具有自萃取功能的相变CO_(2)吸收剂体系开发

二氧化碳(CO_(2))捕集工程应用的吸收剂存在再生能耗高、传质速率低、运行损耗大等问题,严重制约了CO_(2)捕集技术的大规模推广应用。为解决这些问题,该文开发适用于低分压CO_(2)捕集的相变吸收剂。该相变吸收体系以亲水性胺N-氨乙基哌嗪(N-aminoethyl piperazine,AEP)为主吸收体系,添加亲脂性分相剂二正丁胺(Di-n-butylamine,DPA)和活化剂(activator,ACT)。通过核磁共振波谱(nuclear magnetic resonance,NMR)和捕集CO_(2)连续测试实验研究该相变吸收剂的性能。实验结果表明,吸收负载达1.082 mol CO_(2)/mol溶液,再生温度降至98.5℃,具有优异的吸收性能和解吸性能。NMR分析表明,反应产物具有氨基甲酸盐分子结构,捕集CO_(2)连续测试实验研究与同浓度3 mol/L一乙醇胺(Monoethanolamine,MEA)溶液进行对比分析可知,相同再生能耗下,单位体积同浓度相变体系相比MEA吸收容量提高33%以上;相同再生能耗下相变体系的再生率比MEA提高15%,相同再生率下相变体系的再生能耗比MEA降低31%以上。结果表明,该相变吸收剂对于低分压CO_(2)捕集具有良好的应用前景。

Nano-SiO_(2)和镍渣掺量对碱矿渣砂浆强度和自收缩的影响

为改善碱矿渣砂浆自收缩大的缺陷,将Nano-SiO_(2)和镍渣掺入其中,研究两者掺量对抗折强度、抗压强度和自收缩的影响。研究结果表明:在镍渣掺量一定时,随着Nano-SiO_(2)掺量的增加强度值先提高后降低,掺量为1%时强度值最高,对强度的提高幅度也最大;当Nano-SiO_(2)掺量一定时,随着镍渣掺量的增加强度值逐渐降低,掺量为30%时强度降低幅度最小;当镍渣掺量为30%,随着Nano-SiO_(2)掺量的增加,自收缩值先降低后提高,掺量为1%时,自收缩值最小,对自收缩的降低幅度也最大;当Nano-SiO_(2)掺量为1%时,随着镍渣掺量的增加自收缩值逐渐降低,掺量为30%时降低幅度最大。

Hydrophilic bi-functional B-doped g-C_(3)N_(4) hierarchical architecture for excellent photocatalytic H_(2)O_(2) production and photoelectrochemical water splitting

Graphitic carbon nitride(g-C_(3)N_(4))has attracted great interest in photocatalysis and photoelectrocatalysis.However,their poor hydrophilicity poses a great challenge for their applications in aqueous environment.Here,we demonstrate synthesis of a hydrophilic bi-functional hierarchical architecture by the assembly of B-doped g-C_(3)N_(4)nanoplatelets.Such hierarchical B-doped g-C_(3)N_(4)material enables full utilization of their highly enhanced visible light absorption and photogenerated carrier separation in aqueous medium,leading to an excellent photocatalytic H_(2)O_(2)production rate of 4240.3μM g^(-1)h^(-1),2.84,2.64 and 2.13 times higher than that of the bulk g-C_(3)N_(4),g-C_(3)N_(4)nanoplatelets and bulk B doped g-C_(3)N_(4),respectively.Photoanodes based on these hierarchical architectures can generate an unprecedented photocurrent density of 1.72 m A cm^(-2)at 1.23 V under AM 1.5 G illumination for photoelectrochemical water splitting.This work makes a fundamental improvement towards large-scale exploitation of highly active,hydrophilic and stable metal-free g-C_(3)N_(4)photocatalysts for various practical applications.

