Ultrafine nano-silica, with its smaller particle size compared to conventional nano-silica, is typically synthesized via gas-phase methods that require complex raw materials and processes. Here, we report optimized conditions for preparing ultrafine nano-silica via a precipitation reaction between fluosilicic acid waste and aluminum hydroxide. The optimal conditions determined were as follows: reverse feeding, surfactant addition at 3.0%, aluminum-to-silicon ratio of 2.00, reaction time of 30 min, reaction temperature of 90 °C, and stirring rate of 250 rpm. Under these conditions, ultrafine nano-silica with a uniform particle size of approximately 11 nm was successfully synthesized. Characterization of samples prepared by different feeding methods showed that the reverse feeding method yielded ultrafine nano-silica with superior performance indicators compared to the forward feeding method. Analysis of system changes during synthesis indicated that the feeding method influenced the acidic or alkaline environment of the substrate, affecting SiF 4 hydrolysis and the subsequent dehydration and condensation of Si-(OH) 4 monomers, leading to variations in silica particle agglomeration. Further, an analysis of the effects of alkyl chains in surfactants on the surfaces of silica particles, including -OH substitution or Si-O-Si bond cleavage, provided insights into the action mechanism of surface groups on ultrafine nano-silica particles.

Calcium carbonate (CaCO3) whiskers are promising materials for the high-value utilization of calcium-based resources. Here, aragonite whiskers were synthesized at a carbonation temperature of 90 °C using carbide slag ammonium leachate as the calcium source and CO2 as the precipitant. The effects of control agents, carbonation temperature, Ca2+ solution feeding rate, CO2 flow rate, and stirring speed on whisker morphology and aspect ratio were systematically investigated. Characterization via SEM and XRD revealed that the optimal conditions—carbonation temperature of 90 °C, Ca2+ feeding rate of 1.2 mL∙min−1, ethanol addition of 2 mL, CO2 flow rate of 150 mL∙min−1, and stirring speed of 300 rpm—yielded uniform CaCO3 whiskers with an average length of ~10 μm, an aspect ratio of ~24, and an aragonite purity of 99.42%. TEM confirmed that the whiskers are single crystals growing preferentially along the [001] direction. Hydroxyl groups were found to suppress lateral growth on the (200) facet, favoring elongation along the c-axis and enabling high-aspect-ratio whisker formation. These findings provide useful guidance for the scalable synthesis and industrial application of aragonite whiskers.

The synergistic flame retardancy of PC/ABS alloy is investigated using TiO2 coated by microcapsulated red phosphorus(TDP)as the main flame retardant,which is produced in situ by tetrabutyl titanate hydrolysis reaction.Taking the LOI value and UL-94 grade of PC/ABS composite as the main index,TDP-based ternary synergistic system with mass ratio of TDP∶ZnO∶DOPO=16∶4∶5 is determined as the most suitable flame retardant.Characterization of combustion characteristics,flame retardancy,and mechanical properties indicate that with the increase of the addition of flame retardant TDP/ZnO/DOPO,the combustion characteristics,such as TTI,PHRR,THR,AEHC,peak CO2 release value,etc,decrease,while the bending strength and tensile strength decrease slightly,particularly,the flame retardancy(LOI value,UL-94 grade)increase.Considering this,5%(mass fraction)is determined as the most suitable addition of ternary synergistic composite flame retardant,under which the LOI value of the PC/ABS composite reach to 28.6%with UL-94 grade of V-0.The TTI,PHRR,THR,AEHC,and peak values of CO2 emission decrease by 27.27%,21.62%,22.10%,5.95%,and 25.97%,respectively,while the tensile strength and bending strength of the composite decrease by only 19.65%and 13.26%,respectively.The preliminary discussion on the affection mechanism of the ternary synergistic system to PC/ABS alloy suggests that the flame retardancy is attributed to the synergistic action of the gas phase flame-retardant mechanism of DOPO and the condensed phase flame-retardant mechanism of TDP and ZnO.

