氩等离子体处理改性丙纶

探讨了改性丙纶经氩等离子体处理的工艺条件及处理后纤维的性能及表面形态。改性丙纶经氩等离子体处理后 ,失重率增大 ,回潮率增大 ,试样的回潮率为处理前的 14 0 %～ 40 0 % ,失重率 0 .3 5 %～0 .3 8%时回潮率最大。处理后丙纶表面产生较深的蚀点和凹槽。较佳的处理条件为时间 10min ,功率10 0W ,工作气体压力 5 0Pa。     

PET非织造布等离子改性及抗菌性能研究

采用低温氧等离子体处理聚对苯二甲酸乙二酯(PET)非织造布接枝丙烯酸(AA)后,再接枝壳聚糖,探讨了氧等离子体参数对接枝AA后PET亲水性的影响,以及接枝壳聚糖后其PET非织造布抗菌性能的变化。结果表明:低温氧等离子体处理PET非织造布后,其纤维表面粗糙度增加,接枝AA后PET亲水性提高。低温氧等离子体处理PET非织造布接枝AA改性的最佳条件为:工作压强30 Pa,放电功率40 W,处理时间2 min。接枝壳聚糖后,PET非织造布具有抑菌性能,对大肠杆菌和金黄色葡萄球菌有明显的抑菌效果。     

氩气等离子体处理对丙纶隔膜力学性能的影响

研究了应用氩气等离子体表面改性技术对丙纶非织造织物进行处理的技术,探讨了处理时放电功率、放电时间、反应压力等对丙纶非织造织物的力学性能的影响。结果表明,通过氩气等离子体表面活化处理,虽然会对无纺丙纶非织造物的力学性能造成影响,但是不会影响丙纶非织造物的使用。     

低温氩等离子体改善PTT织物吸湿性的研究

用氩低温等离子体对PTT织物进行表面改性,以提高PTT织物的吸湿性能。在不同等离子体处理工作参数(放电功率、放电时间、工作气压)下对PTT织物吸湿性变化进行了规律性和原理分析,并探讨等离子体对PTT织物的最佳处理工艺。实验结果表明:放电时间5min、放电功率200W、气体压强50Pa的处理条件使PTT织物得到最佳的吸湿性能;PTT织物的微观表面出现了明显的凹坑和裂纹,同时强力变化较小。     

介质阻挡放电等离子体对PP非织造布的改性

利用常压介质阻挡放电(DBD)设备,研究了工作气体、放电电压、处理时间、试样布置方式等对聚丙烯(PP)熔喷非织造布吸水率和处理效果均匀性的影响。结果表明:PP非织造布试样在90kV下用氩等离子体处理40s,吸水率达672%,在氩气中混入少量氧气(Ar/O2体积比为10/1),吸水率可提高至717%;试样吸水率随处理时间及放电电压的增加均提高,可以通过增大放电电压来有效地降低处理时间;随着DBD等离子体处理强度的增加,PP非织造布整体亲水性和表观均匀性均得到有效提高;试样布满放电区域有利于提高其吸水率和处理效果的均匀性。     

隔膜对镍氢电池大电流放电性能的影响及特性

通过测试和计算厚度、面密度、吸碱量、吸碱速率、表观密度、隔膜孔隙度及表面SEM形貌特征,对6种镍氢电池隔膜(3种氟化隔膜和3种磺化隔膜)的物理性能进行了综合对比,分析了由这6种隔膜制成的相同正、负极的SC3000镍氢电池在15, 20及30 A下的放电性能;同时结合电池的循环寿命与荷电保持率,筛选出最适于镍氢电池大电流放电的磺化隔膜FV3. 对电池大电流放电时隔膜所应具备的特性进行了概括总结,提出了一种评价隔膜特性对镍氢电池大电流放电性能影响的新方法,对动力型镍氢电池的研究与开发具有重要的参考价值.     

PP非织造布的生物大分子接枝改性

采用环氧型交联剂乙二醇二缩水甘油醚(EGDE)及生物大分子(壳聚糖或胶原蛋白)对氨气低温等离子体处理后的聚丙烯(PP)非织造布进行表面接枝改性,探讨了接枝反应条件及改性PP非织造布的染色性、亲水性及抗菌性能。结果表明:氨气低温等离子体处理后的PP非织造布表面产生了可参与接枝反应的活性基团;EGDE具有较好的交联效果,壳聚糖的接枝效果高于胶原蛋白,较佳的接枝反应条件为交联剂0.15 g,壳聚糖质量浓度12 g/L,反应温度45℃,反应时间8 h;壳聚糖接枝改性后PP非织造布的染色性、亲水性及抗菌性能均得到改善,其酸性染料上染率约49%,芯吸高度0.8 cm,对金黄色葡萄球菌及大肠杆菌的抗菌率分别达96.9%和93.4%。     

