一种聚羧酸盐共聚物的合成及其助洗性能研究

以环氧琥珀酸(ESA)、丙烯酸(AA)、烯丙基磺酸钠(SAS)和丙烯酸羟丙酯(HPA)为原料,通过溶液聚合法合成了聚羧酸盐共聚物Poly(ESA-AA-SAS-HPA)。采用FT-IR,1H NMR,TG,DLS对其结构进行了表征。考察了螯合pH、温度及助剂质量分数等因素对Poly(ESA-AA-SAS-HPA)助洗性能的影响。结果表明:与三聚磷酸钠相比,其具有良好的助洗性能,鳌合量为308.7 mg/g、钙分散力为101.5 mg/g。同时,Poly(ESA-AA-SAS-HPA)与十二烷基苯磺酸钠(LAS)有良好的协同作用,可将体系表面张力降至45 mN/m。

基于水/辛酸异戊酯-白油反相乳液体系合成压裂液增稠剂及性能

反相乳液聚合过程中通常采用饱和烷烃的混合物白油作为分散介质,但是白油在使用过程中会存在污染环境的问题。本文以可降解化合物辛酸异戊酯替代了部分白油作为混合油相,丙烯酰胺(AM)和丙烯酰氧乙基三甲基氯化铵(DAC)为单体,通过反相乳液聚合法合成了W/O型聚丙烯酰胺-丙烯酰氧乙基三甲基氯化铵(P(AM-DAC)),通过~1H NMR、FT-IR和SEM对其结构进行表征。考察了乳化剂用量和辛酸异戊酯用量对预乳液稳定性、黏度和油-水界面张力的影响,引发剂用量和反应温度对P(AM-DAC)水溶液黏度的影响。结果表明:当乳化剂用量为10%,辛酸异戊酯用量为50%时,引发剂用量为0.8%,反应温度为38℃时,P(AM-DAC)水溶液黏度达到最大值,为129 mPa·s。考察了P(AM-DAC)与以白油作为油相合成的聚丙烯酰胺-丙烯酰氧乙基三甲基氯化铵(P(AM-DAC)-W)的性能对比,P(AM-DAC)和P(AM-DAC)-W的粘均分子量分别为5.019×10~6和5.045×10~6;质量分数为1%的水溶液黏度分别为129和132 mPa·s;当Na^(+)质量浓度为3000 mg/L时,1%的水溶液黏度分别为65和67 mPa·s;在90℃,170 s^(-1)剪切速率下持续剪切45 min后,1%的水溶液黏度分别为36.9和43.1 mPa·s;陶粒在1%的水溶液中的沉降速度分别为0.049和0.053 mm/s;破胶液表面张力分别为27.8和28.9 mN/m;残渣含量分别为1.63和1.76 mg/L。该研究表明辛酸异戊酯代替部分白油制备压裂液用增稠剂是可行的,不仅不影响增稠性能,而且对耐盐、耐温耐剪切、携砂、破胶和残渣含量等性能没有造成明显的影响。

笼型倍半硅氧烷聚合物/骨胶复合地膜的制备及性能

首先以八乙烯基笼型倍半硅氧烷(POSS-Vi)和乙烯基类单体为原料,采用自由基聚合法制备含有环氧基、酯基和羧基的多支化POSS聚合物;红外分析(FT-IR)、X射线衍射分析(XRD)和透射电镜(TEM)结果表明,POSS在聚合物中保持完整的笼型结构,直径在90 nm左右。然后采用POSS聚合物改性骨胶,制备POSS聚合物/骨胶复合薄膜,通过FT-IR、XRD和扫描电镜(SEM)对其结构形貌进行表征,同时考察了其作为地膜的相关性能。结果表明,POSS聚合物的环氧基与骨胶氨基发生了开环反应,改变了骨胶的非晶态结构。与骨胶膜相比,当POSS聚合物质量分数为25%时,复合薄膜的断裂伸长率提升了83.4%,在可见光区域的透光率平均降低了19.5%,水蒸气透过率下降了17.3%。其对土壤不仅能够起到保墒保温作用,而且在自然土壤中埋藏60 d即可降解82.98%。

Close-loop recyclable and flexible halide perovskite@wool keratin sensor with piezoelectric property