Layered double hydroxide (LDH) is a widely used flame retardant in polymer materials; however, the poor dispersion due to its high hydrophilic nature results in disappointing thermal stability and fire safety. In this work, LDH was in-situ grown on the disordered montmorillonite (MMT) nanosheets to obtain the hybrid of LDH and MMT nanosheets (LDH@MMT, simplified as LM). Various techniques, including X-ray diffraction, Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, and transmission electron microscope were used to characterize the microstructure of LM. In addition, the acrylonitrile-butadiene-styrene (ABS) composite containing LM and intumescent flame retardant (IFR) was prepared, and its mechanical and flame-retardant properties were also measured. The characterization results demonstrate that the LM exhibits a periodically alternating layered structure. The Limiting Oxygen Index (LOI) of the ABS composite reaches 27.2% with a V-0 rating in the UL-94 vertical burning test, while its flexural strength and tensile strength decrease by only 17.82% and 13.45%, respectively. Furthermore, the heat release rate, total heat release, smoke production rate, and carbon monoxide production rate of the ABS composite present a significant decline in cone calorimeter tests compared with those of pure ABS. The results further indicate that the hybridization could effectively improve the flame-retardant performance of ABS composites and perform lesser impacts on their mechanical properties.

Using dolomite calcined powder as raw material,the Ca and Mg elements were separated by ammonium leaching method,and then high-purity nano-MgO was prepared by carbonization method,and the more suitable process conditions for carbonization reaction,heavy magnesium water pyrolysis,basic magnesium carbonate calcination and other processes were investigated and determined as follows:carbonization reaction process:carbonization endpoint pH value of 7.5,CO2 flow rate of 0.4 L/min,reaction temperature of 15℃,stirring rate of 400 r/min;Under these conditions,the conversion rate of MgO could reach 87.79%.Mg(HCO3)2 solution pyrolysis process:pyrolysis temperature of 95℃,pyrolysis time of 40 min;Under these conditions,the pyrolysis rate of Mg(HCO3)2 solution reached 94.46%,and the pyrolysis intermediate product was monoclinic 4MgCO3·Mg(OH)2·4H2O.4MgCO3·Mg(OH)2·4H2O calcination process:calcination temperature of 700℃,calcination time of 1 h.Under the above optimization conditions,the MgO content of the prepared MgO sample reached 99.11%,and the XRD and FE-SEM characterization of the sample showed that the prepared MgO sample was a cubic crystalline nano-MgO with a particle size of about 30 nm.

通过共沉淀法和离子交换法成功制备出不同阴离子插层水滑石(layered double hydroxides,LDHs)并比较吸附性能,筛选出性能最佳的乙酸根插层的Mg2Al-LDHs.考察乙酸根插层的Mg2Al-LDHs吸附磷过程的吸附动力学、吸附热力学,通过X-射线衍射仪(XRD)、傅立叶红外变换光谱仪(FTIR)对CO32--Mg2Al-LDHs前驱体、Ac--Mg2Al-LDHs 2种吸附剂吸附前、后样品进行表征.结果表明:Ac--Mg2Al-LDHs对磷吸附过程符合准二级动力学模型和Langmuir等温热力学模型,属于自发吸热的单分子层吸附过程.由于CO32--Mg2Al-LDHs层间碳酸根离子与层板结合过于紧密,磷酸根离子无法将碳酸根离子置换,因此CO32--Mg2Al-LDHs以表面吸附为主;相较于CO32--Mg2Al-LDHs,Ac--Mg2Al-LDHs样品吸附过程中发生表面吸附和化学吸附,故吸附性能提升明显.

采用"层层自组装法"制备了水滑石/蒙脱石(LDH/MMT)复合物,并以FT-IR、XRD和FESEM等对其进行了结构和形貌分析.以印染废水中甲基橙(MO)为目标污染物,考察了 LDH/MMT复合物对甲基橙的吸附性能,结果表明:LDH/MMT吸附甲基橙过程的平衡吸附量可达到372.70mg/g,优于LDH和MMT.吸附动力学、热力学研究表明吸附过程符合准二级动力学模型和Langmuir等温吸附模型,属于自发、放热的单分子层吸附过程.采用FT-IR和XPS对吸附机理进行初步探究,认为吸附是由于复合物中的金属离子和甲基橙中-OSO3-基团之间的络合,甲基橙进入层间发生离子交换以及复合物表面羟基和甲基橙中苯环形成OH-π键等的共同作用.

