紀振冰，萬熠，趙梓賀，于明志，王宏衛(wèi)，范世緣

水熱溫度和時間對3D打印Ti-6Al-4V植入體表面理化性能的影響

紀振冰1，萬熠1，趙梓賀1，于明志1，王宏衛(wèi)2，范世緣1

（1.山東大學(xué) a.高效潔凈機械制造教育部重點實驗室 b.機械工程學(xué)院，濟南 250061；2.山東大學(xué)齊魯醫(yī)院 a.急診科 b.山東大學(xué)急危重癥臨床醫(yī)學(xué)研究中心，濟南 250012）

研究在具有微納米雙級結(jié)構(gòu)的3D打印鈦合金植入體表面制備聚多巴胺涂層的最佳工藝及參數(shù)。對酸蝕和陽極氧化處理后的3D打印Ti-6Al-4V樣品進行水熱處理，通過水熱法將聚多巴胺添加到樣品表面，并分析不同水熱溫度和時間的處理效果。使用掃描電子顯微鏡、三維共聚焦激光顯微鏡、X射線光電子能譜儀、接觸角測量儀、電化學(xué)工作站對各組樣品的表面形貌、粗糙度、元素組成、表面潤濕性、耐腐蝕性等進行表征。經(jīng)過酸蝕和陽極氧化處理后，在3D打印鈦合金植入體表面成功制備了微納米雙級結(jié)構(gòu)，表面納米管的管徑為80 nm左右，水熱處理后各組表面均可以觀察到有涂層附著。樣品表面元素分析結(jié)果表明，各組樣品表面的N/C值均與理論值0.125接近，證明水熱處理成功在微納米結(jié)構(gòu)表面添加了聚多巴胺涂層。隨著水熱處理溫度的升高和時間的延長，納米管的管徑逐漸減小，由80 nm減小至40 nm左右。隨著反應(yīng)時間的延長，樣品表面粗糙度逐漸降低，各組粗糙度均保持在4～5 μm，且接觸角逐漸減小，酸蝕后的表面接觸角為52.1°，陽極氧化后，接觸角降低至42.9°。經(jīng)過水熱處理，各組接觸角均小于35°，表現(xiàn)出較好的親水性。相比于酸蝕組和陽極氧化組，水熱處理后的各組的耐腐蝕性均得到增強。在基本保留原有微納米雙級結(jié)構(gòu)的前提下，37 ℃的反應(yīng)溫度和24 h的反應(yīng)時間適用于聚多巴胺在鈦合金植入體表面的沉積。研究結(jié)果為聚多巴胺在鈦合金植入體表面自聚合的工藝參數(shù)優(yōu)化提供了參考。

3D打??；鈦合金；植入體；水熱處理；微納結(jié)構(gòu)；聚多巴胺涂層

3D打印可以以計算機設(shè)計模型為基礎(chǔ)，進行逐層打印，實現(xiàn)復(fù)雜模型的制備[1]。作為一種加工效率較高、能夠用于復(fù)雜結(jié)構(gòu)制造的生產(chǎn)方法，3D打印正在逐漸應(yīng)用于植入體的制備中，并得到了眾多學(xué)者的關(guān)注[2-4]。鈦及其合金因具有良好的耐腐蝕性、較低的彈性模量和較好的力學(xué)性能，被廣泛應(yīng)用于臨床植入手術(shù)中[5-7]。然而，3D打印制備的鈦植入體具有生物惰性，表面質(zhì)量較差，植入后難以與周圍骨組織發(fā)生良好的骨結(jié)合[8]。為提高3D打印鈦植入體的生物活性，需要進行表面改性處理，以增強鈦與周圍組織的骨整合[9-11]。