醋酸纤维素水性高分子/SiO_(2)纳米复合皮革涂饰剂的制备

以A50为亲水剂,通过转换反应位点和反应官能团,调节分子链软硬段比例,引入纳米SiO_(2)提升乳液涂膜综合性能,制备WSCDA/SiO_(2)纳米复合乳液。结果表明,亲水剂A50用量为10.8%(质量分数),复合乳液及涂膜性能最优。最优条件下合成的复合乳液的平均粒径为109.5nm,粒径分布均匀,涂膜表面致密光滑,柔韧性、附着力、耐水性、耐黄变性、机械性能和热稳定性良好。WSCDA/SiO_(2)纳米复合乳液成膜时,在涂膜表面形成许多小“乳突”,产生荷叶效应,提高涂膜耐水、耐介质及耐黄变等性能。

The Effect of SiO_2 Additive on Super-hydrophilic Property of TiO_2-SiO_2 Thin Film by Sol-gel Method

TiO2-SiO2 thin films have been prepared on slide glass substrates by sol-gel method, and the effect of SiO2 additive on photo-generated hydrophilicity of TiO2 thin film was investigated by measuring the contact angle of water, the microstructure, the transmittance, the photocatalytic activity and the specific surface area . The results showed that 10mol% of SiO2 additive was the most effective for decreasing contact angle of water. The SiO2 additive of less than 30mol% has a suppressive effect on the crystal growth of anatase in calcinations, resulting in a large surface area. Consequently, the super-hydrophilicity was improved.

Reconcile the contradictory wettability requirements for the reduction and oxidation half-reactions in overall CO_(2) photoreduction via alternately hydrophobic surfaces

The overall photocatalytic CO_(2) reduction reaction(OPCRR)that can directly convert CO_(2) and H_(2)O into fuels represents a promising renewable energy conversion technology.As a typical redox reaction,the OPCRR involves two half-reactions:the CO_(2) reduction half-reaction(CRHR)and the water oxidation half-reaction(WOHR).Generally,both half-reactions can be promoted by adjusting the wettability of catalysts.However,there is a contradiction in wettability requirements for the two half-reactions.Specifically,CRHR prefers a hydrophobic surface that can accumulate more CO_(2) molecules on the active sites,ensuring the appropriate ratio of gas-phase(CO_(2))to liquid-phase(H_(2)O)reactants.Conversely,the WOHR prefers a hydrophilic surface that can promote the departure of the gaseous product(O_(2))from the catalyst surface,preventing isolation between active sites and the reactant(H_(2)O).Here,we successfully reconciled the contradictory wettability requirements for the CRHR and WOHR by creating an alternately hydrophobic catalyst.This was achieved through a selectively hydrophobic modification method and a charge-transfer-control strategy.Consequently,the collaboratively promoted CRHR and WOHR led to a significantly enhanced OPCRR with a solar-to-fuel conversion efficiency of 0.186%.Notably,in ethanol production,the catalyst exhibited a 10.64-fold increase in generation rate(271.44μmol g^(-1)h~(-1))and a 4-fold increase in selectivity(55.77%)compared to the benchmark catalyst.This innovative approach holds great potential for application in universal overall reactions involving gas participation.

Multifunctional AlPO_(4)reconstructed LiMn_(2)O_(4)surface for electrochemical lithium extraction from brine

LiMn_(2)O_(4)(LMO)electrochemical lithium-ion pump has gained widespread attention due to its green,high efficiency,and low energy consumption in selectively extracting lithium from brine.However,collapse of crystal structure and loss of lithium extraction capacity caused by Mn dissolution loss limits its industrialized application.Hence,a multifunctional coating was developed by depositing amorphous AlPO_(4)on the surface of LMO using sol-gel method.The characterization and electrochemical performance test provided insights into the mechanism of Li^(+)embedment and de-embedment and revealed that multifunctional AlPO_(4)can reconstruct the physical and chemical state of LMO surface to improve the interface hydrophilicity,promote the transport of Li^(+),strengthen cycle stability.Remarkably,after 20 cycles,the capacity retention rate of 0.5AP-LMO reached 93.6%with only 0.147%Mn dissolution loss.The average Li^(+)release capacity of 0.5AP-LMO//Ag system in simulated brine is 28.77 mg/(g h),which is 90.4%higher than LMO.Encouragingly,even in the more complex Zabuye real brine,0.5AP-LMO//Ag can still maintain excellent lithium extraction performance.These results indicate that the 0.5AP-LMO//Ag lithium-ion pump shows promising potential as a Li^(+)selective extraction system.

