利用造纸污泥制备木素基阳离子絮凝剂及其性能的研究

以造纸污泥中提取的木质素为原料,合成了木素基阳离子絮凝剂。研究了催化剂种类、反应物配料比、反应温度、反应时间等对合成产物脱色性能的影响,确定了较佳合成工艺条件为:引发剂K2S2O8用量为木质素磺酸钠质量的0.7%,活化时间1.5 min,木质素磺酸钠与单体质量比为1∶1.5,反应温度为70℃,反应时间1.5 h,采用红外光谱对产物结构进行了表征。产物对几种模拟染料废水具有良好的脱色性能,在酸性(pH1～2)条件下,脱色率均达84.4%以上。通过比较木质素与接枝产物的絮凝效果以及絮体的微观形貌,对其絮凝机理进行了初步探讨。     

Synthesis of a lignin-based surfactant through amination,sulfonation, and acylation

A simple and effective chemical method based on Mannich reaction, sulfonation, and acylation was adopted to anchor the hydrophilic sulfonic groups and lipophilic long carbon chains onto alkaline lignin. The obtained products were characterized by Fourier transform infrared spectroscopy (FTIR) and elemental analysis, and the surface activity was evaluated by interfacial tension, which was determined by a maximum bubble pressure method. The results demonstrated that the ASAL showed high surface activity in comparison to lignosulfonate and the interfacial tension reached 5.0 (10^?3?N?·?m^?1) when the mass fraction of ASAL was 5%, in agreement with the properties of good surfactants.**     

Preparation and Characterization of Novel Quaternized Cellulose Nanoparticles as Protein Carriers

Quaternized cellulose (QC) nanoparticles were prepared in distilled water by ionic crosslinking of QC with sodium tripolyphosphate (TPP) for the first time. BSA as a model protein drug was used to investigate the loading and release features of the nanoparticles. The results indicated that QC nanoparticles had high loading efficiency and capacity for BSA. The in vitro BSA release of the QC nanoparticles displayed a burst effect in the first 2 h and then a slow continuous release. Nanoparticles with a higher DS of QC showed a decrease in particle size, an increase in zeta potential, a higher loading efficiency and a slower drug‐release profile. These studies demonstrated that QC nanoparticles are potential protein carriers, and that their physicochemical properties and release profile could be easily adjusted.

     

CTA季铵化壳聚糖合成条件的优化及其结构表征

以3-氯-2-羟丙基三甲基氯化铵(CTA)为改性剂,在碱性条件下制备了水溶性壳聚糖季铵盐,并以该产物对Cr2O7^2-的絮凝去除率为基准优化了合成条件,用IR和^1H-NMR表征了产物结构。结果表明,优化的合成条件为：反应时间为10．0h,温度为65．0℃,mNaOH／mCTS=1．0,mCTA／mCTS=4．0。在此条件下合成的产物对Cr2O7^2-的最大去除率达94．39％,壳聚糖的季铵化反应主要发生于C2位的氨基上。     

Synthesis and dyeing performance of a novel polycarboxylic acid azo dye

A novel reactive polycarboxylic acid dye was synthesized by the reaction of polymaleic anhydride（PMA） with 3-methyl-1-（4- sulfonylphenyl）-4-（4-aminophenylazo）-2-pyrazoline-5-one.The structure of the novel dye was characterized by FTIR,UV-vis and ¹³C NMR spectra.The dyeing properties of dye on cotton were tested,and the novel dye possessed high fixation and good fastness.     

Characterization and stability of TiO2 nanoparticles in industrial dye stuff effluent

Stability studies were conducted in different solutions (deionized water (DI), NaCl, CaCl₂, and MgCl₂) at different pH. Agglomeration and zeta potential were influenced by ionic strength, type of electrolyte, and the presence of dye stuff. The Derjaguin–Landau–Verwey–Overbeek (DLVO) theory was used to analyze the stability and/or agglomeration of the nanoparticles in the different solutions. Repulsive or attractive forces stipulated by the DLVO theory were used to quantitatively discuss the results. The increase in ionic strength increased agglomeration which was linked to pH_pzc, as there were minimal electrostatic repulsions at the pzc, yet the attractive van der Waals forces were dominant. Addition of the dye stuff significantly decreased the agglomeration as the dye stuff changed the overall zeta potential of TiO₂ nanoparticles to negative across the entire pH which improved stability as there were particle–particle repulsions. Monovalent and divalent cations were compared and Ca²⁺ increased the mean diameter of nanoparticles as it effectively decreased the EDL of the nanoparticles, thus enhancing agglomeration. The DLVO theory was successful at explaining, in terms of the interaction energies between nanoparticles, the phenomena that caused either agglomeration or stability of the as-synthesized TiO₂ nanoparticles in the different solutions.     