目前，鈦植入體的表面改性處理主要集中在表面形貌改性和生物活性涂層改性[12-14]。3D打印制備的鈦植入體表面具有微米級形貌，無需進行微米級表面改性[15]，而鈦植入體表面的微納米雙級結(jié)構(gòu)可以促進成骨細胞的粘附、增殖和礦化[16-18]。研究表明，鈦植入體表面構(gòu)建的分級微納米結(jié)構(gòu)可以顯著增強細胞成骨相關(guān)基因的表達，并促進動物體內(nèi)新骨的形成[19]。聚多巴胺在促進細胞粘附、增殖[20-22]、降低細胞毒性[23]等方面具有較好的表現(xiàn)，已被廣泛應(yīng)用于提高鈦植入體的生物相容性。Hu等[24]通過水熱處理，在Ti-6Al-4V表面制備了PDA/GO/ZnO納米復(fù)合涂層，樣品具有良好的潤濕性和抗菌活性。在鈦植入體微納米結(jié)構(gòu)表面添加聚多巴胺涂層成為了新的研究熱點。He等[25]通過堿熱處理在鈦表面構(gòu)建了納米結(jié)構(gòu)，而后將植入體依次浸入多巴胺和硫酸銅溶液中，改性后的樣品具有良好的抗菌性能。Yan等[26]將陽極氧化后的鈦依次浸入多巴胺溶液和IL-4溶液中，成功在鈦表面制備了TiO2/PDA/IL-4復(fù)合涂層，樣品可以誘導(dǎo)巨噬細胞向抗炎M2表型極化。

目前，多巴胺聚合的最佳時間并不確定，從幾個小時[27]到24 h[28]不等。Zhou等[29]將純鈦分別在25、37、60 ℃下浸入聚多巴胺溶液中，以比較聚多巴胺在不同溫度下在鈦植入體表面的沉積效果。當(dāng)前研究中，用于聚多巴胺在具有微納米雙級結(jié)構(gòu)的3D打印鈦合金植入體表面涂覆的最佳工藝參數(shù)沒有得到深入討論。水熱法作為一種操作簡單、對環(huán)境污染較小的處理方法，被廣泛應(yīng)用于表面改性處理[30-32]。文中研究首先對3D打印鈦合金植入體進行酸蝕處理，而后進行陽極氧化，通過水熱法在鈦合金表面自聚合生成聚多巴胺涂層，研究在不同溫度和時間下，聚多巴

胺與具有微納米雙級結(jié)構(gòu)的3D打印鈦合金植入體的結(jié)合效果及其對表面性能的影響。采用掃描電子顯微鏡、三維共聚焦激光顯微鏡、接觸角測量儀、X射線光電子能譜儀、電化學(xué)工作站等對不同組樣品的表面理化性能進行了表征。

1 試驗

1.1 材料預(yù)處理

Ti-6Al-4V樣品由3D Systems公司的MDP Prox320激光打印機制造，粉末直徑為10～53 μm，激光功率為88 W，掃描速度為620 mm/s。鈦合金樣品尺寸為10 mm×10 mm×1 mm，打印后的樣品在丙酮、乙醇、去離子水中依次超聲清洗15 min。將干燥后的樣品置于2%（質(zhì)量分數(shù)）的氫氟酸溶液中腐蝕5 min，所得樣品記為AE。將酸蝕后的樣品置于NH4F-丙三醇的水溶液中（體積比為1∶1），鈦片連接恒壓電源的正極，鉑片連接恒壓電源的負極，在25 V的電壓下陽極氧化1 h，實驗裝置如圖1所示，所得樣品記為AN。將陽極氧化后的樣品分別在37、60 ℃的2 mg/mL鹽酸多巴胺的Tris-HCl緩沖溶液（pH=8.5）中分別水熱處理8、16、24 h，而后在去離子水中進行超聲清洗，以去除表面結(jié)合較弱的聚多巴胺分子，并在空氣中干燥，所得樣品分別記為AL1、AL2、AL3、AH1、AH2、AH3，見表1。反應(yīng)過程如圖2所示。

圖1 陽極氧化實驗裝置

表1 樣品縮寫

Tab.1 Abbreviations of samples

圖2 反應(yīng)過程

1.2 樣品表面表征

使用掃描電子顯微鏡（SEM，JSM-7610F，日本）對樣品表面形貌進行觀察與表征。通過三維共聚焦激光顯微鏡（3D-LSM，VK-X200K，Keyence，日本）對樣品三維形貌及表面粗糙度a進行測量及表征。通過X射線光電子能譜儀（XPS，AXIS Supra，英國）對樣品表面元素進行定性及定量分析。

