Alum-Catalyzed Domino Synthesis of 12-Substituted-8,9,10,12-tetrahydrobenzoxanthen-11-ones Under Solvent-Free Conditions

Alum is found to catalyze efficiently the one-pot, three-component condensation of aldehydes, α/β-naphthol, and dimedone to afford various 12-substituted-8,9,10,12-tetrahydrobenzoxanthen-11-ones in excellent yields. The use of alum catalyst and the solvent-free conditions make this method simple, convenient, eco-friendly, and cost-effective.     

Coagulation-crossflow microfiltration of domestic wastewater

The effect of using alum, polyaluminum silicate sulfate (PASS), and lime as coagulants on the performance of crossflow microfiltration of domestic wastewater was investigated. The primary membrane used throughout the study was made of woven polyester, while the dynamic membrane was formed by circulating MnO₂ precipitate. Slug doses of the coagulants were added to the circulation tank of the experimental setup at the beginning of each run. Doses of 20 to 120 mg/l of alum were investigated at pH of 7. The results showed an improvement in flux values with the increase in alum dose until an optimum dose beyond which no significant improvement was seen. Flux improvement was attributed to the agglomeration of particles which can be easily swept away by the shearing actions created by the crossflow velocity. Permeate quality was not found to be significantly affected by the increase in alum dose. PASS, which is an aluminum salt, was seen to behave in the same manner as alum when used as a coagulant. Lime was not found to be a suitable coagulant under these conditions.     

明矾炮制前后半夏中铝形态分析

通过中药传统煎煮和超声提取两种方法获取生半夏和清半夏水提液,采用下列三步分析水提液中各种铝形态:用0.45μm微孔滤膜过滤,部分滤液通过732Na型阳离子交换树脂,另一部分滤液与8-羟基喹啉反应.石墨炉原子吸收光谱法测定总铝及各形态铝含量.结果显示,生半夏中铝总量11.20μg/g,清半夏则高达3.253mg/g.生半...     

Alum (KAl(SO4)2 · 12H2O): An Efficient and Inexpensive Catalyst for the One-pot Synthesis of 1,3,4-Oxadiazoles under Solvent-Free Conditions

Summary. Alum (KAl(SO₄)₂ · 12H₂O) catalyzed the efficient synthesis of mono- and disubstituted 1,3,4-oxadiazoles by the condensation of acyl hydrazides with orthoesters under solvent-free conditions at 100°C. This methodology offers significant improvements for the synthesis of oxadiazoles with regard to the yield of products, simplicity in operation, inexpensive reagents, and green aspects by avoiding toxic catalysts and solvents.     

KAl(SO4)2 · 12H2O as a Recyclable Lewis Acid Catalyst for Synthesis of Spirooxindoles in Aqueous Media

A simple and efficient procedure for the synthesis of spirooxindole has been described that employs a three-component condensation reaction in one pot using isatin, active methylene reagent, and 1,3-dicarbonyl compounds in an aqueous medium.     

KAl（SO4）2·12H2O catalyzed efficient synthesis of 3,4,6-trisubstituted 2-pyridone in water

An efficient green protocol for the preparation 3,4,6-trisubstituted 2-pyridone of employing a condensation reaction of cyanoacetamide and acetylacetone in the presence of KAl（SO₄）₂·12H₂O in water has been described.The present procedure offers advantage such as shorter reaction time,simple workup,and excellent yields.     