为克服阻燃剂在聚合物基体中的分散性和相容性较差等问题,采用三氧化二锑(AT)粉末对水滑石(LDH)进行改性,并对改性LDH进行表征.将AT/LDH和四溴双酚A(TBBPA)掺入ABS制备复合材料,并研究不同配方对复合材料的阻燃性能和力学性能的影响.结果表明:AT的加入不改变LDH的层状结构.AT/LDH在高温下表现较好的热稳定性.改性LDH克服阻燃剂团聚的趋势.当m(AT):m(TBBPA)为1:6,m(AT):m(LDH)为15％,ABS复合材料的极限氧指数(LOI)达到29.5％,垂直燃烧测试达到V-0级,而弯曲强度和拉伸强度与纯ABS相比分别下降36.38％和20.40％.

Efficient catalysts for oxygen (O2) activation under room condition are required for effective wet air oxidation (WAO) technology. Here, we report a novel manganese-cobalt-based composite (MnO-CoO@Co) fabricated on a graphite felt (GF) support for catalyzing the electro-activation of O2 under room condition. Abundant Co-MnO and CoO-MnO heterointerfaces are formed in the composite. In comparison to the single-metal counterparts, i.e. CoO@Co/GF (16.99 wt% Co) and MnO/GF (26.83 wt% Mn), the bimetal MnO-CoO@Co/GF (5.29 wt% Co and 8.79 wt% Mn) displays an improved oxygen storage capacity and provides more active sites to accommodate surface adsorbed oxygen species. Notably, the strong synergy derived from bimetal heterointerfaces enhances the electron transfer and oxygen mobilization during the electro-activation of O2, thereby significantly reducing the reaction barrier. MnO-CoO@Co/GF exhibits excellent efficiency and stability in electrocatalytic WAO (ECWAO) towards the removal of pharmaceuticals and personal care products (PPCPs) over a wide pH range from 4.0 to 10.0. A model pollutant sulfamethoxazole (SMX) acquires mineralization efficiency of 78.4 ± 2.1% and mineralization current efficiency of 157.89% at +1.0 V of electrode potential. The toxicity of PPCPs can be totally eliminated after the ECWAO treatment. This work highlights the synergy derived from bimetal heterointerfaces in O2 electrocatalysis, and provides a promising approach for advanced WAO catalysts in PPCPs pollution control.

以甲酰胺和去离子水为抑制剂,采用一步合成—再分散法合成了ZnMgAl三元类水滑石超薄纳米片(n-t-HTLC).表征结果显示,n-t-HTLC具有宽化的水滑石类化合物(003)XRD特征峰,在z轴生长方向上的层状有序结构被破坏,呈六边形片状形貌,横向尺寸100～200 nm,厚度集中于约2 nm,比表面积为80.397 m2/g.n-t-HTLC具有优良的氯离子吸附性能,饱和吸附量为53.291 mg/g,吸附脱除溶液中氯离子的过程符合Langmuir等温吸附模型和准二级吸附动力学模型.Zeta电位测试结果表明,溶液中的氯离子除以静电作用方式发生物理吸附外,还以共价结合的方式化学吸附于"剥离"后板层的外表面和内层结构中.

利用反向微乳液法制备了十二烷基硫酸钠插层锌铝水滑石,并用扫描电子显微镜、X射线衍射仪对样品进行表征.探究了接触时间、温度、pH对于十二烷基硫酸钠插层锌铝水滑石吸附水中Cu2+的影响.结果表明:十二烷基硫酸钠插层锌铝水滑石对模拟废水中的Cu2+最大吸附量为64.10 mg/g.准二级吸附动力学模型和Langmuir模型可以很好地拟合该吸附剂对Cu2+的吸附过程.该吸附过程属于自发的吸热过程.实验证明:十二烷基硫酸钠插层锌铝水滑石对Cu2+有良好的吸附效果.