1.3 表面潤濕性分析

通過接觸角測量儀（SL200KS，美國）對樣品表面的潤濕性進行分析，將2 μL去離子水滴在樣品表面，通過測量接觸角的大小判斷樣品表面的親水性。

1.4 電化學(xué)腐蝕試驗

通過電化學(xué)工作站使用動電位掃描法對樣品的耐腐蝕性進行檢測。電化學(xué)工作站由飽和甘汞電極（參比電極）、鉑電極（輔助電極）和試樣（工作電極）構(gòu)成三電極系統(tǒng)。樣品通過銅線與工作電極相連接，樣品的工作面積為1 cm2，非工作面積通過環(huán)氧樹脂進行絕緣封裝。電化學(xué)工作體系置于37 ℃恒溫的0.9% NaCl溶液中，設(shè)置初始電位為–0.8 V，終止電位為2 V，掃描速率為2 mV/s。

2 結(jié)果和討論

2.1 樣品表面表征

樣品表面形貌對植入體的生物相容性和與周圍組織結(jié)合的能力有著十分重要的作用。在不同倍數(shù)掃描電鏡下觀察到的樣品表面形貌如圖3所示。在低倍鏡下，AE組樣品表面可以觀察到峰–谷狀的微結(jié)構(gòu)，AN組表面在酸蝕后，表面銳邊變得更平滑，AL1—AH3各組樣品的表面形貌大致相同，具有微米級的溝壑結(jié)構(gòu)，同時表面觀察到有涂層附著。在高倍鏡下可以發(fā)現(xiàn)，AE組表面出現(xiàn)了微米級的凹坑，這些微米級結(jié)構(gòu)被認為有利于提高植入體與周圍組織的剪切強度[33]，陽極氧化后，AN組表面在原凹凸不平的表面上生成了有序排列的TiO2納米管陣列，形成了微納米雙級結(jié)構(gòu)。對于AL1—AH3組，當(dāng)反應(yīng)時間相同時，隨著溫度的升高，試件表面物質(zhì)團聚的現(xiàn)象越來越明顯。AL1組納米管直徑在80 nm左右，而AH各組相比于AL組，納米管的管徑明顯減小。隨著時間的延長，涂層的厚度逐漸增大，AL各組之間和AH各組之間均發(fā)現(xiàn)納米管的管徑隨時間的延長而逐漸變小，AH3組納米管管徑減小至40 nm左右，且納米管之間的間隙逐漸減小，被涂層所填充，甚至可以觀察到有些納米管出現(xiàn)被堵塞的情況。以上結(jié)果表明，反應(yīng)時間的延長和溫度的升高會使反應(yīng)更加充分，生成的涂層也更加致密，在溫度較高和反應(yīng)時間較長時，甚至可以覆蓋試件表面原有的微納米結(jié)構(gòu)。由圖3可知，AL3組表面形成的涂層較均勻，并較大程度地保留了表面原有的微納米雙級結(jié)構(gòu)。

陽極氧化是在基于氟化物的電解液中，將鈦作為陽極，并施加恒定電壓，在鈦表面生成二氧化鈦納米管的過程[34]，與其他方法相比，該方法效率較高，且納米管管徑和長度可控[16]。在陽極氧化的過程中，鈦與電解液在電場的作用下發(fā)生反應(yīng)，生成二氧化鈦層，二氧化鈦層會阻礙電化學(xué)反應(yīng)的進行。此時，二氧化鈦會與水中的F–發(fā)生反應(yīng)，生成水溶性的[TiF6]2–，暴露出原有的鈦基底，在溶解和生成的動態(tài)循環(huán)中形成緊密排列的納米管，并隨著時間的延長，納米管逐漸向基體延伸，從而使納米管的長度逐漸增大，反應(yīng)方程式見式（1）、（2）[35-37]：

Ti+2H2O→TiO2+4H++4e–(1)

TiO2+6HF→[TiF6]2-+2H2O+2H+(2)

各組試件的三維形貌如圖4所示。從圖4可以看出，試件表面均可以觀察到3D打印過程中激光熔融的痕跡，陽極氧化后，AN組表面的棱角變得更平滑。采用不同參數(shù)進行水熱處理后的樣品表面未觀察到明顯差異，這與低倍鏡下掃描電鏡觀察結(jié)果相一致。

