稻糠基磁性高吸油材料的仿生制备及性能研究

利用多巴胺的自聚合作用使Fe_3O_4纳米粒子固载于稻糠表面,进而采用十八胺进行样品表面疏水改性,制备得到稻糠基新型磁性疏水吸油材料。利用扫描电子显微镜、傅里叶变换红外光谱、X射线衍射、磁滞回线和接触角测定等技术对制备的样品进行了表征。实验结果表明,多巴胺改性成功实现了Fe_3O_4纳米粒子在稻糠表面的固载,所制得的稻糠基吸油材料具有较好的磁性,其磁饱和强度达39.6emu/g,样品的接触角达135°,具有高疏水性。在对三氯甲烷等七种油性物质的吸油实验中发现,稻糠基新型磁性疏水吸油材料的最高吸油量可达自身质量的6.83倍,且样品的适用范围广、重复利用率高。     

高稳定性导热油基磁性流体的制备

以氨水为沉淀剂、油酸为表面改性剂制备了高稳定性导热油基磁性流体.研究了所制备的Fe3O4粒子和磁性流体的各项性能.结果表明,制备的Fe3O4粒子晶型完整、粒径均一,具有很高的饱和磁化强度.通过表面改性油酸成功地包覆到Fe3O4粒子表面.所制备的导热油基磁性流体具有强磁性和高稳定性.     

油酸钠对油相法制备的Fe3O4纳米粒子的表面改性研究

以常见的表面活性剂油酸钠作为表面改性剂,通过油酸根离子中的脂肪烃链与高温油相法制备的Fe3O4纳米粒子表面的亲油性基团之间的范德华力作用,将分散在油相中的Fe3O4纳米粒子转移到水相中.研究了油酸钠浓度、油相中Fe3O4纳米粒子含量、pH值及温度等条件对改性结果的影响;用穆斯堡尔谱仪（Moessbauer）、透射电镜（TEM）、傅立叶红外光谱（FT-IR）等方法对改性前后的样品进行了表征.结果表明：本方法可有效地将油相法制备的Fe3O4纳米粒子从油相中转移到水相.当油酸钠浓度为3mmol/L、Fe3O4纳米粒子在正己烷中浓度为12.28mg·mL^-1、pH为8.6且温度为60℃时,转移率最高可达86%,改性后粒子在水相中的含量最高可达10.5mg·mL^-1;改性后磁性粒子在水相中含量较低时,能够稳定分散较长时间.     

核-壳型罗丹明6G磁性分子印迹固相萃取材料的合成与表征

采用化学共沉淀法制备Fe3O4磁性纳米粒子,以3-氨丙基三乙氧基硅烷(APTES)对其表面进行氨基硅烷化改性,形成Fe3O4@SiO2-NH2纳米粒子。以其作为磁性核,采用表面印迹技术,以罗丹明6G为模板,丙烯酰胺(AM)为功能单体,三羟甲基丙烷三甲基丙烯酸酯(TRIM)为交联剂,在Fe3O4@SiO2-NH2表面形成罗丹明6G分子印迹聚合膜,制备了核-壳型罗丹明6G磁性分子印迹聚合物(Fe3O4@MIPs),对合成条件进行了优化。分别采用红外光谱(FT-IR)、场发射扫描电镜(FESEM)、振动样品磁强分析(VSM)和热重分析(TGA)等仪器分析手段,对Fe3O4@MIPs的结构进行表征。结果表明,所制备的核-壳型磁性分子印迹聚合物具有高吸附容量及显著选择性;在外加磁场作用下Fe3O4@MIPs可快速与样品基质分离,大大提高了实验效率。Fe3O4@MIPs作为一种新型固相萃取材料,可以从样品中选择性分离和富集违规添加的罗丹明6G,可应用于食品的安全检测。     

