Micromorphology and physicochemical properties of hydrophobic blasting dust in iron mines

The micromorphology and physicochemical properties of hydrophobic blasting dust(HBD)from an iron mine were comprehensively analyzed by laser particle size analysis(LPSA),scanning electron microscopy(SEM),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).The results show that the HBD particles can be classified into three types based on their particle size(PS):larger particles(PS>10μm),medium particles(1μm≤PS≤10μm),and nanoparticles(PS<1μm).The cumulative volume of respirable dust(PS≤10μm)was 84.45%.In addition,three shapes of HBD were observed by SEM:prism,flake,and bulk.In particular,the small particles were mostly flaky,with a greater possibility of being inhaled.Furthermore,the body and surface chemical compounds of HBD were determined by XRD and XPS,respectively.Ammonium adipate(C6H16N2O4)was the only organic compound in the body of HBD,but its mass fraction was only 13.4%.However,the content of organic C on the surface of HBD was 85.35%.This study demonstrated that the small-particle size and large amount of organic matter on the surface of HBD are the main reasons for its hydrophobicity,which can provide important guidance for controlling respirable dust in iron mines.

Synthesis and characterization of high strength polyimide/silicon nitride nanocomposites with enhanced thermal and hydrophobic properties

Polyimide(PI)composite films were synthesized incorporating amino modified silicon nitride(Si_(3)N_(4))nanoparticles into PI matrix via in situ polymerization technique.The mechanical and thermal performances as well as the hydrophobic properties of the as prepared composite films were investigated with respect to the dosage of the filler in the PI matrix.According to Thermogravimetric(TGA)analysis,meaningful improvements were achieved in T5(5%weight loss temperature)and T10(10%weight loss temperature)up to 54.1℃ and 52.4℃,respectively when amino functionalized nano Si_(3)N_(4) particles were introduced into the PI matrix.The differential scanning calorimetry(DSC)results revealed that the glass transition temperature(Tg)of the composites was considerably enhanced up to 49.7℃ when amino functionalized Si_(3)N_(4) nanoparticles were incorporated in the PI matrix.Compared to the neat PI,the PI/Si_(3)N_(4) nanocomposites exhibited very high improvement in the tensile strength as well as Young’s modulus up to 105.4%and 138.3%,respectively.Compared to the neat PI,the composites demonstrated highly decreased water absorption behavior which showed about 68.1%enhancement as the content of the nanoparticles was increased to 10 wt%.The SEM(Scanning electron microscope)images confirmed that the enhanced thermal,mechanical and water proof properties are essentially attributed to the improved compatibility of the filler with the matrix and hence,enhanced distribution inside the matrix because of the amino groups on the surface of Si_(3)N_(4) nanoparticles obtained from surface functionalization.

Synthesis and application of a hydrophobic hypercrosslinked polymeric resin for removing VOCs from humid gas stream

A hydrophobic hypercrosslinked polymeric resin LC-1 was prepared and characterized. The properties of LC-1 resin were compared with those of a commercial hypercrosstinked polymer NDA-201 resin. In addition, the dynamic adsorption of trichloroethylene （TCE） onto LC-1 under dry and humid conditions at 303 K was investigated, the result shows that LC-1 possesses high hydrophobic property and can remove TCE from gas stream without effect of high humidity efficiently.

Double network self-healing hydrogel based on hydrophobic association and ionic bond for formation plugging

Self-healing hydrogels have attracted tremendous attention in the field of oil and gas drilling and production engineering because of their excellent self-healing performance after physical damage.In this study,a series of double network self-healing(DN_(SA))hydrogels based on hydrophobic association and ionic bond were prepared for plugging pores and fractures in formations in oil and gas drilling and production engineering.The mechanical,rheological,and self-healing properties of the DN_(SA)hydrogels were investigated.Results revealed that the DN_(SA)hydrogels exhibited excellent mechanical properties with a tensile stress of 0.67 MPa and toughness of 7069 kJ/cm^(3) owing to the synergistic effect of the double network.In addition,the DN_(SA)hydrogels exhibited excellent compression resistance,notch insensitivity,and self-healing properties.The DN_(SA)-2 hydrogel was granulated and made into gel particles with different particle sizes and used as a plugging agent.The self-healing mechanism of DN_(SA)-2 hydrogel particles in fractures was explored,and it’s plugging effect on fractures of different widths and porous media of different permeabilities were investigated.Experimental results revealed that the plugging capacity of the DN_(SA)-2 hydrogel particles for a fracture with width of 5 mm and a porous medium with a permeability of 30μm^(2) was 3.45 and 4.21 MPa,respectively,which is significantly higher than those of commonly used plugging agents in the oilfield.The DN_(SA)hydrogels with excellent mechanical and self-healing properties prepared in this study will provide a new approach for applying hydrogels in oil and gas drilling and production engineering.

