Study on Sustained-Release Pesticides Blended with Fosthiazate-Stearic Acid/Expanded Perlite

The low utilization rate of pesticides makes the migration of pesticides in water and soil,which brings great harm to the ecosystem.The development of pesticide carriers with good drug loading capacity and release control abil-ity is an effective method to realize effective utilization of pesticides and reduce pesticide losses.In this work,fosthiazate-stearic acid/expanded perlite sustained-release particles were successfully prepared by vacuum impregnation using expanded perlite(EP)as carrier,fosthiazate(FOS)as model pesticide and stearic acid(SA)as hydrophobic matrix.The structure and morphology of the samples were studied by BET,FT-IR,TGA,XRD,DSC and SEM.The effects of different mass ratios of FOS to SA on loading capacity and release rate at 24 h were investigated.The sustained release behavior of FOS-SA/EP at different temperatures and pH values was investigated by static dialysis bag method.The results showed that FOS and SA were adsorbed in EP pores by physical interaction.With the mass ratios of FOS to SA decreasing from 7:3 to 3:7,the 24 h release rate of FOS-SA/EP decreased from 18.77%to 8.05%,and the drug loading decreased from 461.32 to 130.99 mg/g.FOS-SA/EP showed obvious temperature response at 25℃,30℃ and 35℃,the cumulative release rate(CRR)of 200 h were 33.38%,41.50%and 51.17%,respectively.When pH=5,the CRR of FOS was higher than that of pH=7,and the CRR of FOS for 200 h were 49.01%and 30.12%,respectively.At different temperatures and pH=5,the release mechanism of FOS-SA/EP belongs to the Fickian diffusion mechanism;When pH=7,the diffusion mechanism is dominant,and the dissolution mechanism is complementary.

Preparation and hygrothermal performance of composite phase change material wallboard with humidity control based on expanded perlite/diatomite/paraffin

Phase change material(PCM)can reduce the indoor temperature fluctuation and humidity control material can adjust relative humidity used in buildings.In this study,a kind of composite phase change material particles(CPCMPs)were prepared by vacuum impregnation method with expanded perlite(EP)as supporting material and paraffin as phase change material.Thus,a PCM plate was fabricated by mould pressing method with CPCMPs and then composite phase change humidity control wallboard(CPCHCW)was prepared by spraying the diatom mud on the surface of PCM plate.The composition,thermophysical properties and microstructure were characterized using X-ray diffraction instrument(XRD),differential scanning calorimeter(DSC)and scanning electron microscope(SEM).Additionally,the hygrothermal performance of CPCHCW was characterized by temperature and humidity collaborative test.The results can be summarized as follows:(1)CPCMPs have suitable phase change parameters with melting/freezing point of 18.23°C/29.42°C and higher latent heat of 54.66 J/g/55.63 J/g;(2)the diatom mud can control the humidity of confined space with a certain volume;(3)the combination of diatom mud and PCM plate in CPCHCW can effectively adjust the indoor temperature and humidity.The above conclusions indicate the potential of CPCHCW in the application of building energy efficiency.

Fabrication, property characterization and thermal performance of composite phase change material plates based on tetradecanol-myristic acid binary eutectic mixture/expanded perlite and expanded vermiculite for building application

A binary eutectic mixture composed of tetradecanol(TD)and myristic acid(MA)was maximally absorbed into the microstructures of expanded perlite(EP)and expanded vermiculite(EVMT),respectively,through a self-made vacuum adsorption roller to prepare phase change material(PCM)particle(PCP).Then EP and EVMT-based composite PCM plates were respectively fabricated through a mold pressing method.The thermal property,chemical stability,microstructure and durability were characterized by differential scanning calorimeter(DSC),Fourier transform infrared spectroscope(FT-IR),scanning electron microscope(SEM)and thermal cycling tests,respectively.The results show that both PCPs have high latent heats with 110 J/g for EP-based PCP and more than 130 J/g for EVMT-based PCP,compact microstructure without PCM leakage,stable chemical property and good durability.The research results have proved the feasibility for the vacuum adsorption roller used in the composite PCM fabrication.Results of thermal storage performance experiment indicate that the fabricated PCM plates have better thermal inertia than common building materials,and the thermal storage performance of PCM plates has nonlinearly changed with outside air velocity and temperature increase.Therefore,PCM plates show a significant potential for the practical application of building thermal storage.

