發(fā)布時(shí)間：2018-03-30 03:35

  本文選題：金紅石晶須　切入點(diǎn)：熔鹽法　出處：《河南科技大學(xué)》2017年碩士論文

【摘要】：陶瓷/聚合物復(fù)合材料作為柔性基板具有高機(jī)械彈性、低介電常數(shù)、低介質(zhì)損耗、高熱導(dǎo)率、低熱膨脹系數(shù)等優(yōu)異性能。陶瓷晶須具有優(yōu)異的物理化學(xué)性能,相對(duì)于陶瓷顆粒能進(jìn)一步提高復(fù)合材料的介電性能、熱學(xué)性能、力學(xué)性能和摩擦性能等。本實(shí)驗(yàn)分別把金紅石晶須、微米顆粒和納米顆粒及其改性后粉體加入107硅橡膠中經(jīng)室溫固化制備了復(fù)合材料,系統(tǒng)的研究金紅石形態(tài)和體積分?jǐn)?shù)及改性對(duì)復(fù)合材料微波介電性能的影響。金紅石晶須采用熔鹽法制備,以無(wú)定形Ti O2、ZnSO4·7H2O和Na2SO4按照1:1:1摩爾比混合為原料,加熱方式分別采用常規(guī)加熱和微波加熱,通過(guò)設(shè)計(jì)合理的實(shí)驗(yàn)方案研究加熱溫度,升溫速率和保溫時(shí)間對(duì)金紅石晶須形貌的影響。在微波加熱條件下,以升溫速率15℃/min,煅燒溫度700℃保溫15min,合成了形貌良好的金紅石晶須,其直徑約0.5μm,長(zhǎng)徑比約為25,與常規(guī)加熱相比加熱溫度降低了100℃,保溫時(shí)間由4h縮短到15min,這是由于微波加熱能對(duì)材料進(jìn)行整體而均勻的加熱。隨著金紅石填料體積分?jǐn)?shù)的增加,復(fù)合材料的εr和τf逐漸增大,Q×f逐漸減小。在同等體積分?jǐn)?shù)下,金紅石晶須/硅橡膠復(fù)合材料的εr略大,納米顆粒次之,微米顆粒最小;對(duì)于Q×f,在相同添加量下,金紅石晶須/硅橡膠復(fù)合材料的最大,其次是微米顆粒,納米顆粒最小;這可能與金紅石填料的不同形態(tài)有關(guān)。金紅石粉體用KH570改性后,三種復(fù)合材料的εr和Q×f均得到提高,當(dāng)金紅石填料體積分?jǐn)?shù)為19%時(shí),改性金紅石晶須/硅橡膠復(fù)合材料的εr=3.645,Q×f=3655GHz,τf=+45.6ppm/℃。實(shí)驗(yàn)把復(fù)合材料在1MHz和微波頻率下的εr試驗(yàn)值分別與Lichtenecker模型、Maxwell-Garnet模型和Jayasundere-Smith模型進(jìn)行了比較。發(fā)現(xiàn)在1MHz下,復(fù)合材料的εr試驗(yàn)值與三種模型的理論值基本相符,在微波頻率下,試驗(yàn)值比理論值偏低,隨著金紅石填料體積分?jǐn)?shù)的增大,偏差越來(lái)越大,與Maxwell-Garnet模型最為接近。同時(shí)還研究了復(fù)合材料的吸水率對(duì)其微波介電性能的影響。隨著浸泡時(shí)間的增加,復(fù)合材料的吸水率越來(lái)越大。在相同浸泡時(shí)間下,金紅石晶須/硅橡膠復(fù)合材料的吸水率最大,納米顆粒次之,微米顆粒最小。在微波頻率下,隨著復(fù)合材料吸水率的增加,復(fù)合材料的εr基本沒(méi)有變化,Q×f逐漸減小。
[Abstract]:As a flexible substrate, ceramic / polymer composites have excellent properties such as high mechanical elasticity, low dielectric constant, low dielectric loss, high thermal conductivity and low thermal expansion coefficient. Compared with ceramic particles, the dielectric properties, thermal properties, mechanical properties and friction properties of composites can be further improved. The composite materials were prepared by adding micron particles and nano-particles and their modified powders into 107 silicone rubber at room temperature. The effects of morphology and volume fraction of rutile and modification on microwave dielectric properties of composites were systematically studied. Rutile whiskers were prepared by molten salt method and mixed with amorphous TIO _ 2O _ 2ZnSO _ 4 7H2O and Na2SO4 at 1:1:1 molar ratio. The effects of heating temperature, heating rate and holding time on the morphology of rutile whisker were studied by designing a reasonable experimental scheme. Rutile whiskers with good morphology were synthesized at the heating rate of 15 鈩，

本文編號(hào)：1684173