Magnetically Controlled Carbonate Nanocomposite with Ciprofloxacin for Biofilm Eradication

Biofilms are the reason for a vast majority of chronic inflammation cases and most acute inflammation. The treatment of biofilms still is a complicated task due to the low efficiency of drug delivery and high resistivity of the involved bacteria to harmful factors. Here we describe a magnetically controlled nanocomposite with a stimuli-responsive release profile based on calcium carbonate and magnetite with an encapsulated antibiotic (ciprofloxacin) that can be used to solve this problem. The material magnetic properties allowed targeted delivery, accumulation, and penetration of the composite in the biofilm, as well as the rapid triggered release of the entrapped antibiotic. Under the influence of an RF magnetic field with a frequency of 210 kHz, the composite underwent a phase transition from vaterite into calcite and promoted the release of ciprofloxacin. The effectiveness of the composite was tested against formed biofilms of E. coli and S. aureus and showed a 71% reduction in E. coli biofilm biomass and an 85% reduction in S. aureus biofilms. The efficiency of the composite with entrapped ciprofloxacin was higher than for the free antibiotic in the same concentration, up to 72%. The developed composite is a promising material for the treatment of biofilm-associated inflammations.     

用左权超纯铁精矿粉制取ZHF100·280还原铁粉的性能

叙述了用左权超纯铁精矿粉制取ZHF1 0 0·2 80还原铁粉的结果。所制铁粉的共生金属元素含量低 ,总铁含量高 ,具有良好的物理工艺性能 ,压缩性大于6 8g/cm3,一次压制密度可达 7 0 g/cm3以上。充分利用左权磁铁矿资源 ,发展优质铁粉 ,具有重要意义     

A Novel Method for Enhanced Recovery of Lignin from Aqueous Process Streams

Abstract

This study demonstrates that acid precipitation of lignin in the presence of magnetite followed by an applied magnetic field provides a simple method for enhanced lignin recovery from an aqueous stream. The extraction procedure was shown to be sensitive to the relative charge of magnetite and solution pH. Under optimized conditions, 93 wt.% of the softwood lignin from a kraft cooking liquor could be recovered employing this novel separation approach.     

Characterization of stabilized porous magnetite core–shell nanogel composites based on crosslinked acrylamide/sodium acrylate copolymers

Stabilized and dispersed superparamagnetic porous nanogels based on sodium acrylate (AA‐Na) and acrylamide (AM) in a surfactant‐free aqueous system were synthesized via solution polymerization at room temperature. The formation of magnetite nanoparticles was confirmed and their properties characterized using Fourier transform infrared spectroscopy. Extensive characterization of the magnetic polymer particles using transmission electron microscopy (TEM), dynamic light scattering and zeta potential measurements revealed that Fe₃O₄ nanoparticles were incorporated into the shells of poly(AM/AA‐Na). The average particle size was 5–8 nm as determined from TEM. AM/AA‐Na nanoparticles with a diameter of about 11 nm were effectively assembled onto the negatively charged surface of the as‐synthesized Fe₃O₄ nanoparticles via electrostatic interaction. Crosslinked magnetite nanocomposites were prepared by in situ development of surface‐modified magnetite nanoparticles in an AM/AA‐Na hydrogel. Scanning electron microscopy was used to study the surface morphology of the prepared composites. The morphology, phase composition and crystallinity of the prepared nanocomposites were characterized. Atomic force microscopy and argon adsorption–desorption measurements of Fe₃O₄.AM/AA indicated that the architecture of the polymer network can be a hollow porous sphere or a solid phase, depending on the AA‐Na content. © 2013 Society of Chemical Industry     

Magnetite‐coated polystyrene hybrid microspheres prepared by miniemulsion polymerization

Hybrid microspheres with a polystyrene core coated with magnetite nanoparticles were prepared by miniemulsion polymerization. Acrylic acid was used as a comonomer to promote the anchoring of the magnetite nanoparticles onto the polymeric surface. The addition of a hydrophobic agent prevents effectively the monomer from diffusing into the aqueous phase. Magnetite was treated with a silane coupling agent in order to introduce some interactions with the polymers. The morphology and the structure of the hybrid microspheres were characterized using X‐ray diffraction, infrared spectroscopy, transmission electron microscopy and thermogravimetric analysis. The results show that the morphology of the hybrid microspheres was influenced by the concentrations of acrylic acid, hydrophobic agent and surfactant, and that the degree of coating can be tuned by changing these parameters. The miniemulsion polymerization technique is adaptable to the synthesis of magnetite‐coated polymer particles, and the synthesis can be scaled up. Copyright © 2008 Society of Chemical Industry     

攀枝花白马钒钛磁铁矿选矿新技术研究

为了提高白马铁矿铁、钛资源的综合利用率,降低生产成本,使企业效益最大化,分析了白马铁现在的选铁流程,指出了流程中存在的问题。进一步提出白马铁矿需要进行粗粒抛尾,并用ZCLA 选矿机进行了粗粒抛尾试验,可以抛出尾矿产率为20%～40%的合格尾矿,抛尾尾矿TiO2含量仅为1.5%左右,铁钛回收率为89%～94%。进行了“半自磨-ZCLA选矿机抛尾-选铁-强磁选流程”试验研究,试验结果表明,粗粒抛尾能大幅度降低生产成本,提高经济效益,并且有利于后续的选钛作业。     

基于磁铁矿粉提高小浮沉试验准确性的研究

针对小浮沉试验中大于重液密度的沉物容易随离心液损失影响实验结果的问题,采用添加磁铁矿粉的方法,有效提高了小浮沉试验的准确性。试验探究了磁铁矿粉添加量对不同灰分煤样小浮沉试验效果的影响规律。结果表明,磁铁矿粉的添加增加了悬浮液的粘度,避免了大于悬浮液密度级的沉物随离心液流失,且磁铁矿粉易回收,从而得到更为准确的加权灰分,该方法得到的浮沉试验中的各密度级产率也更为科学有效。     

惯性圆锥破碎机在极贫磁铁矿干选抛尾工艺流程中的应用

惯性圆锥破碎机结构独特,在国内矿山、冶金等行业中已经取得了广泛应用。本文结合工业应用实例,介绍惯性圆锥破碎机的性能和特点,结合磁选工艺对极贫磁铁矿进行干式预选抛尾,成功实现极贫磁铁矿的预选富集,大幅提高铁矿石品位,扩大了可选别的资源范围。     

某超贫钒钛磁铁矿选矿试验研究

对某超贫钒钛磁铁矿开展了选矿试验研究,在工艺矿物学研究的基础之上,采用预选和再磨弱磁选工艺,获得了铁精矿铁品位58.32%,回收率60.76%的试验指标。     

某细粒铁矿石磁选-选择性絮凝脱泥研究

对某细粒铁矿石开展了磁选-选择性絮凝脱泥试验研究。结果表明, 矿石中磁铁矿为中细粒嵌布, 赤铁矿为微细粒嵌布, 二者嵌连关系紧密; 采用磨矿-强磁选, 可脱除TFe品位7.57%、产率49.40%的尾矿; 将磁选精矿细磨至-0.037 mm粒级含量98.64%, 在矿浆pH值11.6、矿浆浓度34.6%、腐殖酸钠用量0.5 g/L条件下进行四段选择性絮凝脱泥, 可脱除TFe品位12.20%、作业产率31.20%的矿泥。通过磁选-选择性絮凝脱泥大幅提高了反浮选的入选品位、降低了矿石处理量。