Evaluation of CC2 as a Decontaminant in Various Hydrophilicand Lipophilic Formulations Against Sulphur Mustard

Objective To evaluate CC2 (N, N’-dichloro-bis [2, 4, 6-trichlorophenyl] urea) invarious hydrophilic and lipophilic formulations as a personnel decontaminant for sulphurmustard (SM). Methods Twenty percent of CC2 was prepared as a suspension or ointmentwith various chemical agents and its stability was evaluated by active chlorine assay. Theefficacy was evaluated in mice by recording the mortality after applying 29 LD50 of SM (LD50 =8.1 mg/kg dermally) and decontaminating it after 2 min with 200 mg of the formulation.Studies were also carried out with 10% and 20% CC2 in acacia and hydroxypropyl cellulose,and the suspensions were stored in polyethylene containers. The stability of the suspensionswas evaluated by active chlorine assay. The efficacy was evaluated by recording themortality after applying 29 LD50 of SM in mice and 12 LD50 of SM in rats (LD50 = 2.4 mg/kgdermally), and decontaminating it with the formulations. LD50 by different routes andprimary skin irritation test of CC2 were also carried out. Results CC2 reacted with peanutoil and neem oil, and was unstable in povidone iodine and Fuller’s earth. Good stability wasachieved with petroleum jelly, honey, polyvinyl pyrrolidone, calamine lotion, acacia andhydroxypropyl cellulose. Though CC2 was stable in lipophilic formulations, it did notprotect the animals. The hydrophilic formulations particularly acacia and hydroxypropylcellulose gave very good protection and was stable in the polyethylene containers for aperiod of 1 year. The efficacy of 20% CC2 was better than 10% CC2. The oral and dermalLD50 of CC2 was found to be above 5.0 g/kg. CC2 was also found to be nonirritant.Conclusion Twenty percent of CC2 in hydroxypropyl cellulose is better with respect tostability, efficacy and ease of decontamination. CC2 is also a safe chemical.

Plasma-Assisted Chemical Vapor Deposition of TiO₂Thin Films for Highly Hydrophilic Performance

Titanium-oxide layer was grown on glass substrate by plasma-assisted chemical vapor deposition (PCVD) using oxygen gas plasma excited by radio-frequency power at 13.56 MHz in the pressure as low as 3mtorr at relatively low temperature below 400oC, and studied on the crystallographic properties with the hydrophilic behavior comparing to the layer deposited by low-pressure chemical vapor deposition (LPCVD). Raman spectra indicated anatase-phase TiO2 layer without amorphous-phase could be formed above 340oC by simultaneous supply of plasma-cracked and non-cracked titanium-tetra-iso-propoxide (TTIP) used as preliminary precursor. Surface Scanning Electron Microscope images indicated the PCVD-layer consists of distinct nanometer-size plate-like columnar grains, in contrast to rugged micrometer-size grains in the LPCVD-layer. Extremely small water contact angle about 5o in dark and the quick conversion to super-hydrophilicity by UV-irradiation with a light-power density as low as 50 W/cm2 were observed on the PCVD- layer grown at 380oC, while the large initial contact angle was above 40o and the response for the UV-irradiation was gradual on the LPCVD-layer.

Effect of hydrophilic silica nanoparticles on hydrate formation: Insight from the experimental study

Invasion of drilling fluid into natural gas hydrate deposits during drilling might damage the reservoir,induce hydrate dissociation and then cause wellbore instability and distortion of the data from well logging. Adding nanoparticles into drilling fluid is an effective method in reducing the invasion of drilling fluid and enhancing borehole stability. However, the addition of nanoparticles might also introduce hydrate formation risk in borehole because they can act as the "seeds" for hydrate nucleation. This paper presents an experimental study of the effect of hydrophilic silica nanoparticle on gas hydrate formation in a dynamic methane/liquid-water system. In the experiment, the ultrapure water with and without1.0 wt%–6.0 wt% concentrations of silica nanoparticles, grain sizes of 20 and 50 nm, were pressurized by methane gas under varied conditions of temperature and pressure. The induction time, the gas consumption, and the average rate of gas consumption in the system were measured and compared to those in ultrapure water. The results show that a concentration of 4.0 wt% hydrophilic SiO_2 particles with a grain size of 50 nm has a relatively strong inhibition effect on hydrate formation when the initial experimental condition is 5.0 °C and 5.0 MPa. Compared to ultrapure water, the hydrophilic nano-SiO_2 fluid increases the induction time for hydrate formation by 194% and decreases the amount and average rate of hydrate formation by 10% and 17%, respectively. This inhibition effect may be attributed to the hydrophilicity,amount and aggregation of silica nanoparticle according to the results of water activity and zeta potential measurements. Our work also elucidates hydrophilic, instead of hydrophobic, nanoparticles can be added to the drilling fluid to maintain wellbore stability and to protect the hydrate reservoir from drilling mud damage, because they exhibit certain degree of hydrate inhibition which can reduce the risk of hydrate reformation and aggregation during gas hydrate or deep water drilling if their concentration can be controlled properly.