Synthesis of a 3-D porous Tb-MOF: organic dye adsorption

A 3-D lanthanide metal–organic framework, [Tb₂(L)_1.5(DMF)₂]·2DMF (1) (L = 14-diylbis(acylamino-21-diyl))-diisophthalic acid), has been synthesized under solvothermal conditions. 1 was characterized by X-ray single-crystal analysis and powder X-ray diffraction. The 3-D framework of 1 is constructed by 2-D channels embedded in a plane. Network analysis reveals that 1 is a (4,5,6,6)-connected net with stoichiometry (4-c)₂(5-c)₂(6-c)₃. As expected, this terbium(III) metal–organic framework exhibits good properties for adsorbing organic dye molecules due to its NH- group. It shows good adsorption selectivity for rhodamine B (RB) rather than methyl orange (MO) and methylene blue (MB) molecules.     

Grafting of hydroxymethylacrylamide and acrylic acid copolymer onto polyvinylidene fluoride membrane by supercritical carbon dioxide and its application in dye separation

We report a thermally induced graft copolymerization of acrylic acid and N‐hydroxymethylacrylamide onto polyvinylidene fluoride microporous membrane by using supercritical carbon dioxide as a solvent and carrier agent. The effects of monomer mole ratio, pressure, reaction temperature, time, and initiator concentration on the degree of grafting were investigated. The morphology of the grafted membrane was studied via scanning electron microscopy. Attenuated total reflectance infrared spectroscopy spectroscopy and X‐ray diffraction proved the existence of grafting monomers. The results of contact angle measurement and water filtration at different pH levels indicated pronounced pH‐sensitive behavior and increased hydrophilicity of the polyvinylidene fluoride grafted membrane. In particular, the grafted membrane was applied to the removal of methylene blue with a relative rejection of 98.1% compared with 30.5% of rejection observed from the pristine polyvinylidene fluoride membrane. Copyright © 2014 John Wiley & Sons, Ltd.     

Hollow porous organic polymer: High‐performance adsorption for organic dye in aqueous solution

Several hollow porous organic polymers were conveniently fabricated by poly‐condensation of tetraphenyl porphyrin (TPP), tetrabiphenyl porphyrin (TBPP), or triphenylbenzene (TPB), with nano‐sized ZnO particles as template and AlCl₃ as catalyst. The hollow polymers exhibit much enhanced adsorption capacity for organic dyes in aqueous solution relative to the pristine polymers. Particularly, the hollow polymer based on TBPP (h‐COP‐P) displays high adsorption capacity (460 mg/g within 500 min) as well as good recycling performance toward Rhodamine B. This capacity is about three times larger than that of corresponding pristine POPs (COP‐P) and is even comparable with the best performed organic polymers reports to date, which is ascribed to its unique hydrophobic hollow structure. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1329–1337     

Characterization,DFT calculations and dyeing performance on polyester fabrics of some azo disperse dyes containing pyrazole ring

A number of azo pyrazole derivatives and novel Schiff bases derived from azo diamino pyrazole were synthesized. These included 4-(2-arylhydrazono)-4H-pyrazole-3,5-diamines and N³,N⁵-dibenzylidene-4-(2-arylhydrazono)-4H-pyrazole-3,5-diamines. The chemical structures of the novel azo dyes were determined using UV–visible, IR, ¹H NMR, and ¹³C NMR spectroscopy. Dyeing process and tautomerism of the aforementioned azo compounds were predicted using DFT calculations. The electronic absorption spectra in methanol were observed and compared to those computed using B3LYP/6-31G(d,p). The dyeing performance of the produced disperse dyes was examined on polyester. The degree of exhaustion and the fastness properties of the dyed samples in terms of washing, perspiration, scorch, and light fastness were assessed. Moreover, the reflectance and color strength of the synthesized dyes were measured and discussed.     