Hydration Heat Effect of Cement Pastes Modified with Hydroxypropyl Methyl Cellulose Ether and Expanded Perlite

Hydration heat effect of cement pastes and mechanism of hydroxypropyl methyl cellulose ether （HPMC） and expanded perlite in cement pastes were studied by means of hydration exothermic rate, hydration heat amount, FTIR and TG-DTG. The results show that HPMC can significantly delay the hydration induction period and acceleration period of cement pastes. As mixing amount increased, hydration induction period of cement pastes enlarged and accelerated period gradually went back. At the same time, the amount of hydration heat gradually decreased. Expanded perlite had worse delay effects and less change of hydration heat amount of cement pastes than HPMC. HPMC changed the structure of C-S-H during cement hydration. The more amount of HPMC, the more obvious effect. However, EXP had little influence on the structure of C-S-H. At the same age, the content of Ca （OH）2 in cement pastes gradually decreased as the mixing amount increase of HPMC and expanded perlite, and had better delay effect than that single-doped with HPMC or expanded perlite when HPMC and expanded nerlite were both dooed in cement pastes.

Sorption Kinetics and Capacity of Composite Materials Made up of Polymeric Fabric and Expanded Perlite for Oil in Water

The oil sorption capacity of composite materials made up of different polymeric fabrics (namely acrylic fabric (AF), polypropylene nonwoven (PP), and silk stocking (SS) as composite out-packing materials) and expanded perlite (EP) was evaluated for oil removal from the water. The effects of sorbent dosage, desorption time, oil amount in the water, and contact time on composite materials sorption were investigated. The results showed that the optimum quantity of EP was between 0.5 g and 1.0 g for 25 cm2 polymeric fabrics bags. Oil removal efficiency for 6 L/m2 of oil amount in the water was 52%-72%, 44%-63%, and 37%-48% for AF, PP, and SS composite materials, respectively. Oil/water selectivity analysis of different composite materials showed that AF composite material had a very high degree of hydrophobicity and oil sorption capacity of approximately 10.17 g/g. Both oil sorption kinetics and equilibrium studies were carried out, and the equilibrium process of composite materials was described well by the Langmuir isotherm, and the oil sorption kinetics of composite materials showed good correlation coefficients for the pseudo-second order kinetic model. Intra-particle diffusion studies showed that oil sorption mechanism was controlled by the three processes, involving in external liquid membrane diffusion, surface sorption, and intra-particle diffusion.

Alkali-Silica Reactivity and Strength of Mortars with Expanded Slate, Expanded Glass or Perlite

Lightweight aggregates are increasingly used in concrete construction. They reduce concrete selfweight furnishing a structural advantage. In contrast, the mechanical properties and durability of lightweight concrete can become the governing factor on lightweight aggregate replacement ratios. Alkali-Silica Reactison (ASR) and compressive strength of mortar samples with expanded slate, expanded glass or perlite, covering the spectrum of internal porosity and weight of lightweight aggregates, were evaluated. Scanning electron microscopy was utilized to evaluate the contribution of the aggregates’ porosity and chemical composition in inhibiting ASR. Perlite, owing to its highly porous microstructure and lower matter excelled in ASR expansion while chemical composition and denser microstructure of the heavier expanded slate resulted in more signified late ASR expansion and higher compressive strength. An attempt in visual inspection of ASR attack of alkali metal ions on silica-rich expanded glass using an ultra-accelerated exposure to sodium hydroxide solution was made.