經(jīng)過處理之后樣品的粗糙度如圖5所示，各組粗糙度均保持在4～5 μm。其中，酸蝕組的表面粗糙度為4.905 μm，陽極氧化后樣品的表面粗糙度降低至4.422 μm，AL1組由于在37 ℃的條件下進行，且反應(yīng)時間較短，表面仍較大程度地保留著原有的微納米形貌，表面粗糙度為4.633 μm，而AL2、AL3組由于反應(yīng)時間較長，在樣品表面形成了較均勻的涂層，粗糙度分別降低至4.438、4.130 μm。同時，在60 ℃的反應(yīng)溫度下，樣品表面粗糙度略有提升，分析原因是反應(yīng)速率加快使表面涂層出現(xiàn)團聚現(xiàn)象。AH1組經(jīng)過8 h的反應(yīng)后，粗糙度為4.758 μm，且隨著反應(yīng)時間的延長，粗糙度逐漸降低。AH2、AH3組的粗糙度分別為4.601、4.239 μm。這種現(xiàn)象可以歸因于表面自組裝方法的特性，隨著時間的延長，表面分子將呈現(xiàn)更加均勻的分布，可以降低表面的粗糙度[38]。有研究表明，粗糙度a為3～5 μm的表面可以增加骨與植入體之間的接觸面積[39-40]，有利于細胞的粘附、礦化、相關(guān)基因的表達及骨整合[41-43]。

圖3 各組試件的表面SEM形貌

圖4 各組樣品表面的三維形貌

2.2 表面元素分析

使用XPS分析樣品表面元素組成，各組樣品的XPS全譜圖如圖6所示。由全譜圖可以看出，由于鈦的化學(xué)性質(zhì)較活潑，極易與空氣中的氧氣反應(yīng)，因此酸蝕組表面可以檢測到較強的Ti2p峰和O1s峰。陽極氧化后，表面可以檢測到酸蝕組表面沒有的F1s峰。經(jīng)過水熱處理之后，各組在400.1 eV處均出現(xiàn)了N1s峰，且樣品表面碳和氧的含量較高，證明在鈦基底表面添加了聚多巴胺涂層。在37 ℃下對樣品進行處理時，樣品表面可以檢測到較弱的F1s峰和Ti2p峰，證明經(jīng)過陽極氧化，表面仍然有殘留的[TiF6]2–。在60 ℃下，隨著反應(yīng)溫度的升高，多巴胺聚合的速率加快，樣品表面的聚多巴胺涂層較致密，使得原有的F1s峰和Ti2p峰消失。通過表2數(shù)據(jù)計算可知，各組的N/C值均與理論值0.125接近，表明經(jīng)過水熱處理后在樣品表面成功添加了聚多巴胺涂層[44-45]。隨著溫度的升高，N/C值逐漸降低，且AL3組與AH3組大致相同，隨著時間的延長，AL各組的N/C值先增大、后減小，AH各組的N/C值先減小、后增大，而AH各組N/C值相比于AL組，距離理論值差距較大。溫度較高時，在反應(yīng)過程中可能存在溶液中的雜質(zhì)等參與反應(yīng)的現(xiàn)象，造成其他非目標產(chǎn)物的生成。

圖5 不同樣品表面的粗糙度平均值（n=3）

圖6 各組樣品表面的XPS全譜圖

表2 各組樣品表面元素含量分析結(jié)果

Tab.2 Surface element content analysis results of different groups

目前，因為聚多巴胺的形成過程復(fù)雜，其形成機理尚未明確。有學(xué)者認為，PDA的形成為單純的化學(xué)聚合，即直接氧化聚合。多巴胺首先被氧化生成多巴胺醌，分子內(nèi)環(huán)化，氧化成無色多巴色素，形成5,6–二羥基吲哚，并進一步氧化成5,6–二羥基吲哚醌。之后發(fā)生分支反應(yīng)，產(chǎn)生二聚體的多種異構(gòu)體。隨后在更高的低聚物上發(fā)生分支反應(yīng)，然后這些低聚物進一步發(fā)生自聚合反應(yīng)，生成小于100 nm的聚多巴胺顆粒，氧化過程如圖7所示[46-48]。