低温等离子体引发丙烯酸在PET纳米纤维膜上的接枝聚合

介绍了低温等离子体引发丙烯酸（AA）表面接枝聚合对聚苯二甲酸乙二醇酯（PET）纳米纤维薄膜的改性研究。实验探索了放电时间和放电功率对薄膜润湿性的影响,在真空度60 Pa、AA气体流量3 L/min条件下,放电功率75～150 W范围内,放电时间60 s和放电功率150 W、放电时间30~60 s范围内,处理后薄膜的水接触角均为0°,结果说明了此改性PET纳米纤维膜具有超亲水性。通过扫描电镜、红外和力学性能等测试讨论了接枝处理前后薄膜的形态及性能的变化。实验结果表明气相低温等离子体接枝处理后,薄膜的断裂伸长率和断裂强度有一定的增强。低温等离子体引发AA表面接枝PET纳米纤维薄膜的方法有望成为电纺PET纤维膜表面改性的有效手段,具有积极的应用价值。     

丙烯酰胺接枝海藻酸纤维的耐碱性研究

采用等离子体处理接枝共聚的方法对海藻酸纤维表面接枝丙烯酰胺,以改善纤维的耐碱性,利用红外吸收光谱和扫描电镜对改性纤维进行表征;探讨了等离子体处理纤维的工艺条件,研究了改性纤维的吸湿性和力学性能。结果表明:海藻酸纤维表面已接枝上丙烯酰胺;等离子体处理和接枝反应最佳工艺条件为:放电功率100 W,放电时间4 min,丙烯酰胺质量分数40%,接枝时间60 min。改性后的纤维碱溶解率为0.23%,吸湿性没有显著变化,但断裂强度提高。     

高分子纳米纤维非织造布的批量生产

<正>日本广濑制纸公司(高知县土佐市)已进行了高分子纳米纤维非织造布的批量生产。生产的非织造布的纤维尺寸比一般非织造布更细,可开发成安全性高的分隔膜,使非织造布真正进入二次电池分隔膜领域。该非织造布将替代现有的镍氢电池中非织造布制的分隔膜及锂离子二次电池中的分隔膜,     

低温等离子体对UHMWPE纤维的表面改性

运用自行研制的常压低温等离子体设备对超高相对分子质量聚乙烯(UHMWPE)纤维进行了表面处理,选用正交试验法通过润湿性测试优化出不同工作气氛下的工艺条件,采用强力测试、扫描电镜(SEM)和光电子能谱仪(XPS)分析了等离子体处理前后UHMWPE纤维的性能变化。结果表明,常压低温等离子体在Ar携带丙烯酸和Ar／O2的气氛下处理UHMWPE纤维,表面改性效果良好。特别是选用Ar／O2流量比100:1,处理速度为5．8 m／min,输出功率189 W,可满足连续化生产。     

Lignin–polypropylene composites. II. Plasma modification of kraft lignin and particulate polypropylene

Indulin kraft lignin and polypropylene were subjected to plasma treatments in a rotating electrodeless plasma reactor at 13.56 MHz radio frequency, with the goal of improving the strength properties of the composites made from these materials. It was shown that efficient surface modification could be achieved by these plasma treatments, avoiding long reaction times and large volumes of reactants for modification by conventional wet chemistry. SiCl₄‐plasma treatments of lignin at 100 and 200 W resulted in silicon implantation in the range of 4–10% that depended on the treatment time. However, the effect of power in the treatments was minimal, given that changes in silicon implantation were not observed for changes in this parameter. SiCl₄‐plasma treatment of polypropylene at 80 W, 1 and 10 min, resulted in silicon implantation in the order of 10–15%, for the two different treatment times, showing that low power and short treatment times were sufficient to significantly alter the polypropylene surface. However at high power (250 W), the longer treatment time of polypropylene apparently led to formation of oligohalosilanes. Other plasma treatments in the rotating reactor such as plasma‐induced copolymerization of acryloyl chloride on both lignin and polypropylene, and plasma‐state polymerization of acryloyl chloride on polypropylene under pulsing conditions, resulted in thin film depositions. Evaluation of composites from these treated materials is described in the next contribution (Part III) from this series. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1920–1926, 2004     

Plasma-modified polyethylene membrane as a separator for lithium-ion polymer battery

The surface of polyethylene (PE) membranes as a separator for lithium-ion polymer battery was modified with acrylonitrile (AN) using the plasma technology. The plasma-induced acrylonitrile coated PE (PiAN-PE) membrane was characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and contact angle measurement. The electrochemical performance of the lithium-ion polymer cell fabricated with the PE and the PiAN-PE membranes were also analyzed. The surface characterization demonstrates that the enhanced adhesion of the PiAN-PE membrane resulted from the increased polar component of surface energy for the PiAN-PE membrane. The presence of the PiAN induced onto the surface of the membrane via the plasma modification plays a critical role in improving the wettability and electrolyte retention, the interfacial adhesion between the electrodes and the separator, the cycle performance of the resulting lithium-ion polymer cell assembly. The PiAN-PE membrane modified by the plasma treatment holds a great potential to be used as a high-performance and cost-effective separator for lithium-ion polymer battery.     

