低表面能涂層材料因其特殊的潤濕與潤滑特性,在表面減阻防污、自清潔、防結冰等領域應用廣泛。中國科學院蘭州化學物理研究所固體潤滑國家重點實驗室表界面團隊多年來致力于低表面能自潤滑功能涂層研究,近期在該領域取得系列進展。
受豬籠草啟(qi)發的在多孔或納米結(jie)構(gou)表(biao)(biao)(biao)面(mian)(mian)中封存低表(biao)(biao)(biao)面(mian)(mian)能潤(run)滑(hua)(hua)(hua)劑(ji)(ji)的“超滑(hua)(hua)(hua)”材料近(jin)年來成為研究熱點。但這種“超滑(hua)(hua)(hua)”表(biao)(biao)(biao)面(mian)(mian)因存在納米結(jie)構(gou)表(biao)(biao)(biao)面(mian)(mian)耐(nai)磨性(xing)(xing)差,潤(run)滑(hua)(hua)(hua)劑(ji)(ji)分子(zi)通過弱范德華力吸附(fu)于表(biao)(biao)(biao)面(mian)(mian)從而(er)易(yi)損失(shi),導致耐(nai)久性(xing)(xing)差。針對(dui)這一問題,研究人員制(zhi)備(bei)了(le)(le)帶有“錨固”基團的潤(run)滑(hua)(hua)(hua)劑(ji)(ji)“刷”狀大分子(zi),將傳(chuan)統潤(run)滑(hua)(hua)(hua)劑(ji)(ji)分子(zi)通過化學鍵(jian)錨固于光滑(hua)(hua)(hua)表(biao)(biao)(biao)面(mian)(mian)。同時,引入無(wu)機中間(jian)層增加鍵(jian)合強度,大大提升了(le)(le)表(biao)(biao)(biao)面(mian)(mian)耐(nai)磨性(xing)(xing)和耐(nai)溶劑(ji)(ji)浸泡特(te)性(xing)(xing)。在100 kPa壓(ya)力下,往復摩(mo)擦3萬次(ci)表(biao)(biao)(biao)面(mian)(mian)潤(run)濕特(te)性(xing)(xing)幾乎保(bao)持不變;同時具(ju)有普適性(xing)(xing),在各種基底均可修飾(Prog.Org.Coat.,2021,154,106171)(圖1a-b)。
將聚(ju)(ju)硅(gui)氧烷(wan)鏈換成全氟(fu)聚(ju)(ju)醚鏈段,表(biao)面呈現出更加優異的耐沾污性和(he)耐磨性。在有機溶劑中用聚(ju)(ju)酯棉布(bu)對(dui)偶(ou)摩擦20萬次,潤濕性損失(shi)小于(yu)5%,耐沾污性幾乎保持不變(圖(tu)(tu)1c-d)。該文章近期作為封面文章發表(biao)在ACS Appl.Mater.Interfaces(2021,13,14562)(圖(tu)(tu)1e)上。
圖(tu)1“刷狀”分子(zi)接枝的自潤滑雙疏表面
受荷葉啟發的(de)(de)超(chao)疏水材(cai)料具有明顯防(fang)(fang)除冰(bing)(bing)效(xiao)(xiao)果,但在(zai)(zai)低(di)溫高濕度環(huan)境下(xia)(xia),超(chao)疏水防(fang)(fang)除冰(bing)(bing)效(xiao)(xiao)果喪失,而機(ji)(ji)械(xie)除冰(bing)(bing)會(hui)破(po)壞(huai)(huai)涂(tu)(tu)層(ceng)微結構(gou)進而破(po)壞(huai)(huai)其超(chao)疏水特性(xing)(xing)。針對(dui)這些問題,研究(jiu)人員(yuan)利(li)(li)(li)(li)用(yong)(yong)氟(fu)化(hua)碳納米(mi)管(guan)和工程化(hua)丙(bing)烯酸樹脂(zhi)制備超(chao)雙疏涂(tu)(tu)層(ceng),利(li)(li)(li)(li)用(yong)(yong)碳納米(mi)管(guan)可見光(guang)(guang)(guang)(guang)-熱(re)(re)(re)(re)(re)效(xiao)(xiao)果,實現(xian)了(le)該超(chao)雙疏涂(tu)(tu)層(ceng)在(zai)(zai)太陽(yang)光(guang)(guang)(guang)(guang)下(xia)(xia)的(de)(de)自主加熱(re)(re)(re)(re)(re)防(fang)(fang)冰(bing)(bing)、除冰(bing)(bing)。