One-step synthesis of hydrophobic magnesium hydroxide nanoparticles and their application in flame-retardant polypropylene composites

Hydrophobic magnesium hydroxide(MH) nanoparticles were prepared by a one-step synthesis method in a high-gravity environment generated by a novel impinging stream–rotating packed bed(IS-RPB) reactor. The reactant solutions were simultaneously and continuously pumped into the IS-RPB reactor, and then Tween80 was added as a surface modifier. The morphology, structure, and properties of blank and hydrophobic MH were characterized. The effects of MH nanoparticles on the flame retardancy, thermal stability, and mechanical properties of PP/MH composites were also studied. We found that the obtained MH nanoparticles exhibited hexagonal lamella with a mean size of 30 nm, excellent hydrophobic properties(e.g., high water contact angle of 112°), and improved thermal stability of MH. The limiting oxygen index(LOI) further showed that increased MH loading can significantly improve flame-retardant performance, which reached 29.3% for PP/MH composites with 30 wt% hydrophobic samples. The thermal stability and mechanical properties of the PP/MH composites with hydrophobic samples were also much higher than those of PP/MH composites with blank MH. Results showed that the one-step synthesis had high potential application in the large-scale production of hydrophobic MH nanoparticles.

Hydrophobic epoxy resin coated proppants with ultra-high self-suspension ability and enhanced liquid conductivity

Proppant is a key material for enhancing unconventional oil and gas production which requires a long distance of migration and efficient liquid conductivity paths within the hydraulic fracture.However,it is difficult to find a proppant with both high self-suspension ability and liquid conductivity.Here,a simple method is developed to coat epoxy resin onto the ceramic proppant and fabricate a novel coated proppant with high hydrophobicity,self-suspension,and liquid conductivity performance.Compared with uncoated ceramic proppants,the epoxy resin coated(ERC) proppant has a high self-suspension ability nearly 16 times that of the uncoated proppants.Besides,the hydrophobic property and the liquid conductivity of the ERC proppant increased by 83.8% and 16.71%,respectively,compared with the uncoated proppants.In summary,this novel ERC proppant provides new insights into the design of functional proppants,which are expected to be applied to oil and gas production.

Preparation and Characterization of Hydrophobic Bagasse Hemicellulosebased Films

To improve the hydrophobicity of bagasse hemicellulose-based films,glutaraldehyde was applied when preparing films of original and cationic bagasse hemicellulose with the addition of polyvinyl alcohol and sorbitol.The results showed that the cationic modification could increase the hydrophobicity of the hemicellulose-based film,and the hydrophobicity of hemicellulose-based films crosslinked with glutaraldehyde also increased.However,cationic modification of hemicellulose decreased the stress of the hemicellulose-based film.While crosslinking with glutaraldehyde increased the stress of both the original and cationic hemicellulose-based films.Macrophotography indicated that the film formability of the original hemicellulose was better than that of cationic hemicellulose.Through SEM observation,the degree of bonding of different components of the films was found to be increased due to crosslinking with glutaraldehyde.The crosslinking reaction between glutaraldehyde and hemicellulose was further confirmed by FT-IR spectroscopy.

Mechanical Properties, Biocompatibility and Anti-Bacterial Adhesion Property Evaluation of Silicone-Containing Resin Composite with Different Formulae

Novel branched silicone methacrylate was developed.The mechanical and biological properties of the resin system were investigated to select the formula proportion with the best overall performance.The novel silicone-containing monomers were combined with an incremental sequence of glass filler concentrations in commonly used Bis-GMA/TEGDMA(50/50,wt./wt.)dental resin systems.Physicochemical properties,surface properties,antibacterial adhesion effect,anti-biofilm effect,protein adsorption,and cytotoxicity were evaluated.The results showed that BSMs did not affect the double bond conversion of dental resin,but could reduce volumetric shrinkage(p<0.05).The BSM containing resins can resist protein and bacteria adhesion(S.mutans)because it has increased hydrophobicity and a lower free energy surface(p<0.05).However,there were no statistically significant differences in cytotoxicity,surface roughness,and double bond conversion rate.Overall,the results indicate that changes in a material’s properties are not strictly proportional to its composition.Synthetic silicone resin methacrylate can reduce the polymerization shrinkage,have low surface energy and anti-adhesion properties.Silicone composite resin containing 70%matrix has the best comprehensive properties.The silicone methacrylate composite represents an innovative method to improve the properties and reducing secondary caries.

