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.

化工热力学是高等院校化工专业的专业基础课,在课程教学中如何融入思政元素,达到"润物无声"的效果,对于培养德才兼备、专业合格的人才具有重要意义.文章以化工热力学课程中的"气体状态方程"教学为研究对象,通过引入课程思政元素,将人生理想、科学态度、创新能力培养融入教学之中,以期达到"知识传授"与"能力培养和价值引领"相结合的育人目标.

"课程思政"成效评价体系的构建可以判断、反馈、评估"课程思政"实施情况,全面保障"课程思政"的实施.文章介绍了专业课程实施"课程思政"的意义及必要性、我校《化工热力学》"课程思政"实施现状;讨论了《化工热力学》"课程思政"成效评价体系构建的意义及必要性;着重探索了《化工热力学》"课程思政"成效评价体系的构建,包括多元化的评价主体、多维度的评价内容和多样化的评价方法."课程思政"成效评价体系的构建有利于《化工热力学》通过以评促教、以评促学和以评促改的方式持续改进"课程思政"教学质量,为新时代理工科专业课程开展相关教学研究提供重要的借鉴意义.

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.

以白云石为原料可制备碳酸钙、氢氧化镁、轻质氧化镁以及金属镁等系列产品,这些产品可广泛用于化工、建材、陶瓷、耐火材料和农业等领域.我国白云石储量大、质量优,但由于钙、镁分离困难,导致产品的纯度难以保证,因此白云石中钙、镁的高效分离是白云石综合利用的关键.通过单因素条件试验和正交试验,确定了白云石煅烧粉的相转移反应以及相转移液碳化反应的操作条件,克服了传统白云石综合利用中需强酸浸取、气液固三相反应难以控制等难题,实现了钙、镁的高效分离.该工艺反应条件温和易控、工艺流程短、原料利用率高,具有较好的工业化应用前景.

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％.

分析了研究生创新能力的培养及其对精准扶贫的重要性,论述了研究生理论创新、技术创新和集成创新能力的培养方法,介绍了合肥工业大学化学与化工学院新型肥料研究所研究生创新基地建设情况与培养效果.

讨论了"化工热力学"课程思政建设思路与目标,以课程知识点为主线,挖掘课内思政案例、课外思政内容及其思政元素,构建了课堂理论教学、课外实践教学、校内第二课堂、校外实习实践于一体,多方位、全过程开展知识传授、能力培养和价值引领的课程思政教学教育体系.教学实践结果表明,该体系有助于学生形成积极的情感态度、正确的价值观、良好的竞争意识、较强的社会责任感和宽阔的国际视野.

课程思政是新形势下课程教学改革的主要目标,也是新工科背景下教育领域人才培养的关键环节.结合课程思政内涵,总结了专业课程实施课程思政的优势、现状及存在的问题,并以合肥工业大学"化工热力学"课程为例,探索思想政治视域下的线上线下耦合教学模式:包括教学资源的建设和教学模式的实施设计.这种新的教学模式更加突出育人价值,让"立德树人"做到"润物细无声",为其他理工科专业课程开展课程思政教学研究提供有益借鉴.

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.

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％.

实习是化工专业教学过程中的一项重要实践环节,也是培养学生实践能力和创新能力的重要手段.分析了化工专业在实习中所存在的问题及原因.合肥工业大学利用校企共建实训基地,结合问题导向教学方法,探索出一种符合学生认知特点的实习课程教学与考核方式.

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.