通過光(guang)(guang)(guang)(guang)熱(re)(re)(re)(re)(re)層(ceng)-導熱(re)(re)(re)(re)(re)層(ceng)-絕熱(re)(re)(re)(re)(re)層(ceng)的(de)(de)多層(ceng)設計,提(ti)升了(le)放熱(re)(re)(re)(re)(re)除冰(bing)(bing)效(xiao)(xiao)率,在(zai)(zai)太陽(yang)光(guang)(guang)(guang)(guang)照射涂(tu)(tu)層(ceng)部分區域即(ji)可實現(xian)全表(biao)面防(fang)(fang)除冰(bing)(bing),避免了(le)除冰(bing)(bing)時的(de)(de)機(ji)(ji)械(xie)破(po)壞(huai)(huai)(ACS Appl.Mater.Interfaces,2020,12,46981)(圖2a)。利(li)(li)(li)(li)用(yong)(yong)碳納米(mi)管(guan)的(de)(de)電(dian)(dian)熱(re)(re)(re)(re)(re)效(xiao)(xiao)應,賦予表(biao)面光(guang)(guang)(guang)(guang)熱(re)(re)(re)(re)(re)、電(dian)(dian)熱(re)(re)(re)(re)(re)復合“1+1>2”效(xiao)(xiao)果,實現(xian)了(le)涂(tu)(tu)層(ceng)白(bai)天(tian)利(li)(li)(li)(li)用(yong)(yong)光(guang)(guang)(guang)(guang)、夜晚(wan)利(li)(li)(li)(li)用(yong)(yong)電(dian)(dian)的(de)(de)全天(tian)候熱(re)(re)(re)(re)(re)防(fang)(fang)除冰(bing)(bing)(Adv.Mater.Tech.,2021,6,2100371)(圖2b)。為(wei)避免光(guang)(guang)(guang)(guang)熱(re)(re)(re)(re)(re)量損(sun)失,研究(jiu)人員(yuan)利(li)(li)(li)(li)用(yong)(yong)冰(bing)(bing)模板(ban)法(fa)制備了(le)大(da)孔(kong)狀超(chao)疏干凝(ning)膠,利(li)(li)(li)(li)用(yong)(yong)該材(cai)料多孔(kong)隔熱(re)(re)(re)(re)(re)性(xing)(xing)質(zhi),將光(guang)(guang)(guang)(guang)熱(re)(re)(re)(re)(re)量聚(ju)集于光(guang)(guang)(guang)(guang)輻(fu)照區域,大(da)大(da)提(ti)升了(le)材(cai)料光(guang)(guang)(guang)(guang)熱(re)(re)(re)(re)(re)性(xing)(xing)能,在(zai)(zai)-30℃環(huan)境下(xia)(xia),0.25倍太陽(yang)光(guang)(guang)(guang)(guang)下(xia)(xia)即(ji)可實現(xian)材(cai)料表(biao)面的(de)(de)永遠不結冰(bing)(bing)(ACS Appl.Mater.Interfaces2021,13,37609)(圖2c)。
圖(tu)2光/電超疏防冰涂層
相關技術獲(huo)中國發明專利授權(quan)ZL 201811398503.3、ZL 201810449961.9、ZL 202010505684.6和ZL 202110702491.4。
圖(tu)3當(dang)前主要防除冰材(cai)料策(ce)略
基于以(yi)上工作,受ACS Materials Letters期(qi)刊邀請(qing),該團隊撰(zhuan)寫了題為“Material Strategies for Ice Accretion Prevention and Easy Removal”的(de)綜(zong)述文章(ACS Mater.Lett.2022,4,246-262)(圖3)。從材料技(ji)術角度總結(jie)了被動(dong)防冰、主(zhu)動(dong)除冰及主(zhu)被動(dong)結(jie)合的(de)三種防除冰策略。
上(shang)述工作得(de)到了國家自(zi)然(ran)科(ke)學(xue)基金、甘肅省(sheng)、中國中車集團有限公司及煙臺中科(ke)先進材料與(yu)綠色化(hua)工產業技(ji)術研(yan)究(jiu)院等的支持。