OLEOPHOBIC AND HYDROPHOBIC FEATURE EXPERIMENTS OF FLUORINATED HIGH DENSITY POLYETHYLENE

The surface performances of directly fluorinated high density polyethylene(HDPE)are studied with Fourier transform infrared(FT-IR)spectra,scanning electron microscopy(SEM)and contact angle(CA)system. The SEM images show that there is a three-layer structure called the reaction,virgin and boundary layer structure. The depth of fluorinated layer is 5.75μm with 1h fluorination time and 7.86μm with 2h.The depths are 5.46μm and 5.07μm when fluorine density is 2% and 1%,respectively.CA indicates that the HDPE surface property becomes more hydrophobic with the increasing water contact angle from 78.5° to 104.5°.Oleophobic and hydrophobic features of HDPE are identified by comparison of mass change experiments.It is shown that the increment rate of fluorinated HDPE is much lower than that of un-fluorinated HDPE filled in neither distilled water nor jet fuel.

基于疏水仿生学提升超细高氯酸铵热分解、安全及防吸湿性能的研究

为了研制出兼具高燃速和高安全性能的固体推进剂,以改善高氯酸铵的性能为目标,采用液相沉积法制备了具有核壳结构的超细高氯酸铵@硬脂酸锌(UF-AP@ZnSA)复合物;使用扫描电镜(SEM)、热重-差示扫描量热法(TG-DSC)、傅里叶变换红外光谱(FT-IR)等对样品的形貌、结构和热分解性能进行了表征;并测量了样品的撞击感度、摩擦感度、吸湿率和接触角等参数;采用热分析-红外联用技术分析并解释了硬脂酸锌(ZnSA)催化UF-AP的热分解机理。结果表明,UF-AP表面生成了ZnSA壳层;不同壳层含量的复合物中UF-AP高温分解峰从424.3℃降至370~385℃,相较于原料UF-AP,放热区间更加集中,放热量更大;UF-AP@ZnSA复合物特性落高(H_(50))相较于原料增加了27.6 cm,摩擦感度的爆炸概率减小了76%,安全性能大幅度提升;壳层质量分数为5%的UF-AP@ZnSA复合物72 h的吸湿率为0.05%,较原料UF-AP的吸湿率降低约90%,防吸湿性能得到明显提升。

小麦加工前中后路粉面筋蛋白特性差异性分析

以同一生产线不同出粉点的小麦粉制备的面筋蛋白为原料,在测定面筋蛋白基本理化组分性质基础上再分别测定其游离巯基含量、表面疏水性、麦谷蛋白大聚体(glutenin macropolymer,GMP)含量与流变学特性,探讨前中后路粉面筋蛋白理化性质以及流变学特性差异。实验发现,前路粉面筋蛋白的灰分、蛋白质含量、游离巯基含量、表面疏水性低于后路粉面筋蛋白(P≤0.05),而吸水率、面筋指数与GMP含量高于后路粉面筋蛋白(P≤0.05),流变学实验结果表明前路粉面筋蛋白中的储能模量、损失模量均大于后路粉面筋蛋白,后路粉面筋蛋白更容易发生形变且最大形变量显著高于前路粉面筋蛋白。

兼具优异光学性能和疏水疏油性能的含氟聚降冰片烯二甲酰亚胺的制备与性能

针对聚降冰片烯材料的传统热性能提高改性策略会导致光学性能大大下降的问题,文中以全氟己基碘烷、对溴苯胺和纳迪克酸酐等原料设计合成了一种侧基带有对全氟己基苯结构的降冰片烯二甲酰亚胺单体,并将其通过开环易位聚合制备了一种新型含氟降冰片烯基均聚物(PNANPF6),以及合成了侧基分别为苯(PNANP)、对甲基苯(PNANPC1)、对三氟甲基苯(PNANPF1)、对己基苯(PNANPC6)4种结构相似的均聚物作为对照,通过核磁共振波谱和红外光谱表征证明了聚合物的成功制备。结果表明,在热性能和力学性能可基本保持的前提下,PNANPF6的水/正十二烷接触角相比PNANP提高了18°/26°;在400 nm/800 nm处的透光率相比PNANP提高了36%/22%。充分证明酰亚胺、苯环和全氟己基结构的引入可协同提高降冰片烯聚合物的光学性能和疏水疏油性能。为新型多功能降冰片烯聚合物的制备提供一条新思路。