Further Example of Diphosphates: Synthesis and Characterization of K2Li2P2O7

By the application of cation substitution, a new mixed‐alkali metal diphosphate, K₂Li₂P₂O₇, was successfully synthesized through high temperature solution method for the first time. The single‐crystal X‐ray structural analysis shows that it crystallizes in the monoclinic space group C2/c (no. 15), with lattice constants a = 9.814(3) Å, b = 5.5163(15) Å, c = 13.538(4) Å, Z = 4, and β = 110.47(2)°. Its open cage‐like _∞³[Li₂(P₂O₇)]^2– framework is built up from alternating arrangement of Li₂O₆ and P₂O₇ dimers that form eight and twelve‐membered‐ring channels along the [010] direction, and the K atoms are entrapped in the larger twelve‐membered‐ring channels. Detailed structure comparisons in the N₄P₂O₇ (N = mixed alkali metals) family are discussed. In addition, the structural validity was verified through the IR spectrum. Thermal analyses and UV/Vis/NIR diffuse reflectance spectrum are also performed on the reported compound.     

Silver ferrite–graphene nanocomposite and its good photocatalytic performance in air and visible light for organic dye removal

Silver ferrite–graphene (AgFeO₂‐G) as a nanocomposite photocatalyst shows potent visible‐light photocatalytic activity for the degradation of organic contaminants, and generates the strong oxidants hydroxyl radical (^•OH) and superoxide anion radical (O₂^•−) via photoelectrochemical decomposition of H₂O and O₂ in the presence of air and visible light irradiation. The photogenerated electrons of AgFeO₂ can transfer easily from the conduction band to the reduced graphene oxide, efficiently preventing the direct recombination of electrons and holes. As a matter of fact, AgFeO₂ has a low bandgap. Furthermore, AgFeO₂ nanoparticles themselves have a magnetic property, which makes them magnetically separable. The experimental results show that the graphene nanosheets in the nanocomposite catalyst are exfoliated and decorated homogeneously with AgFeO₂ nanoparticles. The photodegradation occurs in a short time (ca 40 min). Also, the photocatalytic activity of the nanocomposite does not show any clear loss after ten recycles of the degradation process.     

An octupolar near-IR dye with triphenylamine donors: preparation and absorption properties

A topologically new NIR dye based on a carbocation centered octupole and conjugated triphenylamine donors is described. The dye produced an absorption maximum at 954 nm and by virtue of its two degenerate NBMO-LUMO transitions, showed a large molar extinction coefficient (log ε 4.9).     

Role of polymer network and gelation kinetics on the mechanical properties and adsorption capacity of chitosan hydrogels for dye removal

Chitosan (CS) hydrogels are receiving growing attention as adsorbents for water purification purposes. The conditions of preparation of this class of materials play a crucial in the determination of their performances; however, this aspect is often neglected in the literature. In this study, we deal with this issue, focusing on the structure‐property relationships of CS hydrogels obtained by phase inversion method. We show that the concentration of the starting solution determines the density and strength of intermolecular interactions, and that the gelation kinetics dictates the hydrogel structure at the microscale. Consequently, even subtle changes in the preparation protocol can cause significant differences in the performances of CS hydrogels in terms of mechanical properties and dye adsorption capacity. The observed trends are often neither trivial nor monotonic. Nonetheless, we demonstrate that they can be interpreted looking at the CS network structure, which can be inferred by rheological measurements. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 1843–1849     

Alkali‐Metal ortho‐Hydroxyphenolates: Syntheses and Crystal Structures from Powder X‐Ray Diffraction

Colorless and highly air‐ and moisture‐sensitive powders of M[o‐C₆H₄O(OH)] with M = K, Rb, or Cs have been synthesized from reaction mixtures of the appropriate alkali metal and catechol in thf. All compounds were structurally characterized by means of powder X‐ray diffraction using the Rietveld profile refinement technique including restraints for the C—C/C—O bond distances and the C—C—C angles. The atomic arrangements of M[o‐C₆H₄O(OH)] (K: monoclinic P2₁/c; Rb/Cs: orthorhombic Pbcm) are characterized by polymeric chains of [M₁^[4]O₂^[2]η⁶] units connected by hydrogen bonds, thereby making up layered structures similar to the one of catechol. The coordinatively unsaturated alkali metals are forming edge‐sharing MO₄ pyramids and exhibit asymmetrical η⁶‐interactions with the phenylene rings. The symmetry of the unit cells increases with increasing size of the cation, and this results in a decrease of the monoclinic angle from 118.5° (catechol) to 93.7° (K compound), eventually leading to orthorhombic cells for the Rb and Cs compounds.     