多聚磷酸钠改性水基Fe_3O_4磁流体的制备与表征

采用多聚磷酸钠(STPP)对Fe3O4磁性纳米粒子进行表面改性,制备稳定的水基磁流体。通过傅里叶变换红外光谱(FTIR)、热重分析(TG)、透射电镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、振动样品磁强计(VSM)及Zeta电位仪对所制备的磁流体进行表征。结果表明,STPP包覆于Fe3O4磁性纳米粒子的表面,当pH>3时,粒子表面带有负电荷;磁性测试结果表明,STPP/Fe3O4磁性纳米粒子具有超顺磁性,其饱和磁化强度为62.3 A.m2.kg-1。     

油酸对微波水热法制备的纳米Fe_3O_4的影响

采用微波水热法制备纳米Fe3O4,并用油酸对其进行表面改性,获得油酸包覆的Fe3O4纳米粒子。利用XRD、FT-IR、TEM和振动样品磁强计对Fe3O4纳米粒子的结构、形貌、磁性能进行表征。结果表明:表面改性使得油酸分子中—COOH和Fe离子形成化学键;改性后的纳米Fe3O4粒子为粒度均匀的球形,具有良好的分散性,平均粒径约8nm;该产物具有超顺磁性,饱和磁化强度为61.8emu/g。     

纳米Fe3O4/聚苯胺复合粒子的制备及其磁性能研究

用水解沉淀法制备纳米Fe3O4,然后在其溶液中原位合成聚苯胺,得到纳米Fe3O4/聚苯胺复合粒子.通过XRD、TEM、JDM等测试对纳米复合粒子的形态、结构及磁性能进行了研究.实验制备的纳米Fe3O4粒子粒径为30nm左右,在其表面沉积聚苯胺后,复合粒子的粒径达到了50nm左右.与纳米Fe3O4粒子相比,纳米Fe3O4/聚苯胺复合粒子的XRD峰形变得更为明锐.纳米复合粒子的磁性能表现出软磁性,与纳米Fe3O4粒子相比,矫顽力减小为0,这可以大大减小材料的磁滞损耗和退磁难度,性能得到改善.     

磁性羧甲基化壳聚糖纳米粒子的制备与表征

以化学共沉淀法制备了Fe3O4纳米粒子,壳聚糖经羧甲基化改性后接枝在Fe3O4颗粒表面,得到了磁性羧甲基化壳聚糖(Fe3O4/CMC)纳米粒子.利用透射电镜(TEM)、X射线衍射(XRD)、傅立叶红外光谱(FT-IR)及磁性测试对产物进行了表征.TEM表明Fe3O4纳米粒子被CMC包覆,粒径约10 nm;XRD分析表明复合纳米粒子中磁性物质为Fe3O4;FT-IR表明壳聚糖发生羧甲基反应以及在Fe3O4表面的接枝反应.Fe3O4/CMC纳米粒子具有超顺磁性,比饱和磁化强度25.73 emu/g,有良好的磁稳定性.     

超顺磁性Fe3O4纳米颗粒的制备及修饰

利用2-吡咯烷酮和乙酰丙酮铁为原料制备出Fe3O4磁性纳米粒子,选择偶联剂γ-氨丙基三乙氧基硅烷(NH2C3H6Si(OC2H5)3)对磁性材料进行了表面修饰.经XRD、TEM、VSM、FT-IR测试结果表明,制备出的Fe3O4磁性纳米粒子粒径均一(8～10nm)、结晶度高、磁响应较强;通过控制反应回流时间,可以改变粒子的大小;经表面改性以后,-OH、-NH、-NH2、-C-O、-C-OH等多种功能基团负载到磁性Fe3O4纳米粒子表面,增强了微球的生物相容性.     