改性TiO_(2)/膨胀珍珠岩光催化剂对赤潮微藻的抑制

米氏凯伦藻是引发赤潮的经典赤潮微藻,会造成水体环境污染甚至是水中动植物死亡。将膨胀珍珠岩(EP)作为漂浮性载体,采用水热合成法、简易包衣法和海藻酸钠固定法3种方法合成的漂浮性光催化剂,并探究3种方法合成的漂浮性光催化剂对于米氏凯伦藻的抑藻作用。结果表明,水热合成法制备的漂浮式光催化剂对于米氏凯伦藻的抑藻作用最为有效,实验进行4 h后藻类去除率达到80%以上;漂浮式光催化剂作用1 h后米氏凯伦藻体内叶绿素a含量和可溶性蛋白质含量急剧下降,表明米氏凯伦藻的光合系统受到破坏,藻细胞失去了能量来源,而蛋白质含量的降低也使得藻细胞的代谢活力下降。该研究为光催化技术应用于赤潮治理提供了一定的理论依据。

模拟高原环境下敏化方式对乳化炸药爆轰性能的影响研究

为研究高原环境对不同敏化方式乳化炸药的影响程度,选取3种典型的敏化材料制备乳化炸药样品,模拟并对比分析了高原环境(-20℃、约0.05 MPa)储存后乳化炸药的微观结构和爆轰性能变化。结果表明:低温低压下的高原环境主要从加剧破坏乳化体系稳定性与热点分布两方面影响炸药的性能,在该环境下化学敏化炸药相较于物理敏化炸药的析晶程度较低,但热点变化较大,导致爆轰性能下降;物理敏化中,膨胀珍珠岩炸药晶体的生长方式更加复杂,因此更易破乳析晶,储存稳定性与爆轰性能均有明显降低;相对而言,树脂微球炸药在低温低压下的析晶程度与爆轰性能均较稳定。综合上述结果,树脂微球乳化炸药具有更好的高原适应性。

建筑用膨胀珍珠岩的资源特性及研究现状分析

对国内外建筑用膨胀珍珠岩的相关产品标准进行梳理,对膨胀珍珠岩的化学成分、微观结构及亲水机理进行分析,指出保持膨胀珍珠岩优异绝热性能的关键是改变其表层的亲水官能团及微孔结构,总结有机硅憎水剂喷涂、聚合物包覆、SiO2气凝胶填充等膨胀珍珠岩改性方法的机理及研究现状,为相关技术人员生产或使用膨胀珍珠岩提供参考。

MA/HA二元相变保温材料制备及节能效果模拟研究

为促进建筑节能,以肉豆蔻酸(MA)和碳十六酸(HA)制备二元相变材料,以膨胀珍珠岩作为吸附载体,制备一种保温材料,研究其性能。并结合建筑信息模型(BIM)节能模拟,研究该保温材料节能效果。结果表明,当MA和HA质量配比为70∶30,且保温材料中MA-HA二元相变材料质量分数为70%时,保温材料综合性能最佳。此时,MA-HA二元相变材料导热系数为0.254 W/(m·K),熔化温度和熔化潜热分别是35.64℃、123.48 J/g,凝固温度和凝固潜热分别是30.98℃、112.54 J/g。在经过1000次吸放热相变循环后,相变温度变化率不超过5%,相变潜热变化率不超过8%。BIM节能模拟表明,在使用保温材料后,建筑外围护结构能耗降幅超过30%。

膨胀珍珠岩保温板在建筑节能中的应用

文章对膨胀珍珠岩保温板的概念进行阐述,对其建筑行业应用特点进行分析,并提出其在建筑节能中的应用,为建筑行业的节能保温材料的发展提供依据。

POE水泥砂浆敷面钢丝网桁架-EPS复合板受弯性能研究

为适应装配式轻质墙板发展需要,设计了一种膨胀珍珠岩(POE)水泥砂浆敷面钢丝网桁架-聚苯乙烯泡沫(EPS)复合板(以下简称“复合板”),制作了3个足尺试件。通过静力加载试验对复合板破坏特征、抗弯承载力及变形能力进行研究,通过非线性有限元软件ABAQUS对模型进行参数分析,试验研究及有限元分析结果表明:复合板整体性较好,具有轻质高强特点,破坏时延性变形明显;复合板抗弯承载力随POE水泥砂浆层厚度、钢丝网桁架钢丝直径增大而提高,但提高程度前者有限,后者则较为明显;复合板破坏以上部水泥砂浆层压碎为标志,建议在设计时可以适当增加上部水泥砂浆层厚度。