Research on a New Process of Preparation for Nano-SiO_2 with High Activity and Mesopores

Nano-SiO_2 with high activity and mesopores was prepared through sol-gel synthesis followed by low-temperatureheat treatment and ball milling firstly in our experiments. TEM was performed to measure particle sizes. Nitrogenadsorption experiments were carried out to estimate specific surface area, porous distribution and porous ratio by BETand BJH methods. The content of Si-OH in SiO_2 surface was calculated by analysis of the results of hydrogen-oxygencontent mensuration (HOCM). As a result, appropriate heat treatment system and ball milling time are important topreparation for nano-SiO_2 with high activity and mesopores, which are 5～50 nm particles, 5～6 nm average aperture,85%～93% porous ratio, and 51%～55% Si-OH content in surface. Nano-SiO_2 with that structure has high surfaceenergy and activity. This process, which has simple facilities and operation rules, is a new way of preparation fornano-SiO_2 with high activity and mesopores.

亲水相互作用色谱-静电场轨道阱高分辨质谱法测定CO_(2)吸收液中9种有机胺类化合物

二氧化碳(CO_(2))吸收捕集是实现我国碳达峰和碳中和目标的有效措施。有机胺类化合物被广泛用作工业回收CO_(2)的吸收剂,建立有机胺类化合物的分析检测方法对于碳捕集与封存(CCS)技术和碳捕获、利用与封存(CCUS)技术的发展具有重要意义。本研究建立了以亲水相互作用色谱-静电场轨道阱高分辨质谱法同时测定CO_(2)吸收液中9种有机胺类化合物的分析方法。样品以水作为溶剂,稀释后经0.22μm尼龙滤膜过滤后,进样分析。采用Accucore HILIC色谱柱(100 mm×2.1 mm,2.6μm),在30℃条件下进行分离,流动相A为90%乙腈水溶液(含5 mmol/L甲酸铵和0.1%甲酸),流动相B为10%乙腈水溶液(含5 mmol/L甲酸铵和0.1%甲酸),梯度洗脱。采用电喷雾离子源(ESI),在正离子模式下进行测定,通过标准加入法进行定量分析。实验对比了不同色谱柱对有机胺类化合物的保留能力以及不同流动相的影响,并对方法进行了方法学验证。结果表明:9种有机胺类化合物在0.04~25000 ng/mL范围内线性关系良好,线性相关系数(R 2)均≥0.9910;方法的检出限(LOD)为0.0004~0.0080 ng/mL,方法的定量限(LOQ)为0.0035~0.0400 ng/mL;在1、1.5、3倍样本浓度添加水平下,方法的平均回收率为85.30%~104.26%,相对标准偏差(RSD)为0.04%~7.95%。应用建立的方法对某项目现场样品的吸收废液进行检测,9种有机胺类化合物均能被有效检测。对实际样品进行稳定性测试,于4℃条件下,在48 h内RSD为0.10%~6.35%。该方法灵敏、准确、快速、简便,可为有机胺类化合物的检测提供参考,并为CO_(2)捕集技术的开发和工业化应用提供有力的技术支持。

Mechanical Properties and Fire Retardancy of Wood Flour/High-Density Polyethylene Composites Reinforced with Continuous Honeycomb-Like Nano-SiO_(2)Network and Fire Retardant

