧树脂时,冲击强度可提高302.3%,弯曲强度提高45.5%;用于聚丙烯树脂时,冲击强度提高35.7%。     

Effects of exchanged ammonium cations on structure characteristics and CO2 adsorption capacities of bentonite clay

Different alkali and alkaline earth cation forms of bentonite clay were exchanged with protonated mono-, di- and triethanolamine compounds, to study the effect of the exchanged ammonium cations on the structure characteristics, thermal behavior, surface properties and CO₂ adsorption capacities of bentonite clay. The revolution of the interlayer structure characteristics, thermal properties, the specific surface area and elemental analysis were characterized by XRD, FTIR, TGA, BET and CHNS techniques respectively, while the CO₂ adsorption capacities were gravimetrically measured by using magnetic suspension balance (MSB) equipment. It was found that the intercalation of ammonium cations into the interlayer space of bentonite clay induced a step change in its basal spacing, depending on their molar mass and the interlayer molecular arrangement. The presence of the characteristic IR peaks of amine compounds in the spectra of bentonite clay adsorbents modified by amines was qualitatively supported by the incorporation of ammonium cations in the interlayer space of bentonite, while the presence of C, H and N elements using CHNS technique was quantitatively confirmed by the intercalation process of amine compounds. It was also found that the molar mass of amines has an inverse effect on the amount of the adsorbed water (intensity), its desorption temperature (position) and the specific surface area of the synthesized materials. The CO₂ adsorption capacities on all the studied bentonite clay adsorbents modified by amines were found to increase between 2.68 and 3.15 mmol/g, compared to 0.93 mmol/g for untreated bentonite at the studied temperature and pressure. As expected, bentonite clay modified with di- and triethanolammonium cations showed lower CO₂ adsorption capacities than that treated with monoethanolammonium cations, due to their low specific surface area.     

Production and characterization of a novel hierarchical porous silica adsorbent for removal of methylene blue dye from wastewaters

Adsorption of methylene blue (MB) dye by hierarchical porous silica (HPS) is reported as a means of removing the dye from wastewater. HPS was produced through a sol–gel process by templating on rubber particles in skimmed natural rubber latex. The silica precursor was tetraethyl orthosilicate and the costructure directing agent was 3-aminopropyltriethoxysilane. Based on nitrogen-sorption, the HPS had a total pore volume of 1.0?cm³/g, a specific surface area of 237?m²/g, and a peak pore size of 4?nm. Larger pores (sizes >100?nm to 1?µm) were observed by scanning electron microscopy. The pores had an ink-bottle morphology of narrow necks connected to large cavities. The adsorption obeyed the Langmuir isotherm and was endothermic. Pseudo-second-order adsorption kinetics were observed. The specific adsorption of MB on HPS was 0.225?mmol/g at equilibrium. HPS was superior to many adsorbents reported for removing MB from aqueous media.     

丙烯酰胺共聚物AM/AA/NCD-离子液[equin]BF_4复合粘土稳定剂的合成及性能研究

采用丙烯酰胺(AM)、丙烯酸(AA)以及单六位取代烯丙胺基β-环糊精(NCD)为原料,合成出了一种水溶性聚合物AM/AA/NCD。采用喹啉、溴乙烷、氟硼酸钠在温和条件下合成了离子液体四氟硼酸1-乙基-喹啉盐([equin]BF4)。AM/AA/NCD溶液与[equin]BF4在50℃下回流,发生复合反应,生成AM/AA/NCD-离子液[equin]BF4复合粘土稳定剂。考察了反应条件对聚合反应的影响,确立了最佳合成工艺。通过膨润土线性膨胀实验,确定了复合粘土稳定剂最佳加量为0.6%,防膨率达到81%。采用X-射线衍射(XRD)考察了复合粘土稳定剂对钠蒙脱土晶层间距的抑制效果,晶层间距从1.89 nm降低到1.66 nm。压入硬度实验表明,AM/AA/NCD-[equin]BF4能有效保持泥页岩岩石强度。     

Saudi Arabian clays for lead removal in wastewater

Three types of local clays–Tabuk, Baha, and Khaiber–were tested for their abilities to adsorb lead ions from wastewater. The effect of pH on the adsorption of lead ions was also investigated. The clays were treated with hydrochloric acid to activate adsorption sites within clay particles. Untreated Tabuk clay had the largest adsorption capacity, about 30 mg lead/g clay, in comparison with those of Baha and Khaiber clays. The smallest adsorption was observed with Khaiber clay, about 10 mg lead/g clay; this may be attributed to the prior existence of lead within the clay. The adsorption of the acid-activated clays was not enhanced compared to those of untreated clays. The Langmuir model described the experimental data for all untreated clays, while the Freundlich model described the experimental data of untreated Khaiber clay and treated Baha clay. The local clays tested in this study, especially Tabuk clay, may be utilized as cost-effective and efficient adsorbent materials for removing heavy metals from wastewater in Saudi Arabia.     

活性白土/壳聚糖复合物吸附剂对果汁的澄清作用研究

利用简便的方法制备了活性白土/壳聚糖复合物吸附剂,并通过红外光谱(FT-IR)、热重(TG)、X-射线衍射(XRD)和透射电镜对所制备的吸附剂进行表征.结果表明,壳聚糖嵌入到活性白土的片层结构中,形成了稳定的复合结构,进而增大了活性白土的片层间距,有利于提高活性白土的吸附性能.活性白土/壳聚糖复合物作为吸附剂,对草莓汁、西瓜汁、橙汁均具有较好的澄清效果.对草莓汁澄清条件为:吸附剂用量为0.02 g,35℃、吸附时间1.5h、pH 5,澄清度为69.36％;对西瓜汁的澄清条件为:吸附剂用量为0.02 g,25℃、吸附时间1.5h、pH 6,澄清度达到98.42％;对橙汁的澄清条件为:吸附剂用量为0.02 g,30℃、吸附时间1h、pH 6,澄清度为61.08％.     

Removal of basic dyes from aqueous solutions using natural clay

Adsorption properties of natural clay (from Eski?ehir of Turkey) were investigated by depending on different adsorption conditions such as different initial dye concentrations and contact times. The chemical composition of the natural clay was analyzed by X-ray fluorescence spectrometry (XRF). The removal of basic dyes such as Nile Blue (NB) and Brilliant Cresyl Blue (BCB) from aqueous solutions using natural clay in this study was described. After the equilibrium adsorption time of 8 h, the adsorption capacities for NB and BCB reach about 25 mg/g and 42 mg/g, respectively. Lagergren kinetic equation was used to test the experimental data to examine the controlling mechanism of adsorption processes. Adsorption data of the BCB and NB onto natural clay were fitted well by the pseudo-first-order model. The adsorption isotherms data were correlated with the Freundlich equation and the Freundlich constants K_f (mg/g) and n (intensity of adsorption) were calculated. The r² (regression coefficients) values were 0.9835 and 0.9849 for NB and BCB, respectively. The adsorption capacities of natural clay for NB and BCB have the following order: BCB > NB.