LA-SA复合相变材料的制备与性能研究

以月桂酸-硬脂酸二元低共熔脂肪酸(LA-SA)为相变材料、膨胀珍珠岩(EP)和膨胀石墨(EG)为负载材料,采用真空吸附法制备LA-SA/EG和LA-SA/EP复合相变材料。通过FT-IR、ESEM、DSC和小室试验等对复合相变材料的化学组成、微观结构、热物性和调温性能等进行分析。结果表明,LA-SA与负载材料复合基本不改变相变材料的储放能性能;由于EG空间网络孔隙体积大,微孔和表面吸附力比EP大,故其比EP负载LA-SA能力强,EG和EP的最佳LA-SA负载率分别为90%和40%。小室试验结果表明,复合相变材料LA-SA/EG、LA-SA/EP不仅可以降低小室内最高气温,还能延迟小室内达到最高气温的时间,有效调节室内热环境;由于LA-SA/EG材料导热系数和相变潜热高,故其调温效果比LA-SA/EP更好,对建筑的节能减碳作用更显著。

建筑用复合相变材料的石膏制备和性能研究

针对传统相变材料中稳定性差、导热性差等问题,提出一种石膏基复合相变材料,通过膨胀珍珠岩和石蜡对材料进行改性,并对其性能进行研究。试验结果表明,当膨胀珍珠岩真空吸附石蜡1 h时,m(PA):m(EP)=5.106,吸附率是自然吸附时的2.5倍,其吸附过程为物理反应;制备的石膏基复合相变材料的相变潜热为70.59 J/g,相变温度为21.86℃,材料相变潜热较好,相变温度适宜;在温度由常温升至125℃过程中,材料质量损失主要是水分蒸发,相变材料石蜡未蒸发分解,材料热稳定性好;随着膨胀珍珠岩/石蜡复合相变材料掺量的增加,材料抗压强度从3.3 MPa降低至1.5 MPa,适宜掺量为7%,此时抗压强度为2.8 MPa;冻融循环试验中,当材料质量损失量最大时,质量损失率仅为1.3%。综上,试验制备的石膏基复合相变材料具有稳定性强、导热性好、耐久性良好等优点,符合建筑节能材料要求。

珍珠岩-辉绿岩石粉高性能保温砂浆制备正交试验研究

采用膨胀珍珠岩作为骨料制备保温砂浆,选取辉绿岩石粉、超细粉煤灰作为矿物掺料,通过六因素五水平正交试验,研究各组分材料掺量不同对保温砂浆参数的影响情况,并确定保温砂浆达到最佳性能时的配合比,结果表明:珍珠岩保温砂浆导热系数会随养护时间的增长,波动上涨;最优配合比结果为水泥∶骨料∶水∶可分散乳胶粉∶粉煤灰∶辉绿岩石粉=1∶1.67∶2∶0.045∶0.15∶0.225,最优组砂浆试块导热系数均值为0.0637 W/(m·K),抗压强度均值为0.927 MPa,均能满足规范要求;在单位试验组中,辉绿岩石粉掺量在在区间[0,15 g]以内,可以提高砂浆稠度并降低导热系数,在区间[0,30 g]内时,可以提高砂浆抗压强度;配制珍珠岩保温砂浆,应尽可能的增加膨胀珍珠岩掺量。

膨胀珍珠岩负载纳米零价铁高效除磷的研究

采用液相化学还原法制备纳米零价铁,并负载于膨胀珍珠岩上制备nFe@EP材料,用于去除水体中的磷酸盐。考察了溶液初始pH、温度、nFe@EP投加质量浓度和初始磷酸盐质量浓度的影响。结果表明,nFe@EP对水中磷酸盐有良好的吸附性,在温度298 K、pH 5.0、初始磷酸盐质量浓度为100 mg/L、nFe@EP质量浓度为3.0 g/L时,磷酸盐的去除率可达95.7%,吸附量达到31.9 mg/g。吸附动力学研究结果表明,伪二级吸附动力学模型能够更好地拟合nFe@EP吸附磷酸盐的行为,说明吸附过程是以化学吸附为主。热力学分析结果表明,吸附是自发放热的过程。