The mechanical properties of wood flour/high-density polyethylene composites(WPC)were improved by adding a small amount of nano-SiO_(2)to obtain a network-structured WPC with a continuous honeycomb-like nano-SiO_(2)network.The wood flour was modified with a fire retardant(a mixture of sodium octabonate and amidine urea phosphate)to improve its fire retardancy.The flexural properties,creep resistance,thermal expansion,and fire retardancy of the WPC were compared to a control(WPCCTRL)without nano-SiO_(2)or fire retardant.The flexural strength and modulus of the WPC containing only 0.55 wt.%nano-SiO_(2)were 6.6%and 9.1%higher than the control,respectively,while the creep strain and thermal expansion rate at 90°C were 33.8%and 13.6%lower,respectively.The cone calorimetry tests revealed that the nano-SiO_(2)network physically shielded the WPC,giving it lower heat release and smoke production rates.The thermal expansion was further decreased by incorporating fire retardants into the WPC,which showed the lowest total heat release and total smoke production and the highest mass retention.This study demonstrates a facile procedure for producing WPC with desired performances by forming a continuous honeycomb-like network by adding a small amount of nanoparticles.

Surface Modification of Polyglycolic Acid Fibers by Hydrogen Peroxide for Enhancing Hydrophilicity and Cytocompatibility

Hydrogen peroxide( H_2O_2) is applied for surface modification of polyglycolic acid( PGA) fibers in order to enhance the hydrophilicity and cytocompatibility of PGA fibers effectively,and maintain the breaking strength as the same time. PGA fibers are dipped in H_2O_2 solution a certain time for modification. Scanning electron microscopy( SEM) was used to observe the surface morphology of PGA fibers before and after modification. The varying of PGA macromolecule was examined with Fourier transform infrared spectroscopy( FTIR) analyses. X-ray diffraction( XRD) and differential scanning calorimetry( DSC) analysis showed that crystallinity slightly decreases. Mechanical performance test showed tensile force of modified PGA fiber was increased. The water contact angle test indicated the improving of hydrophilic. A cell proliferation assay showed that fibroblast cells attach and proliferate well on the fibers, which meant the modified fibers possess good cytocompatibility. These results suggest that H_2O_2 surface modification is easy to operate and a advantageous modification method for PGA fibers.

Effect of nano TiO_(2) and SiO_(2) on gelation performance of HPAM/PEI gels for high-temperature reservoir conformance improvement

Nanoparticles have been widely used in polymer gel systems in recent years to improve gelation performance under high-temperature reservoir conditions. However, different types of nanoparticles have different effects on their gelation performance, which has been little researched. In this study, the high-temperature gelation performance, chemical structure, and microstructure of polymer gels prepared from two nanomaterials (i.e., nano-SiO_(2) and nano-TiO_(2)) were measured. The conventional HPAM/PEI polymer gel system was employed as the control sample. Results showed that the addition of nano-TiO_(2) could significantly enhance the gel strength of HPAM/PEI gel at 80 ℃. The gel strength of the enhanced HPAM/PEI gel with 0.1 wt% nano-TiO_(2) could reach grade I. The system also had excellent high-temperature stability at 150 ℃. The enhanced HPAM/PEI gel with 0.02 wt% nano-TiO_(2) reached the maximum gel strength at 150 ℃ with a storage modulus (G′) of 15 Pa, which can meet the need for efficient plugging. However, the nano-SiO_(2) enhanced HPAM/PEI polymer gel system showed weaker gel strength than that with nano-TiO_(2) at both 80 and 150 ℃ with G′ lower than 5 Pa. Microstructures showed that the nano-TiO_(2) enhanced HPAM/PEI gel had denser three-dimensional (3D) mesh structures, which makes the nano-TiO_(2) enhanced HPAM/PEI gel more firmly bound to water. The FT-IR results also confirmed that the chemical structure of the nano-TiO_(2) enhanced HPAM/PEI gel was more thermally stable than nano-SiO_(2) since there was a large amount of –OH groups on the structure surface. Therefore, nano-TiO_(2) was more suitable as the reinforcing material for HPAM/PEI gels for high-temperature petroleum reservoir conformance improvement.