由于PDA的形成機制較為復(fù)雜，不同文獻對PDA聚合的機理提出了不同的解釋。其中，Hong等[49]從物理和化學(xué)的角度對PDA的聚合過程提出了解釋，得到了許多學(xué)者的認可，反應(yīng)過程如圖8所示。首先，多巴胺在氧氣的參與下被氧化為多巴胺醌，這一過程已得到學(xué)者們的公認。另外，結(jié)合多巴胺在聚合過程中膜層的顏色和狀態(tài)的變化，推測多巴胺在聚合過程中發(fā)生了類似黑色素的聚合過程，同時表面形成的膜層阻礙了氧氣的進入，從而內(nèi)部未被氧化的多巴胺存在物理自聚合的可能。

圖7 直接氧化交聯(lián)聚合生成PDA的反應(yīng)過程[46-48]

研究發(fā)現(xiàn)，海洋貽貝足腺分泌的粘附蛋白具有超強的粘附性能，這些粘附蛋白中的主要物質(zhì)為DOPA和部分賴氨酸殘基，DOPA中含有豐富的兒茶酚官能團，其具有極強的化學(xué)多功能性和高親和力，其粘附能力和自身的快速化學(xué)交聯(lián)固化可以實現(xiàn)在多種材料上的粘附，而多巴胺因具有DOPA中的兒茶酚官能團和賴氨酸中的端氨基，也被證明也具有較強的粘附性能[50,51]。多巴胺在堿性溶液中可以實現(xiàn)氧化自聚合，從而形成具有較強粘附性能的聚多巴胺，實現(xiàn)在鈦基底表面的粘附。其中，類似于海洋貽貝，PDA的超強粘附性能是由于含有豐富的兒茶酚官能團，其可與基底形成牢固的共價鍵或非共價鍵（氫鍵、范德華力或堆積作用力）[46,52]。

圖8 物理和化學(xué)聚合生成PDA的反應(yīng)過程[49]

圖9 多巴（DOPA）和多巴胺（Dopamine，DA）的結(jié)構(gòu)式

為更好理解表面的化學(xué)成分，對各組樣品表面的C1s峰及N1s峰進行分峰擬合處理，如圖10所示。各組均只有一個主要的C1s峰，這可以歸因于存在的C—C/C==C及C==O/O—C==O[53]。在37 ℃下，各組樣品表面醌基—C==O的峰面積由46.66%減小至16.68%后，又增大至39.29%，且峰位先減小、后增大。60 ℃下，各組樣品表面醌基—C==O的峰面積逐漸增大，由21.65%增大至25.75%和29.19%，各組峰的位置大致相同。由圖11可知，樣品表面只有一個主要的N1s峰，表面峰面積為100%的吡咯型氮，其來自于聚多巴胺的氨基[54]。有研究表明，吡咯型氮可氧化為吡啶型氮，利于表面多巴胺的—C—OH向—C==O轉(zhuǎn)變[45]。

2.3 表面潤濕性

2 μL去離子水滴在各組試樣上的圖像如圖12所示。水滴滴下后，迅速在樣品表面鋪展開。從圖12中可以看出，AE組表面的接觸角為52.1°。陽極氧化后，由于表面納米管存在毛細效應(yīng)，且表面存在豐富的羥基，接觸角降低至42.9°。水熱處理之后，各組均表現(xiàn)出良好的親水性，且隨著反應(yīng)時間的延長，接觸角逐漸降低，AL3組和AH3組的接觸角最低，分別為23.9°和22.8°。根據(jù)Wenzel模型[55]，當(dāng)將液滴滴在樣品表面時，水滴會完全滲透進樣品的微結(jié)構(gòu)中，從而導(dǎo)致樣品表面接觸角降低。同時，由于陽極氧化后形成的納米管具有毛細效應(yīng)和豐富的Ti—OH基團[35]，且水熱處理后表面聚多巴胺涂層含有豐富的酚羥基、羧酸和氨基[56-57]，使接觸角進一步降低。有研究表明，表面較好的親水性能夠促進蛋白質(zhì)和細胞的粘附，對后期的細胞增殖、分化及植入體內(nèi)后的骨整合具有促進作用[58-60]。