The difficult-to-remove CaSO4 scale layer attached to an evaporator wall is a major problem in related industries. How to efficiently remove the CaSO4 scale layer and convert it into fine chemicals with high added value, so as to turn waste into treasure, is a current research hotspot. In this study, a CaSO4 scale layer was removed by 15 min rotary washing via a phase transfer route. Further, using the eluted calcium gluconate solution as a raw material and polyethylene glycol as the crystal control agent, CaCO3 was prepared by a CO2 carbonization method. The preparation conditions of CaCO3 were optimized by single factor experiments, and the phase and morphology of the prepared samples were characterized by XRD and FESEM. The results show that the optimized conditions are as follows: reaction temperature 80 °C, reaction time 1 h, polyethylene glycol addition 3%, and a stirring rate of 400 rpm. The samples prepared under these conditions are pure-phase calcite-type CaCO3 microrods with lengths of 1-2 μm and diameters of 300-500 nm.

为充分利用白云石中的钙镁元素,利用柠檬酸钙的超溶解度特性,对柠檬酸铵溶液浸取白云石煅粉中钙元素工艺进行了研究.通过单因素条件实验和正交实验,重点考察并确定较适宜浸取反应工艺条件为:液固比20:1、n(TAC):n(CaO)=4:3、反应温度20℃、反应时间10 min,此条件下白云石煅粉中Ca2+、Mg2+浸取率分别为99.34％,6.11％.由柠檬酸钙碳化可制得ω(CaCO3)=98.2％,大小较均匀,长约2μm宽约0.6μm的纺锤状,方解石型轻质CaCO3;由滤饼经水化、碳化、热解、煅烧处理后,可制得ω(MgO)=99.2％,大小较均匀,长约4μm宽约0.5μm的短棒状MgO样品.

以聚磷酸铵(APP)为主体阻燃剂,有机改性蒙脱土K-10(OMMT)、磷酸三苯酯(TPP)为协效阻燃剂,以极限氧指数(LOI)为主要考察指标,构建APP基三元阻燃配方体系(OAT).采用熔融共混法制备聚碳酸酯(PC)/丙烯腈-丁二烯-苯乙烯共聚物(ABS)/OAT复合材料,采用热重分析、UL-94垂直燃烧测试、LOI测试、锥形量热测试等方式,研究PC/ABS/OAT复合材料的热稳定性和阻燃性能.结果表明:当m(OMMT):m(APP):m(TPP)=2:12:3,OAT具有良好的阻燃性能.相比PC/ABS合金,PC/ABS/30％OAT复合材料具有最优的热稳定性和燃烧残炭率,LOI值从19.8％升至28.5％,UL-94达到V-0等级.PC/ABS/30％OAT的热释放速率峰值(Pk-HRR)、总放热量(THR)、CO释放量和CO2释放量,与PC/ABS合金相比分别下降64.79％、26.68％、55.59％、81.44％.

以聚丙烯(PP)复合阻燃材料样条的极限氧指数(LOI)为主要考察指标,考察了类水滑石(LDHs)及其与焦磷酸哌嗪(PAPP)、次磷酸铝(AHP)等在不同质量比下复配添加对PP复合材料阻燃性能的影响.实验结果表明:当复配阻燃剂的添加量为40％,LDHs:PPAP:AHP质量比为3:1:1时,PP复合材料的LOI值由17.6％提高到28.6％,UL-94测试达到V-0级.添加了LDHs、PPAP、AHP的PP复合阻燃材料样条的弯曲和拉伸强度较单独添加LDHs时有所提高,力学性能得到明显改善.通过SEM分析和TG、DTG分析,初步认为不同质量比LDHs/PPAP/AHP的阻燃作用可简要概括为"协效成炭阻燃作用机制".LDHs/PPAP/AHP的协效添加,明显提高PP复合材料的残炭率,样条燃烧后生成较厚的膨胀残炭层,提高了PP复合材料的阻燃性能.