改性Fe3O4纳米粒子在磁性复合超滤膜中的应用

为解决Fe3O4纳米粒子在磁性复合超滤膜中发生团聚和分布不均匀的问题,文中以市售20nm的Fe3O4粒子为对照,添加自制的改性Fe3O4纳米粒子制备出Fe3O4-聚砜(PSF)磁性复合超滤膜(改性复合超滤膜)。经扫描电镜观察膜表面形貌、能谱仪扫描复合膜中Fe元素分布以及铸膜液中Fe3O4纳米粒子分布情况分析和复合膜孔径分布测试后表明,改性后复合超滤膜中纳米粒子的分布较改性前更为均匀,且未出现粒子团聚现象,改性效果明显。由改性前后的复合膜在不同磁场下对聚乙二醇6000和10000的截留率呈现几乎相同的变化趋势可知,添加改性粒子并未改变磁性复合膜的分离特性。     

表面处理对PVC/稻壳复合材料吸湿性能影响研究

研究了硅烷偶联剂与酚醛树脂改性稻壳粉及填充PVC后对复合材料吸湿性能、力学性能影响.结果表明:用硅烷偶联剂与酚醛树脂复合改性的PVC/稻壳粉体系吸湿量、吸湿后的膨胀率低于单一的硅处理及未处理的复合材料,同时复合改性的PVC/稻壳粉体系力学性能明显优于其它复合材料.     

表面改性对PVC/稻糠发泡复合材料的影响

研究了纳米CaCO3、硅烷偶联剂、甲基丙烯酸甲酯(MMA)改性稻糠对PVC/稻糠发泡复合材料性能的影响.结果表明:纳米CaCO3能改善稻糠的耐热性,用硅烷偶联剂处理稻糠的发泡复合材料冲击性能好于用MMA微波处理稻糠发泡复合材料;而用MMA微波处理稻糠的发泡复合材料在拉伸性能、弯弹性模量及加工性能优于硅烷偶联剂处理的稻糠发泡复合材料.     

膨胀石墨的毫米波二维平面衰减性能研究

本文报道了不同长度膨胀石墨蠕虫的毫米波二维平面衰减实验结果 ,并将其与传统的微波干扰材料———铝箔条的毫米波衰减性能作了对比研究。结果表明 ,尽管膨胀石墨蠕虫在物理形状上与铝箔条有相似之处 ,并且具有一定的导电性能 ,但其对毫米波的衰减特性并不符合半波谐振子模型所推导出的结论。膨胀石墨蠕虫对毫米波的衰减为散射和吸收作用的综合结果。     

Synthesis of pH-sensitive water and oil dual-absorption material using microemulsion polymerization process

pH-sensitive water and oil dual-absorption material (WODAM) has been successfully synthesized through microemulsion polymerization. Firstly, microemulsions prepared with monomers were analyzed by pseudo-ternary phase diagram. In addition, conductivities of microemulsions were tested to identify microemulsion types. Meanwhile, the factors that affected microemulsion types were analyzed. Then WODAMs were prepared, and the chemical structure was characterized using Fourier transform infrared (FTIR) spectroscopy. Liquid absorption tests indicated that both monomer ratio and microstructure of WODAMs had influences on their water absorption rate (WAR) and oil absorption rate (OAR). In addition, pH sensitivity tests showed that WODAM absorbed much water in neutral and weak alkaline solutions, but little water in strong alkaline solutions. What’s more, liquid absorption tests in cement slurry filtrate (CSF) showed that WODAM was applied to oil well cement. This paper prepared a new self-healing agent, and is of great significance to realize self-healing cement in complex downhole condition.     

An unusual superhydrophilic/superoleophobic sponge for oil--water separation

Development of porous materials with anti-fouling and remote control- lability is highly desired for oil–water separation application yet still challenging. Herein, to address this challenge, a sponge with unusual superhydrophilicity/superoleophobicity and magnetic property was fabricated through a dip-coating process. To exploit its superhydrophilic/superoleophobic property, the obtained sponge was used as a reusable water sorbent scaffold to collect water from bulk oils without absorbing any oil. Owing to its magnetic property, the sponge was manipulated remotely by a magnet without touching it directly during the whole water collection process, which could potentially lower the cost of the water collection process. Apart from acting as a water-absorbing material, the sponge can also be used as affiliation material to separate water from oil–water mixture and oil in water emulsion selectively, when fixed into a cone funnel. This research provides a key addition to the field of oil–water separation materials.     