Novel UV-protective formulations for cotton, PET fabrics and their blend utilizing irradiation technique

A novel coating formulation to impart ultraviolet (UV) protection property to cotton, Polyethylene trephethalate (PET) and cotton/PET fabrics was prepared and gamma rays as an ionizing radiation was utilized for surface curing. Natural occurring aluminum potassium sulfate (Alum) was used individually and in binary coat with Zinc Oxide (ZnO), to induce the UV-blocking properties. It was found that using Alum (0.3 g/ml) caused a prompt increase in ultraviolet protection factor (UPF) over the uncoated fabrics. Moreover, the incorporated ZnO in the binary coat increased the UPF for two to threefold than the stand-alone Alum coating, specially in case of PET coated fabric. Water absorbance and moisture regain of ZnO and Alum/ZnO coated fabrics showed a decrease over the blank samples, due to the usage of oligomer/monomer combination. On contrary, Alum showed a hydrophilic effect with the increase in its content in the formulation. Surface Electron Microscope showed the homogenous coating of fibers. X-ray diffraction (XRD), energy dispersive X-ray (EDX) and water vapor permeability were also tested for coated samples.     

改性明矾浆和滤食性动物控制月湖的蓝藻水华

2000年初夏宁波月湖发生大面积蓝藻水华。同年8月1m^2水面喷洒55．6g改性明矾浆应急除藻后,蓝藻水华基本消失。2000年底和2001年初,1 hm^2水面放养尾均重25．6g鲢、鳙鱼种3500尾和平均体长7．5cm的三角帆蚌蚌种6700尾。2001和2002年不再出现蓝藻水华,水体表观质量明显提高,透明度保持在100cm以上。2001年8月份月湖浮游蓝藻数量比2000年同期下降87．5％,总氮下降26．0％,总磷下降70．0％。     

Clay and oxide destabilization induced by mixed alum/macromolecular flocculation aids

The review points out typical differences and analogies of the bulk characteristics of aluminum ion complexed polyelectrolytes and of their adsorption behaviors when such systems were supplied to inorganic colloids such as oxides and clays. It reports some particular investigations that were carried out in aqueous media to determine (i) the nature of the interactions existing between clay or oxides, aluminum ions and polyelectrolytes and (ii) the effects on the interfacial characteristics and the colloid stability related to the relative concentrations of these different constituents. The investigations concerned the synthetic alumina/polyacrylic acid systems and the natural kaolinite/humic acid systems, as well as partly the mixed alumina/humic acid systems. Different adsorption features and destabilization kinetics were determined to develop within these systems. One of the main constraints of the investigation arose from the presence of three interacting components which developed amphoteric and amphipatic interactions, the latter being generated by the hydrophobic moieties induced by the aluminum ions/carboxylic acid groups ion-pairing. The investigations concerned the extent and the rate of transfer of hydrogen, aluminum ions and polyelectrolytes from the bulk solution to the solid surface. Electrical surface charge characteristics were expressed in terms of the ζ potential of the colloid/polymer complexes. The colloid stability of the systems was determined as a function of time at short and long terms. The variation as a function of time of the number and weight average masses was correlated with the variation with time of the ζ potential. All these systems were determined to reach the kinetic and thermodynamic equilibrium only slowly. Despite the fact that the supply of mixed coagulants provoked the initial aggregation and the subsequent fragmentation processes for both systems, the mechanisms responsible for the two processes were found to be different as revealed by comparatively investigating the synthetic and the natural systems. The fragmentation originated from the slow segregation process of positively and negatively charged groups for the natural kaolinite/humic acid systems, while the segregation process affected hydrophobic and hydrophilic moieties for the synthetic alumina/polyacrylic acid systems.     

An Efficient One‐Pot Four‐Component Synthesis of Some New Spirooxindole Dihydropyridine Using Alum as a Heterogeneous Green Catalyst

4‐Nitro‐2,3‐dihydrospiro[imidazo[1,2‐a ]indeno[2,1‐e ]pyridine‐5,3′‐indoline]‐2′,6(1H )‐dione derivatives have been synthesized in good yields in a one‐pot four‐component, and efficient process by reaction of corresponding isatins, 1,3‐indandione, diamine, and nitro ketene dithioacetal in the presence of KAl(SO₄)₂.12H₂O (Alum) as a nontoxic and easily available heterogeneous green catalyst.