本文關鍵詞： 聚苯乙烯微球 化學鍍 聚苯乙烯/鎳 核殼結構 中空微球　出處：《濟南大學》2011年碩士論文　論文類型：學位論文

【摘要】：隨著納米科學的發(fā)展,納米多孔材料作為一個重要的研究方向,已經成為了材料科學研究的焦點。由于該多孔材料具有納米級的孔徑,大的孔隙率,顯著的表面效應及高的比表面積,成為了一種新型的兼具功能和結構雙重屬性的性能優(yōu)異的材料,被廣泛地應用于環(huán)保清潔、高效節(jié)能等綠色材料,高效過濾及分離材料,燃料電池、消聲、減振材料,電磁屏蔽性材料,催化材料等各個領域。目前制備金屬納米多孔材料的方法很多,主要有金屬粉體燒結法、脫合金法、斜入射沉積法、膠體晶模板法等。本論文提出了一種新的方法制備有機/無機納米復合材料及納米金屬中空微球,通過對實驗條件的優(yōu)化,分別制得了鍍層均勻的納米復合材料和孔徑均一的中空微球。 本文首先采用微乳液聚合法制備了形貌可控的120 nm左右的聚苯乙烯微球,研究了單體用量、反應溫度及引發(fā)劑、乳化劑用量對聚苯乙烯微球粒徑及分布的影響,實驗測得聚苯乙烯微球的平均粒徑隨單體用量和引發(fā)劑用量的增加而增大,隨乳化劑濃度的增大和反應溫度的升高而減小,實驗室條件下測得制備聚苯乙烯微球的最佳配比條件為:單體苯乙烯10 mL,引發(fā)劑過硫酸鉀0.25 g,乳化劑十二烷基磺酸鈉0.4 g,反應介質水90 mL,水浴反應溫度75℃,反應時間8 h;然后采用化學鍍法,以聚苯乙烯微球為基體,分別用傳統(tǒng)的有鈀活化法和新的無鈀活化工藝對其進行前處理,使聚苯乙烯微球表面植入催化活性中心,制備了具有可控殼層的鎳包覆聚苯乙烯微球的核殼結構復合微球,優(yōu)化了化學鍍工藝,同時對兩種方法所制備的復合微球進行SEM、EDS、紅外光譜分析,由實驗結果可得,與傳統(tǒng)的有鈀活化工藝鍍鎳法相比,無鈀活化工藝鍍鎳法制得的PS/Ni復合微球分散性較好,且鍍層較均勻、較厚;然后論文根據復合微球的分解溫度范圍,在500℃下保溫5 h除去聚苯乙烯微球模板,制得了壁厚大約為15-20 nm,孔徑為100-130 nm的中空微球,并研究了不同燒失溫度對材料孔結構的影響,對最佳燒失溫度下制得的納米金屬鎳中空微球試樣進行了X射線衍射分析和N2吸附-脫附分析,結果表明,納米鎳中空微球試樣具有面心立方結構,且晶型很好,基本沒有引進其他雜質,通過BET吸附測得納米金屬鎳中空微球的比表面積為161.69 m~2·g~(-1)。論文選用液相催化加氫法,將制得的金屬鎳中空微球用于催化2,4-二甲基硝基苯加氫制備2,4-二甲基苯胺,結果表明,該多孔材料對2,4-二甲基硝基苯加氫反應有催化作用,但是選擇性和催化活性均不理想,在實驗室條件下,溫度為50℃,壓力為3.0 MPa,恒溫反應120 min,測得2,4-二甲基苯胺的收率為46 %,并初步探討了催化加氫反應機理。
[Abstract]:With the development of nanoscience, nano-porous materials, as an important research direction, have become the focus of material science, because the porous materials have nanometer pore size and large porosity. Because of its remarkable surface effect and high specific surface area, it has become a new type of material with dual properties of function and structure, which has been widely used in green materials such as environmental protection, clean, high efficiency and energy saving. High efficiency filtration and separation materials, fuel cells, noise suppression, vibration absorption materials, electromagnetic shielding materials, catalytic materials and other fields. At present, there are many methods to prepare metal nano-porous materials, mainly metal powder sintering method. In this paper, a new method was proposed to prepare organic / inorganic nanocomposites and nanometallic hollow microspheres by optimizing the experimental conditions. Nanocomposites with uniform coating and hollow microspheres with uniform pore size were prepared respectively. In this paper, polystyrene microspheres with controllable morphology were prepared by microemulsion polymerization. The amount of monomer, reaction temperature and initiator were studied. The effect of emulsifier dosage on the particle size and distribution of polystyrene microspheres was studied. The experimental results showed that the average particle size of polystyrene microspheres increased with the increase of the amount of monomer and initiator. With the increase of emulsifier concentration and reaction temperature, the optimum conditions for preparing polystyrene microspheres were determined as follows: monomer styrene 10 mL. The initiator potassium persulfate 0.25 g, emulsifier 12 alkyl sulfonate 0.4 g, reaction medium 90 mL water, water bath temperature 75 鈩，

本文編號：1476163