2.4 耐腐蝕性測試

生物醫(yī)用金屬材料植入體內(nèi)后，在使用過程中不可避免地會發(fā)生腐蝕，導(dǎo)致植入體不穩(wěn)定，甚至松動等。生物材料一旦發(fā)生腐蝕，表面的金屬離子會從表面釋放出來，造成溶骨等并發(fā)癥[61]。試驗結(jié)果如圖13所示。相比于AE組，陽極氧化和通過水熱處理添加聚多巴胺涂層后的各組的腐蝕電位逐漸增大，代表腐蝕傾向減小，表明陽極氧化和聚多巴胺涂層能夠有效阻止腐蝕離子與Ti-6Al-4V基底的接觸。其中，AL1、AL3、AH1組的腐蝕電位最大，說明其腐蝕傾向最小。除此之外，AL1、AL3、AH1組的腐蝕電流較小，說明其腐蝕效率較低，這也與之前的研究結(jié)果相一致。因此，AL1、AL3、AH1組的耐腐蝕性相比于其他各組得到了較明顯的增強，猜想可能原因是形成的涂層較均勻，對基底形成了較好的保護作用，減弱了腐蝕離子對鈦基底的侵蝕作用。

圖10 各組樣品表面C1s光譜分峰結(jié)果

圖11 各組樣品表面N1s光譜分峰結(jié)果

圖12 樣品的表面潤濕性

圖13 各組樣品在0.9% NaCl溶液中的動電位極化曲線

3 結(jié)論

1）經(jīng)過酸蝕和陽極氧化處理，在3D打印制備的鈦合金基底上成功制備了微米和亞微米級形貌，并構(gòu)建了有序排列的TiO2納米管陣列，水熱處理之后，各組表面均成功添加了聚多巴胺涂層。

2）隨著水熱處理溫度的升高和時間的延長，納米管的管徑逐漸減小，在溫度較高、時間較長時，聚多巴胺出現(xiàn)了較明顯的團聚現(xiàn)象。表面粗糙度與反應(yīng)溫度成正相關(guān)，與反應(yīng)時間成負相關(guān)。

3）表面元素分析結(jié)果表明，各組N/C值均與理論值接近，進一步證明聚多巴胺已經(jīng)成功添加在樣品表面。表面潤濕性試驗結(jié)果表明，各組均表現(xiàn)出較好的親水性。電化學(xué)腐蝕試驗結(jié)果表明，陽極氧化和聚多巴胺涂層均能夠提高樣品的耐腐蝕性。

4）在基本保留基底表面原有的微納米雙級結(jié)構(gòu)的前提下，將3D打印鈦合金植入體在37 ℃下浸入聚多巴胺溶液中24 h后獲得的樣品具有最優(yōu)的綜合性能。

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JI Zhen-bing (1998-), Male, Postgraduate, Research focus: surface engineering of biomaterials.

Effects of Hydrothermal Temperature and Time on Surface Physical and Chemical Properties of 3D Printed Ti-6Al-4V Implants

1,1,1,1,2,1

(1. a. Key Laboratory of Ministry of Education for High-efficiency and Clean Mechanical Manufacture, b. School of Mechanical Engineering, Shandong University, Jinan 250061, China; 2. a. Department of Emergency Medicine, b. Shandong University Emergency and Critical Care Clinical Medicine Research Center, Qilu Hospital of Shandong University, Jinan 250012, China)