Electrocatalytic wet air oxidation (ECWAO) is a novel wet air oxidation technology using an anodic electric field to stimulate oxygen for catalytic oxidation of water pollutants at ambient condition. Herein, a mechanistic kinetic model is established based on the degradation of bisphenol A in an ECWAO process with manganese oxide (MnOx) catalysts, and the general applicability of the model is verified by triclosan degradation over a Ni@NiO catalyst and sulfamethoxazole degradation over a MnMoOx catalyst. Elementary steps involved in solid-catalyzed reaction and the assistant role of anodic electric field in the catalysis are taken into consideration. A group of kinetic equations based on the Langmuir-Hinshelwood-HougenWatson (LHHW) or Eley-Rideal (ER) rate laws are evaluated using the criteria of the minimization of the residual sum of squares and average error. The results show that the ECWAO reaction is best described by the LHHW model in which the surface reaction between adsorbed oxygen and adsorbed organic molecules is the rate-determining step. The key parameters controlling ECWAO reaction kinetics are the adsorption equilibrium constant of oxygen and rate constant of the surface reaction. According to the kinetic model, the reaction rates of organic pollutants are nearly linear dependent upon their concentrations within a certain range. With the increment of the circuit current, the reaction rates of organic pollutants first rise, then reach a plateau, and finally decline. The mechanistic kinetic model proves to be applicable for interpreting and predicting the ECWAO rates of organics over the transition metal oxide catalysts.

With the development of science and technology, people also pay more and more attention to the development of new energy. Although there are also many studies on integrated energy systems now, integrated energy systems containing energy storage should also be further studied. This paper proposes an optimization of integrated energy system for combined cooling, heating and power supply of new energy based on energy storage, which analyzes the gas turbine, absorption refrigerating machine, electric refrigerator, photovoltaic power generation units, wind turbine and the work characteristics of the energy storage device. In this paper, an integrated energy system optimization model of new energy cogeneration with energy storage equipment is established. An example shows that the integrated energy system with energy storage can effectively solve the independent decoupling operation relationship among cool, heat and electricity. At the same time, the proposed model can also solve the energy interaction among cool, heat and electricity. In this way, the optimal operation of the integrated energy system can be realized.

Abstract In this article, a powerful method to synthesize uniform CaCO3 rod bundles with a high mass fraction of aragonite from carbide slag in large‐scale production via a two‐step leaching‐precipitation process is reported. The effects of the addition of ethylene glycol and reaction temperature on the structure and morphology of the prepared CaCO3 samples were investigated and then demonstrated by the experimental results. It is beneficial to increase the mass fraction of aragonite in CaCO3 samples and ensure the formation of regular rod bundles in morphology when the addition of ethylene glycol is 30 mL and the reaction temperature is 80 °C. The formation mechanism of the CaCO3 rod bundles was preliminarily discussed according to the Muffins–Sekerka theory.

采用共沉淀法制备了镁铝层状双金属氢氧化物(MgAl-LDHs),再经焙烧制备了镁铝层状双金属氧化物(MgAl-LDO),采用FESEM、XRD进行了表征分析.考察了焙烧温度、吸附剂投加量等对MgAl-LDO吸附脱除模拟废水中Cr(Ⅵ)性能的影响.结果表明,在优化条件下吸附量可达到95.60 mg·g-1.对吸附了Cr(Ⅵ)的MgAl-LDO样品进行表征,结果表明,"结构记忆"效应对Cr(Ⅵ)的脱除起主要作用;吸附过程的等温吸附模型研究表明,MgAl-LDO对模拟废水中Cr(Ⅵ)的等温吸附行为符合单分子层吸附的Langmuir等温吸附模型;吸附动力学研究表明,吸附以化学吸附为控制步骤,符合准二级动力学模型.

在不同改性剂作用下,采用共沉淀法制备了不同板层阳离子的CO32-型类水滑石(LDHs),并经焙烧制备了层状双金属氧化物(LDO).经筛选确定丙三醇改性Mg-Al-LDO为较适宜的Cl-脱除剂.以模拟废水中Cl-脱除量为评价指标,以丙三醇改性Mg-Al-LDO为脱氯剂,考察并确定了较适宜的Cl-脱除工艺条件,此条件下Cl-平均脱除量为40.218 mg/g,Cl-平均脱除率为75.41％.丙三醇改性Mg-Al-LDO 4次循环后的再生率为41.48％.丙三醇改性Mg-Al-LDO脱除Cl-过程符合准二级动力学方程、Langmuir等温模型.结合XRD、FT-IR表征结果推测,LDO可脱除Cl-是由于其具有"记忆效应".