天然生物质材料吸油性能研究

采用小麦秸秆、玉米秸秆、锯末、中药渣作为吸油材料,重点研究了吸附材料粒径、吸附时间以及不同油品对这4种天然生物质材料的吸油性能的影响。同时,研究对比了这4种材料的吸水性能和保油能力。在对原油进行吸附实验时,发现锯末和小麦秸秆在0.25～0.83mm粒径范围内具有较好的吸油性能,吸油量分别为5.79和6.02g/g,其次为玉米秸秆,0.15～0.18mm之间的材料吸油量最大能达到5.02g/g,而中药渣在0.18～0.20mm之间的吸油量仅为2.37g/g。比较4种材料对有机物甲苯及植物油的吸附性能发现,其对原油的吸附效果优于植物油和甲苯。材料均有一定的保油能力,而锯末的保油能力最高,其油水比>11。由于天然生物质材料属固体废物,其吸油后可直接作为燃料使用,可达到以废治废的目的,因此在含油污水处理领域具有较好的开发和应用前景。     

吸水膨胀材料的研究现状

吸水膨胀材料是一种新型高分子功能材料,具有吸水、膨胀变形特性,在建筑工程、油田开采、农林生产、医疗卫生等诸多领域已有广泛的应用。本文概述了吸水膨胀材料的发展历史、吸水膨胀机理,重点介绍了吸水膨胀材料的制备方法、改性方式,并就吸水膨胀材料的发展趋势进行了展望。     

Uptake and translocation of Cd in different rice cultivars and the relation with Cd accumulation in rice grain

The variations among six rice cultivars in cadmium (Cd) uptake and translocation were investigated with pot soil experiments. The results showed that only a very small portion (0.73%) of Cd absorbed by rice plant was transferred into grain. With regard to plant total Cd uptake, Cd concentrations and quantity accumulations in roots, stems and leaves, the differences among the cultivars (between the largest one and the smallest one) were less than one time. But for Cd concentrations and Cd quantity accumulations in the grains, the differences were more than five and eight times, respectively. With respect to Cd distribution portions in plant organs, the diversities among the cultivars were also small in roots, stems and leaves, but much larger in grains. Grain Cd concentrations correlated positively and significantly (P<0.01) with Cd quantity accumulations in plant, Cd distribution ratios to aboveground parts, and especially with Cd distribution ratios from aboveground parts to the grain. The results indicated that Cd concentration in rice grain was governed somewhat by plant Cd uptake and the transport of Cd from root to shoot, and in a greater extent, by the transport of Cd from shoot to grain. Cd was not distributed evenly in different products after rice grain processing. The average Cd concentration in cortex (embryo) was five times more than that in chaff and polished rice. With regard to Cd quantity accumulation in the products, near 40% in cortex (embryo), 45% in polished rice and 15% in chaff averagely.     

双连续相微乳液聚合制备多孔材料

反相(W/O)或双连续相微乳液聚合制备多孔材料是近年研究的热点。研究了双连续相微乳液聚合制备多孔吸油材料:以甲基丙烯酸甲酯、甲基丙烯酸丁酯为共聚单体(油相),水/乙醇为混合水相,偶氮二异丁腈为引发剂,十二烷基硫酸钠为乳化剂,调节油相和水相比例,配制出双连续相微乳液。聚合在无搅拌下进行。对聚合物进行SEM观测表明,当混合水相含量在30%～43%(质量分数,下同)区域内,得到连续开孔材料。仅对多孔材料制备工艺进行研究分析及孔特性进行了表征,吸油材料的研究将在后续文章中报道。