Halide perovskites with excellent piezoelectric properties,but their poor stability hinders their largescale application.Herein,a sandwich-structured halide perovskite flexible sensor with good stability was developed according to a three-step procedure as follows:(ⅰ) in-situ growth of wool keratinCsPbBr_(3)(WK-CsPbBr_(3)) using wool keratin in interfacial passivation and coating,(ⅱ) electrospinning of a wool keratin-CsPbBr_(3)/polyacrylonitrile(WCP) nanofiber film,and(ⅲ) coating of the WCP nanofiber with polydimethylsiloxane(PDMS) to obtain a sensor(WCPP).The sensor could generate a piezoelectric voltage of 7.8 V at a pressure of 6 kPa in the stages of pressing and releasing,and the output characteristics did not decline even after 10,000 cycles.Compared to the 4-month stability of the perovskite sensor,WCPP sensor exhibited the output performance even after 16 months,which indicated that wool keratin as a multidentate improved the stability of the halide perovskite.Additionally,the sensor displayed a self-cleaning property and could also light up 14 commercial LEDs.The close-loop recycling of the lead halide perovskite was achieved by dissolving the WCP nanofiber film in DMF and then reelectrospinning.Therefore,the method proposed is a step forward for achieving the commercialization of WK-CsPbBr_(3) and providing new avenues for further utilization of wool waste.

Janus纳米材料可控制备的研究进展

Janus纳米材料是指同一结构中含有2种不同化学组成或不同极性的非对称结构,尺寸一般为纳米级或微米级的各向异性结构材料,主要是通过化学改性或其他相互作用有序组装而形成。由于其特殊的结构和表面性能,可作为Pickering乳化剂、增溶剂、催化剂等而备受关注。文中归纳了Janus纳米材料的可控制备方法及特点和适用范围,包括:拓扑选择表面改性、诱导相分离、自组装和微流体技术等,并就Janus粒子的特殊结构带来的性能尤其是两亲性和界面增容性做以简述,最后就Janus纳米材料的发展提出了建议。

聚合物/铈掺杂纳米氧化锌复合材料的制备及性能

通过原位法将铈掺杂纳米氧化锌(Ce-ZnO)引入二甲基二烯丙基氯化铵(DMDAAC)与α-甲基丙烯酸(MAA)的共聚体系中,制备了P(DMDAAC-MAA)/(Ce-ZnO)复合材料。X射线衍射、红外光谱与透射电镜结果表明,复合材料形成了一种均匀的球型花状结构。将不同Ce-ZnO用量的复合材料应用于制革工艺中,考察了坯革的抗菌防霉性能与力学性能。应用结果表明,当Ce-ZnO用量为1.8%时,应用P(DMDAAC-MAA)/(Ce-ZnO)复合材料后坯革具有良好的抗菌性能以及较优的力学性能,但基本无防霉性能;结合扫描电镜与能谱分析结果可知,复合材料在坯革中均匀分散。

Ultra-low reflection electromagnetic interference shielding nanofiber film with effective solar harvesting and self-cleaning

It is urgent to develop low-reflection electromagnetic interference shielding material to shield electromagnetic waves(EMW)and reduce their secondary radiation pollution.Herein,an electromagnetic interference shielding nanofiber film is composed of ZnO and carbon nanofiber(CNF)via electrospinning and carbonization approachs,and subsequently coating perfuorooctyltriethoxysilane as a protective layer.On the one hand,ZnO coated by porous carbon,which is derived from ZIF-8,endows the nanofiber film low reflection property through optimizing impedance matching between free space and the nanofiber film.On the other hand,the nanofiber film possesses high electromagnetic interference shielding efficiency,which is beneficial by excellent electrical conductivity of CNF derived from waste leather scraps.Furthermore,the nanofiber film involves abundant interface,which contributes to high interfacial polarization loss.Thus,the nanofiber film with a thickness of 250 pm has electrical conductivity of 53 S/m and shielding efficiency of 50 dB.The reflection coefficient of the nanofiber film is inferior to 0.4 indicates that most of EMW are absorbed inside the materials and the nanofiber film is effective in reducing secondary radiation contamination of electromagnetic waves.Fortunately,the nanofiber film exhibits outstanding solar harvesting performance(106℃at 1 sun density)and good self-cleaning performance,which ensure that the nanofiber film can work in harsh environments.This work supplies a credible reference for fabricating low-reflection electromagnetic shielding nanofiber film to reduce secondary radiation pollution and facilitates the upcycling of waste leather scraps.