Hierarchical self-assembly of tannic acid/diethylenetriamine on polypropylene for high-performance separator

In lithium-ion batteries (LIBs), separator is used to provide a barrier between the anode and cathode and provide freedom for the transport of lithium-ions, which serves a key function in inhibiting internal short circuit and improving the battery safety. The limited wettability of commercial polyolefin separators in electrolytes restricts its utilization in extreme environmental conditions. In our work, we choose polypropylene (PP) as the precursor and can address the issue of poor wettability through suitable modification methods. Tannic acid (TA) and diethylenetriamine (DETA) were utilized to coat PP separator via hierarchical self-assembly approach, and the coating is further stabilized by taking advantage of the specific oxidizing properties of sodium periodate. This method scarcely increases the separator thickness or sacrifices the microporous structure of the original separator. The improved separator not only exhibits outstanding wetting capability and relatively high ion conductivity (1.24 mS cm⁻¹), but also has the highest lithium-ion migration number of 0.74. This indicates that when the modified separator is applied to LIBs, its electrochemical performance is significantly enhanced. The enhancement in electrochemical performance of LIBs is attributed to the strong absorption and retention ability of the coating on the separator. The reversible capacity of Li/PP-TD2 separator/LiFePO₄ battery is 144.3 mAh g⁻¹ at 2C, which is higher than that of PP separator (117.1 mAh g⁻¹) under the same current density. Even after 200 cycles, the PP-TD2 separator with two-layer assembly modification still maintains a higher coulombic efficiency of 97.55% and a discharge capacity of 96.6%. This hierarchical self-assembly modification of PP provides an effective approach for fabricating high-performance separator.     

聚丙烯结晶度对锂电池隔膜硬弹性的影响

通过对某锂电池隔膜生产企业所用不同批次聚丙烯(PP)原料进行检测,结合该企业的使用情况,对PP高结晶度有利于锂电池隔膜硬弹性提高的结论进行验证。实验结果表明,相同工艺条件下,高结晶度PP原料对于膜坯硬弹性性能没有明显提高,PP结晶度提高与膜坯硬弹性性能提高没有明显关联。在一定的条件下,膜坯硬弹性随原料结晶度提高有降低的趋势。     

聚乙烯醇交联改性聚乙烯锂离子电池隔膜的制备

将聚乙烯(PE)隔膜用乙醇润湿,然后将其放入聚乙烯醇(PVA)溶液中浸润,使PVA进入隔膜孔结构中,再将隔膜放入交联溶液[pH=2,25%(w)戊二醛]中进行交联反应,制备了PVA交联改性PE隔膜。采用傅里叶变换红外光谱和能量色散X射线光谱对隔膜的表面与断面进行了表征,并研究了改性隔膜的物理性能及电池性能。结果表明:PVA交联改性PE隔膜的表面亲水性和抗高温热收缩性提高,瞬时水接触角由初始的98.6°降至66.5°,且组装的锂离子电池的循环性能和倍率容量均有一定程度的改善,PE隔膜的离子电导率由0.463 mS/cm升至0.864 mS/cm。     

Kevlar织物的Ar等离子体表面改性工艺优化研究

本文采用正交试验设计的方法优化了Ar冷等离子体对Kevlar49 S500织物的表面改性工艺。研究了Ar冷等离子体处理工艺的气压、功率和处理时间等参数对Kevlar49 S500织物表面性质的影响,通过测定改性前后织物与环氧树脂复合的界面剪切强度,对处理效果进行评价。结果表明：工作气体压力的影响最显著,时间和功率的影响次之。最终获得了等离子体改性的最佳工艺条件70Pa、300W、2min,经该工艺处理后的Kevlar织物／环氧复合材料的层间剪切强度为40.8MPa,较未处理的34.6MPa提高了18％。     

Surface modification of graphite encapsulated iron nanoparticles by plasma processing

The graphite encapsulated iron nanoparticles were fabricated by using arc discharge method. The synthesized nanoparticles were pre-treated by an inductively-coupled RF Ar plasma and then post-treated by NH₃ plasma under various gas pressures and treatment times. Analyses of XPS spectra have been carried out to study the effect of the plasma treatment on the surface modification of nitrogen-containing groups. The morphological changes of the particles surface by plasma treatment have also been analyzed by using HR-TEM. Present results show that the highest values of N/C atomic ratio of 5.4 % is obtained by applying 10 min of Ar plasma pre-treatment and 2 min of NH₃ plasma post-treatment conducted in RF power of 80 W and gas pressure of 50 Pa.     

Preparation of 4A zeolite coated polypropylene membrane for lithium-ion batteries separator

This study aims to improve wettability and thermal resistance of lithium-ion batteries separators. For this purpose, a commercial polypropylene (PP) separator was coated by 4A zeolite using poly(vinylidene fluoride) as binder and effects of the separators' zeolite content was investigated. All the coated separators showed lower contact angles, higher electrolyte uptakes, and less thermal shrinkages compared to the neat commercial separator. The coated PPA8 separator (zeolite to binder ratio of 8) showed the lowest wettability (contact angle of 0°) and electrolyte uptake (270%) due to its surface porosity resulting from the zeolite particles interstitial cavities as well as their internal cavities. Also, the PPA8 separator ion conductivity was found as 2.25 mS cm⁻¹ and C-rate and cycling performance of its assembled battery were higher compared to those of the commercial PP separator assembled battery. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47841.