NiAl_(2)O_(4)涂层膜的制备及其在油水分离中的应用

以聚偏氟乙烯(PVDF)有机膜为基底,单宁酸(TA)为胶结剂,将尖晶石NiAl_(2)O_(4)无机纳米颗粒均匀修饰到PVDF膜表面,制备了超亲水/水下超疏油型NiAl_(2)O_(4)/TA/PVDF复合膜。系统研究了NiAl_(2)O_(4)/TA/PVDF复合膜的结构、形貌和表面润湿性,评价了复合膜在典型的油水乳液分离中的性能。实验结果表明,NiAl_(2)O_(4)/TA/PVDF复合膜对稳定的油水乳液表现出优异的分离效率(分离效率均高于99%)和较高的膜通量(682~1302 L·m^(-2)·h^(-1))。此外,由于膜表面的粗糙结构和特殊润湿性,NiAl_(2)O_(4)/TA/PVDF复合膜具有较好的抗油污染性能,在循环8次分离水包油乳液后仍具有较高的分离效率和膜通量,表现出良好的机械性能和可再生性。本研究为构筑尖晶石基油水分离膜及其在油水分离中的应用提供了新的思路。

CO_(2)激光对聚酰亚胺织物的表面改性研究

采用波长为10.6μm的CO_(2)激光对聚酰亚胺织物进行表面改性。通过单因素试验优化激光改性工艺参数,测试改性后织物滴水扩散时间、接触角和抗弯刚度,分析CO_(2)激光改性聚酰亚胺织物的作用机制,探讨激光改性对聚酰亚胺织物颜色参数、表面形貌、分子结构及结晶度的影响。结果表明:激光改性能够改善聚酰亚胺织物的亲水性,随着激光功率的增加及扫描速度、激光步距的减小,改性聚酰亚胺织物的滴水扩散时间和接触角呈下降趋势,亲水性提升;优化的激光改性工艺参数为激光功率20 W、扫描速度200 mm/s、激光步距0.2 mm,此时激光能量密度为40 J/cm 2;激光的光热作用造成聚酰亚胺大分子链断裂并在分子链中引入羟基等极性基团,以及激光产生的刻蚀造成织物表面粗糙度增加,是织物亲水性提高的主要原因;CO_(2)激光改性后聚酰亚胺织物的颜色参数基本不变,结晶度和断裂强力下降。

退火温度对纳米TiO_2薄膜结构和亲水性的影响

采用射频磁控溅射方法制备出纳米二氧化钛 (TiO2 )薄膜 ,研究了不同退火温度对薄膜微观结构和超亲水性的影响。结果表明 :退火温度升高 ,晶粒长大 ,孔隙率减小 ;常温制备 30 0℃以下退火的TiO2 薄膜为无定形结构 ,亲水性差 ;4 0 0℃～ 6 5 0℃退火的薄膜为锐钛矿结构 ,表现出超亲水性 ;80 0℃退火薄膜为金红石结构 。

紫外光下纳米TiO_2薄膜亲水性机理的电化学研究

利用溶胶 凝胶方法在透明导电玻璃ITO (SnO2 ∶In)表面制备纳米TiO2 薄膜 ,XRD谱图表明TiO2 是锐钛矿晶型 ,AFM (Atomic Force Microscope)测得薄膜表面粒子约为 10 0nm .研究了ITO表面纳米TiO2 薄膜的光致亲水性变化 .通过循环伏安技术测定TiO2 薄膜电极在 2 5 3.7nm的紫外光照射后的电化学行为推测光致亲水性机理 .发现在紫外光照射一定时间后 ,TiO2 薄膜电极的循环伏安图在 +0 .0 35V处出现新的氧化峰 ;且随光照时间的增加 ,氧化峰的峰电流增大 ,溶液中的溶解氧对峰电流的大小有明显影响 .实验表明 ,在紫外光照下电极表面有Ti3 + 产生 ,证实了TiO2 薄膜的光致亲水性转变过程与Ti3 +

射频磁控共溅射制备超亲水TiO_2/SiO_2复合薄膜

采用射频磁控共溅射法制备了SiO2 /TiO2 复合薄膜 ,通过控制SiO2 靶与TiO2 靶的溅射时间可调节SiO2 与TiO2 的比例。所制备的SiO2 /TiO2 薄膜为锐钛矿结构。实验结果表明 :SiO2 的掺入降低了SiO2 /TiO2 复合薄膜的光催化能力 ,但却提高了薄膜的亲水性的维持时间。其中 ,掺入 6 %～ 13%SiO2 的SiO2 /TiO2 复合薄膜 ,在紫外光照射 30min ,接触角降到 2° ;停止照射后 ,在 5天内接触角小于 6°。