【摘要】：鈣磷生物陶瓷是一類(lèi)主要由磷酸鹽組成的材料,在組成元素和結(jié)構(gòu)上與人體骨組織和牙的無(wú)機(jī)成分相近,具有優(yōu)良的骨傳導(dǎo)性和生物活性,廣泛應(yīng)用于硬組織修復(fù)和替換。鈣磷生物陶瓷材料可以制成塊狀、粉體和顆粒狀,以滿足不同應(yīng)用要求。球形顆粒因具有堆積密度高、流動(dòng)性好和不容易團(tuán)聚的優(yōu)點(diǎn),近年來(lái)受到更多關(guān)注。本文采用液滴-冷凝法制備鈣磷陶瓷球形多孔顆粒,對(duì)制備工藝進(jìn)行深入研究,通過(guò)改變材料組成和制備工藝參數(shù),實(shí)現(xiàn)不同尺寸和孔隙結(jié)構(gòu)的球形顆粒的可控制備。為降低鈣磷陶瓷的燒結(jié)溫度,在陶瓷漿料中加入無(wú)機(jī)鹽,在較低燒結(jié)溫度時(shí)形成低共熔相促進(jìn)燒結(jié)。加入以淀粉為主的有機(jī)添加劑,提高陶瓷漿料懸浮穩(wěn)定性,提高制備顆粒成分的均勻性,使制備工藝穩(wěn)定。二甲基硅油作為冷凝液具有比較合適的密度和粘度,可以使?jié){料液滴充分凝固；而正庚烷和苯甲醚作為冷凝液時(shí),由于其密度和粘度都較小,需要冷凝液有更高的液柱才能保證成形。浸泡顆粒模擬體液的pH變化在7-7.6的范圍內(nèi),在模擬體液中的顆�？梢猿蔀樘妓崃u基磷灰石(CHA)沉積的基底。而無(wú)機(jī)添加劑的加入,特別是硫酸鹽添加劑的加入可以促進(jìn)CHA的沉積。影響制備球形顆粒尺寸的因素包括漿料粘度、燒結(jié)溫度和裝置出口的內(nèi)徑,其中起決定性作用的因素是漿料出口的內(nèi)徑。對(duì)應(yīng)不同的出口內(nèi)徑,存在一個(gè)合適的漿料粘度,使用具有相對(duì)應(yīng)粘度的有機(jī)添加劑,可以穩(wěn)定地制備球形顆粒,過(guò)低或過(guò)高的漿料粘度,都會(huì)使成形工藝無(wú)法進(jìn)行。堿糊法制備的淀粉有機(jī)添加劑粘度變化范圍較大,改變其保溫的溫度可以提高粘度,便于制備2-3mm的球形顆粒；提高漿料中淀粉含量可以在較大范圍內(nèi)增大漿料的粘度,可用于制備3-5mm的球形顆粒。球形顆粒的孔隙主要來(lái)源于溶劑結(jié)晶升華留下的空間,顆粒中心區(qū)域以等軸狀孔隙為主,邊緣區(qū)域則是形狀不規(guī)則且孔徑較小的孔隙。通過(guò)控制漿料的冷凝溫度,可以得到具有不同孔隙率和孔徑的顆粒。-25℃冷凝得到的球形顆粒具有比較高的孔隙率以及合適的平均孔徑。燒結(jié)會(huì)使較高冷凝溫度(-15℃和-20℃)制備顆�？紫兜目讖綔p小,而使較低冷凝溫度(-25℃和-30℃)制備顆�？紫兜目讖皆黾�。添加炭粉作為造孔劑,一方面在液滴冷凝時(shí)會(huì)阻礙溶劑的結(jié)晶,但不會(huì)影響孔隙平均孔徑；另一方面,造孔劑燒失之后會(huì)在一定程度上改變顆粒的孔隙結(jié)構(gòu)。加入5%造孔劑制備顆粒的孔隙具有最大的平均孔徑,而加入10%造孔劑制備顆粒的孔隙具有最高的孔隙率。顆粒孔隙主要還是以較小的孔隙(小于21.43μm)為主,造孔劑的加入只會(huì)影響較大孔隙的形貌、數(shù)量和孔隙率。
[Abstract]:Calcium phosphorus bioceramic is a kind of material mainly composed of phosphate. It is similar to the inorganic composition of human bone tissue and teeth in composition elements and structure. It has excellent bone conductivity and biological activity and is widely used in hard tissue repair and replacement. Calcium phosphorus bioceramic materials can be made into bulk, powder and particles to meet different application requirements. Spherical particles have attracted more and more attention in recent years because of their high stacking density, good mobility and not easy agglomeration. In this paper, the spherical porous particles of calcium and phosphorus ceramics were prepared by droplet condensation method, and the preparation process was deeply studied. by changing the composition and preparation parameters of the materials, the controllable preparation of spherical particles with different sizes and pore structures was realized. In order to reduce the sintering temperature of calcium-phosphorus ceramics, inorganic salt was added to the ceramic slurry to form low eutectic phase to promote sintering at lower sintering temperature. Adding starch as the main organic additive can improve the suspension stability of ceramic slurry, improve the uniformity of preparation particle composition, and make the preparation process stable. Dimethyl silicone oil as condensate has more suitable density and viscosity, which can fully solidify the slurry droplets. When n-hexane and anisole are used as condensate, because of their low density and viscosity, higher liquid column is needed to ensure the formation of condensate. The pH of simulated body fluid changed in the range of 7 鈮，

本文編號(hào)：2479682