This study aims to explore the optimal process and parameters for preparing polydopamine coating on the surface of 3D printed Ti-6Al-4V implants with micro-nano structure. 3D printing is a promising method for preparing Ti-6Al-4V implants. However, the biological inertness of 3D-printed titanium alloys limits their ability to bind to bone tissue. The micro-nano structure on the surface of titanium alloy implants can promote cell adhesion, proliferation and bone integration. In addition, polydopamine has been shown to promote cell proliferation and reduce cytotoxicity. Therefore, hydrothermal treatment was performed on the 3D printed Ti-6Al-4V implants treated by acid etching and anodic oxidation, and polydopamine was coated on the surface of samples by hydrothermal treatment. The effects of different hydrothermal treatment temperatures and time were analyzed. Moreover, the surface morphology, roughness, elemental composition, surface wettability and corrosion resistance of each sample were characterized by scanning electron microscope, three-dimensional confocal laser microscope, X-ray photoelectron spectroscopy, contact angle measurement instrument and electrochemical workstation. The results showed that a micron-scale pit structure was constructed on the surface by acid etching. Through anodic oxidation, an ordered array of TiO2nanotubes with a diameter of about 80 nm was constructed on the basis of the original micron-scale structure. Micro-nano structures were successfully prepared on the surface of the implant. With the increase of hydrothermal treatment temperature and time, the diameter of nanotubes gradually decreased from 80 nm to about 40 nm, and even blocked. The three-dimensional topography indicated that the traces of laser scanning during the printing process could be observed on the surface of samples. Through anodic oxidation, the edges and corners became smoother than the surface after acid etching. Going forward, the results of surface element analysis suggested that the N/C value of each sample was close to the theoretical value of 0.125, indicating that the hydrothermal treatment successfully coated polydopamine on the surface based on remaining the micro-nano structure. The carbon and nitrogen elements on the surface of samples after hydrothermal treatment were subjected to peak fitting processing. In addition, the carbon elements were composed of C==O/O—C==O and C—C/C==C, and the nitrogen elements were composed of pyrrolic N, further demonstrating that the hydrothermal treatment successfully added polydopamine to the sample surface. With the increase of reaction time, the surface roughness and contact angle gradually decreased, and the roughness of each group remained between 4-5 μm. The surface contact angle after acid etching was 52.1°. After anodic oxidation, the contact angle decreased to 42.9°. Through hydrothermal treatment, the contact angle was less than 35°, showing excellent hydrophilicity. Compared with the samples after acid etching and anodic oxidation, the corrosion resistance was enhanced through hydrothermal treatment. In addition, the principles of anodic oxidation and dopamine polymerization were discussed in depth. In conclusion, the reaction temperature of 37 ℃ and the reaction time of 24 hours were suitable for the deposition of polydopamine on the surface of titanium alloy implants under the premise that the original micro-nano structure was basically retained. Furthermore, the results of this study provide a reference for the optimization of process parameters of polydopamine self-polymerization on the surface of titanium alloy implants.

3D printing; titanium alloy; implant; hydrothermal treatment; micro-nano structure; polydopamine coating

TG146；R318

A

1001-3660(2022)09-0288-12

10.16490/j.cnki.issn.1001-3660.2022.09.000

2021–09–01；

2022–06–10

2021-09-01；

2022-06-10

國家自然科學(xué)基金（51975336）；山東省重點研發(fā)計劃（2020JMRH0202）；山東省新舊動能轉(zhuǎn)換重大產(chǎn)業(yè)攻關(guān)項目（2021-13）；濟寧市重點研發(fā)計劃項目（2021DZP005）；山東大學(xué)教育教學(xué)改革研究項目（2022Y133，2022Y124，2022Y312）

Fund：The National Nature Science Foundation of China (51975336); Key Research and Development Program of Shandong Province (2020JMRH0202); Major Industrial Research Projects in Shandong Province for the Conversion of Old and New Kinetic Energy (2021-13); Key Research and Development Project of Jining City (2021DZP005) and Education and Teaching Reform Research Project of Shandong University (2022Y133, 2022Y124, 2022Y312).

紀振冰（1998—），男，碩士研究生，主要研究方向為生物醫(yī)學(xué)材料表面工程。

萬熠（1977—），男，博士，教授，主要研究方向為生物材料加工制造理論與技術(shù)。

WAN Yi (1977-), Male, Doctor, Professor, Research focus: theory and technology of biomaterial processing and manufacturing.

紀振冰, 萬熠, 趙梓賀, 等.水熱溫度和時間對3D打印Ti-6Al-4V植入體表面理化性能的影響[J]. 表面技術(shù), 2022, 51(9): 288-299.

JI Zhen-bing, WAN Yi, ZHAO Zi-he, et al. Effects of Hydrothermal Temperature and Time on Surface Physical and Chemical Properties of 3D Printed Ti-6Al-4V Implants[J]. Surface Technology, 2022, 51(9): 288-299.

責(zé)任編輯：劉世忠