疏水CY184/E-PDMS环氧树脂复合材料的制备及性能

环氧树脂虽然具有良好的耐漏电流和抗击穿等电气性能和力学性能,但由于其本身缺乏疏水性,因此在户外绝缘子领域难以大范围应用。为了解决环氧树脂疏水差的问题,采用γ-氨丙基三乙氧基硅烷(APTES)、六氢邻苯二甲酸双缩水甘油酯(CY184)对羟基封端的聚二甲基硅氧烷(HPDMS)进行改性,合成了含有环氧基团的疏水改性剂E-PDMS,并制备了CY184/E-PDMS复合材料。结果表明,接枝了环氧基团的E-PDMS与CY184相容性良好,当E-PDMS质量分数达到10%时,复合材料水接触角能稳定在105°,呈现疏水性;体积电阻率提升至1.36×10^(14)Ω·m,介电常数在1000 Hz下降低至3.55,玻璃化转变温度和拉伸强度分别提升至117℃和59.4 MPa。经过E-PDMS改性后,CY184环氧树脂的疏水性、绝缘性、力学性能、热稳定性等均有明显提升,拓宽了CY184环氧树脂在绝缘子领域的应用。

涤纶/黏胶纤维复合针刺非织造布的制备及疏水整理

以聚酯纤维和黏胶纤维为原料,混合成网后通过针刺工艺制备具有多孔隙的三维结构的涤纶/黏胶纤维复合针刺非织造布;然后,选用氟化后的纳米SiO_(2)颗粒和SiC颗粒对非织造布进行表面进行疏水整理,并对试样的克重及厚度、化学结构、微观形貌、机械力学性能、疏水性能等进行研究,分析原料配比对产品各项性能的影响。结果表明:纤维表面富含大量的纳米SiO_(2)颗粒和SiC颗粒,且适当提高涤纶纤维的含量,可改善试样的机械力学性能和疏水性能。基于以上良好的性能,涤纶/黏胶纤维复合针刺非织造布可用于防水领域。

硅烷KH602改性PVDF/PU纤维膜的制备及疏水吸油性研究

采用静电纺丝技术制备聚偏氟乙烯/聚氨酯(PVDF/PU)混纺纤维膜,后通过浸渍法将硅烷KH602引入纤维膜中以提高纤维膜疏水性和力学性能。结果表明:KH602改性后的纤维膜水接触角和力学性能得到提升,能选择性吸收油水混合物中的油,且吸油后能漂浮在水面上,对机油、花生油和菜籽油的吸附倍率分别为50.67g/g、45.94g/g、43.29g/g,经过10次循环吸油后仍保持较高的吸油倍率,与准二级吸附方程比较,准一级吸附方程能更加准确地描述该纤维膜吸油过程。

甲基丙烯酸十三氟辛酯改性胺固化剂增韧环氧清漆涂层的性能和机理研究

[目的]氢化双酚A二缩水甘油醚环氧树脂(HBPA-EP)基涂层应用时脆性大、韧性不足、疏水性较差等问题亟待解决。[方法]使用甲基丙烯酸十三氟辛酯(C6F)对异佛尔酮二胺(IPDA)固化剂进行改性后,与HBPA-EP反应固化为涂层,研究了改性剂掺量对涂层疏水性能、力学性能、耐化学品性能和耐沾污性能的影响。采用傅里叶变换红外光谱仪(FT-IR)和核磁共振氢谱仪(1H-NMR)分析了C6F对IPDA的改性机理。采用扫描电子显微镜(SEM)和能量色散谱仪(EDS)对涂层拉伸断面形貌及表面氟元素的分布进行表征。[结果]C6F的氟碳链结构被成功引入到IPDA分子中。采用C6F改性IPDA制备的涂层在疏水性能和力学性能上都得到明显提高。C6F与IPDA的物质的量比为0.5∶1.0时所得涂层的性能最佳,其水接触角为118.2°,铅笔硬度达到2H,柔韧性为1 mm,粘结强度为16.2 MPa,在浸水、浸碱和浸酸8 d后未出现吸水溶胀现象,表面也具有良好的抗涂鸦沾污性能。[结论]改性后的IPDA与HBPA-EP反应形成了交联网状结构,氟碳键的存在使网状结构交联更加致密,实现了对HBPA-EP交联体系的有效调节,令改性涂层的疏水性能和力学性能均得到改善。