膨胀珍珠岩/磷钼酸铵复合材料对铯的吸附性能

磷钼酸铵(ammonium molybdophosphate,AMP)是一种对137Cs有很强选择性和离子交换能力的杂多酸盐,但其颗粒粒径较小仅约0.5~6μm,水力学性能差,后期难以进行分离操作。针对以上问题,本工作将AMP负载于膨胀珍珠岩,制备得到膨胀珍珠岩/AMP复合无机离子交换材料,对其进行X射线衍射(XRD)、扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)和电子探针显微分析仪(EPMA)等表征分析,并研究了其对Cs^(+)的吸附性能。结果表明,膨胀珍珠岩/AMP复合材料中的AMP是物理附着,稳定性较好;复合材料对Cs^(+)的吸附在120 min达到吸附平衡,其最大饱和吸附容量为13.21 mg/g;吸附过程符合准二级动力学方程(线性相关系数r2=0.99),其为化学吸附过程;等温吸附过程符合Langmuir模型(r2=0.99),表明复合材料上的吸附点是均匀的,Cs^(+)在其上面的吸附是单层吸附;共存离子Al^(3+)、Fe^(3+)和Ni^(2+)对于Cs^(+)的吸附影响较小,说明复合材料对Cs^(+)的吸附分离存在较高选择性。

利用废弃玻璃制备气凝胶及其改性膨胀珍珠岩在砂浆中的应用

从废弃玻璃中获得廉价硅源用于制备二氧化硅气凝胶(SA),并将所制得的SA负载于多孔的膨胀珍珠岩颗粒中进行有效利用.结果表明:玻璃粉在热碱液中的溶解时间须大于4 h,所形成的硅源溶液才能制成结构较为理想的SA,其孔结构和导热性能优于水玻璃;在相对真空压力-0.08 MPa下处理10 min能够制得性能优异的负载SA的膨胀珍珠岩(EPA);将制得的EPA等体积取代膨胀珍珠岩配制砂浆,随着取代率的提高,砂浆的导热系数随之减小.

膨胀珍珠岩掺量对EPS泡沫混凝土性能的影响

为了解决建筑制冷、保暖所产生的建筑能源损耗问题,本文设计了一种新型、绿色、轻质、高强自保温泡沫混凝土砌块,即将聚苯乙烯(EPS)颗粒和膨胀珍珠岩颗粒这2种隔热轻质骨料与泡沫混凝土混合制成一种新型复合泡沫混凝土,并通过测试该复合混凝土的干密度、抗压强度、孔隙率、吸水率、导热系数、含水率和燃烧质量损失率,探讨膨胀珍珠岩掺量对复合泡沫混凝土性能的影响﹒研究结果表明:一定掺量膨胀珍珠岩能增加EPS泡沫混凝土的抗压强度,降低导热系数和燃烧质量损失率,且当膨胀珍珠岩掺量为12%时,其抗压强度最高为1.66 MPa;当膨胀珍珠岩掺量为21%时,其导热系数最低为0.133 W/(m·K);当膨胀珍珠岩掺量为18%时,其燃烧质量损失率最低为4.2%;当膨胀珍珠岩掺量为6%时,该配比满足A6等级,其干密度、导热系数和抗压强度等级达到C1,吸水率等级达到W10,燃烧性能等级达到A级不燃。

相变储能保温砂浆的制备与性能研究

选择膨胀珍珠岩复合相变材料作为骨料制备相变储能保温砂浆,研究粉煤灰、可再分散乳胶粉及纤维素醚掺量对砂浆性能的影响,利用三因素三水平正交试验设计,得到粉煤灰、可再分散乳胶粉及纤维素醚掺量的最佳掺量为20%、2.2%、0.7%,利用KH550硅烷偶联剂对气凝胶进行改性,等体积取代膨胀珍珠岩复合相变材料,当气凝胶取代量为25%时,相变储能保温砂浆性能满足GB/T20473《建筑保温砂浆》所提出的Ⅰ型保温砂浆标准以及JC/T 2338《建筑储能调温砂浆》标准中的相关规定。