Characterization and filtration performance of coating-modified polymeric membranes used in membrane bioreactors

One of the critical issues for membrane application in wastewater treatment is membrane fouling majorly caused by dissolved organic matters. The aim of the present study was to lower membrane fouling by adsorption of polyelectrolytes. In the paper, the feasibility of coating for diverse ultrafiltration membrane materials was investigated and their filtration performance was compared to that of the unmodified ones. Different ultrafiltration flat-sheet membranes, polyvinylidene fluoride, polyethersulfone, polysulfone and cellulose acetate were coated by branched poly(ethyleneimine) (PEI), poly(diallyldimethylammonium chloride) (PDADMAC) and poly(allylamine chloride) (PAH) and filtrated with sludge supernatant. Short term experiments showed a substantial drop of permeability: almost 40 % for PEI, 23 % for PDADMAC, and about 19 % for PAH coating. This deterioration resulted from the additional resistance of the deposited layers. On the other hand, coating led to lower fouling rates during filtration. In the stable state of filtration, coated membranes showed higher permeabilities compared to the uncoated ones. For the polyethersulfone membrane, the average permeability enhancement was 11 %. For polysulfone and cellulose acetate membranes, the permeability improved by 28 % and 15 % respectively. For polyvinylidene fluoride membranes only coating with PDADMAC enhanced the permeability, by 13 %. PEI and PAH modified membranes featured lower permeabilities than the uncoated ones. Presented at the 35th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 26–30 May 2008.     

胰岛素的mPEG修饰及其活性表征

用单甲氧基聚乙二醇-丙醛(mPEG-ALD)、单甲氧基聚乙二醇-丁醛(mPEG-ButyrALD)和单甲氧基聚乙二醇-琥珀酰亚胺碳酸酯(mPEG-SC)对猪胰岛素进行化学修饰. 考察了反应时间、pH、物质的量比及分子量等因素对修饰效果的影响. 通过HPLC, MALDI-TOF-MS(基质辅助激光解吸时间飞行质谱), SDS-PAGE(十二烷基硫酸钠-聚丙烯酰胺凝胶电泳)和TNBS(三硝基苯磺酸钠法)等表征发现mPEG-ButyrALD具有更高的修饰选择性和修饰率. 圆二色光谱(CD)分析修饰产物的二级结构发现, 胰岛素经mPEG衍生物修饰后, 二级结构基本没有改变. 动物实验表明, mPEG-ButyrALD修饰胰岛素后半衰期延长, 因而可以延长降血糖作用时间, 改善胰岛素药效.     

Manufacture of activated carbons using Egyptian wood resources and its application in oligothiophene dye adsorption

The following paper presents research on the conversion of wood wastes accessible in Egypt into activated carbon. In this study, wood samples of four Egyptian tree species were used: Delonix regia, Leucaena leucocephala, Salix mucronata, and Tipuana tipu. The wood scraps were soaked in a KOH solution and then carbonized at 600 °C under the flow of nitrogen; the resulting materials were analyzed by means of microscopic and spectroscopic techniques, low-temperature adsorption of nitrogen, and an investigation of the surface area using nitrogen sorption. The addition of a chemical activator facilitated an increase of the surface area up to 603 m² g⁻¹. In its second part, the work aims to experimentally confirm that synthesizing hybrid materials consisting of oligothiophene dye (OT) and the obtained activated carbon may contribute to improving the applicability of these carbons as dye adsorbents. Confocal microscopy, Raman spectra, and SEM-EDX microscopy were used to confirm the immobilization of oligomers on the surface of carbon hybrid materials. Confocal microscopy in particular is considered to be an appropriate technique of detecting the presence of adsorbed 6 T molecules on the carbon surface. The presented research is a major step towards the application of modified carbons as an attractive and inexpensive base for dye molecule adsorption.     

Anaerobic biological treatment of dye bearing water in anaerobic sequencing batch reactor: Performance and kinetics studies

Textile and dye industries are main sources of dye bearing effluent. In present studies the anaerobic biological degradation of Acid Red 3BN dye water (AR3BNDW) and mixed dye water (MDW) for reduction of color and COD were studied in sequential batch reactor (SBR). The sludge as sources of microorganism was arranged from maize processing bio methanation wastewater treatment plant, which was acclimatized for treatment of AR3BNDW and MDW. After the acclimatization, dyes degradation were studied in SBR At optimum operation condition of hydraulics retention time (HRT) = 2.5 d, and treatment time (t_R) = 16 h, AR3BNDW have gone maximum 87% color reduction of 500 mg/L dye, and 82.8% COD reduction of 380 mg/L COD. At same operating condition, 84.5% color reduction of 500 mg/L dye, and 79.42% COD reduction of 413 mg/L COD achieved for MDW. The second order Grau model was fitted well for COD and dye reductions. The kinetics parameter were evaluated for both the dye water.