基于竹粉表/界面调控的竹塑复合材料的制备及性能分析

为改善竹粉与非极性聚合物之间的界面相容性,以NaOH溶液及甲基三甲氧基硅烷(MTMS)对竹粉进行协同改性,然后与线型低密度聚乙烯(LLDPE)均匀混合热压制备了竹塑复合材料(BPC)。对改性前后竹粉的化学结构、润湿性及所制备BPC的力学性能、断面形貌、吸水性和尺寸稳定性进行了分析和表征。结果表明,经NaOH溶液处理的竹粉其亲水性增强,结晶度增加,用MTMS进一步改性后其表面引入了低表面能的Si—CH_(3)基团,竹粉由亲水性转变为疏水性;NaOH与MTMS协同改性竹粉与未改性竹粉制备的BPC相比,其抗拉强度和静曲强度分别提高了29.5%、28.6%,吸水率由16%下降到8%,24 h吸水厚度膨胀率由3.4%下降到1.3%。

基于熔融共混法制备PP/PVDF疏水体系的结构和性能研究

采用熔融共混法,制备系列PP/PVDF共混体系,讨论不同原料配比和不同牌号PVDF原料对PP/PVDF共混体系对纯水的接触角、对蛋白上样缓冲液的流挂性能,以及透光性能等方面的影响。结果表明,随着PVDF含量的增加,PP/PVDF共混体系对纯水接触角呈先上升后下降趋势,当PVDF含量为10%时,共混体系对纯水的接触角达最大值为117°;当PP/PVDF共混体系中的PVDF含量相同(5%、15%、25%)时,利用牌号为710的PVDF制备的共混体系对纯水接触角最大,测试样条表面残留的蛋白上样缓冲液最少,牌号为720的次之,牌号为705的接触角最小,残留的蛋白上样缓冲液最多;而对于共混体系的透光率,则是利用牌号为705的PVDF制备的共混体系透光率最大,牌号为720的次之,牌号为710的透光率最低。

疏水改性微球的制备及其膨胀性能与应用研究

通过反相乳液聚合法制备了一种疏水改性P(AM-N)微球.采用傅里叶变换红外光谱(FTIR)、热重分析仪(TGA)、扫描电镜(SEM)、流变及岩心驱替实验对所合成微球的结构、形貌、性能以及封堵效果进行了表征与测试,并考察了溶胀时长、温度和不同盐溶液浓度对P(AM-N)微球性能的影响.测试结果表明,P(AM-N)微球的平均粒径为76.42 nm,溶胀5 d后P(AM-N)微球的膨胀率高达17.21倍;在70℃下,P(AM-N)微球老化2 d后溶胀率高达17.14倍,在20000 mg/L NaCl溶液和2000 mg/L CaCl_(2)溶液中分别溶胀3 d后膨胀率高达5.31倍和6.03倍,说明其具有较好的耐温性和抗盐性;在注入量为0.5%的条件下,P(AM-N)微球封堵率可达到97.98%,与P(AM)微球相比具有更好的封堵性且弹性增强.

甜菜碱型疏水缔合胶凝剂的制备及其性能评价

当前在碳酸盐岩酸化压裂改造中应用的主要添加剂(胶凝剂)逐渐不能满足储层改造的需要。为此,文中以N-甲基牛黄酸钠、烯丙基氯、棕榈酰氯和三乙胺为原料,在二氯甲烷溶剂中,通过两步法制备出一种含磺酸根离子和季铵盐的甜菜碱型疏水单体(TSM-16);并以TSM-16和丙烯酰胺(AM)为原料,采用自由基水溶液聚合法合成了一种新型胶凝剂(PAT),且与常规胶凝剂(PAA)进行了综合性能对比。结果表明,相较于PAA,由于PAT具有疏水链段和两性离子基团,它在酸液中表现出更优异的酸稳定性、热稳定性、剪切稳定性和缓速性能,在酸化压裂领域中具有良好的应用前景。