殼聚糖-聚乙烯醇復(fù)合水凝膠溶脹度及其生物相容性 化工與環(huán)境工程----- 外文翻譯.doc
約5頁(yè)DOC格式手機(jī)打開(kāi)展開(kāi)
殼聚糖-聚乙烯醇復(fù)合水凝膠溶脹度及其生物相容性 化工與環(huán)境工程----- 外文翻譯,2.2.1 chitosan and pva solution preparationbriefly, pva hydrogels were prepared by fully dissolving 5.0g of polymer powder without further purificat...
![](http://img.queshao.com/images/pcgzh.gif)
![](http://preview.queshao.com/tobuy/212120.gif)
內(nèi)容介紹
此文檔由會(huì)員 wanli1988go 發(fā)布2.2.1 Chitosan and PVA solution preparation
Briefly, PVA hydrogels were prepared by fully dissolving 5.0g of polymer powder without further purification in 100 ml of Milli-Q water, under magnetic stirring, at temperature of 75 ± 2℃ (solution A), as previously reported by our group [7–9]. PVA 5% solution was let to cool down to room temperature and the pH was corrected to (2.00 ± 0.05) with 1.0 M HCl (Sigma). Chitosan hydrogels (Chi) were produced in a similar procedure by fully dissolving 2.5g in 250.0ml of Milli-Q water with 2% of CH3COOH (Sigma),under magnetic stirring for 48 h (solution B).
2.2.2 Chitosan, PVA and blends films preparation
Different quantities of PVA (solution A) were added into the 1.0% chitosan solution (solution B) to obtain chitosan/PVA mass ratios of (0:1), (1:3), (1:1), (3:1), and (1:0) and pH was corrected to (4.00 ± 0.05) with 1.0 M NaOH solution. The mixture was kept under stirring for 5 min until the PVA and chitosan completely formed a clear solution. Then, the crosslinker reagent (GA) was slowly added under constant stirring. The final concentration of GA in the gel solution precursors was 1% and 5% (wt%). Further in thesequence, the solution was poured into plastic moulds and let drying for 72–120 h at room temperature, and finally dried at 40℃ for 24 h (constant weight). Chitosan/PVA samples chemically crosslinked were identified by (X:Y:Z) that is, X as chitosan content, Y as PVA content, and Z as GA (wt%). For instance, sample identified as Chi/PVA/GA (1:3:1) represents the following proportion of reagents: 25% chitosan, 75% PVA and crosslinked with 1.0% GA (wt%). The dried gel was stored in a desiccator before all sub-sequent characterization procedures.
2.2.1殼聚糖溶液和PVA溶液制備
首先,聚乙烯醇水凝膠的制備,是先稱5.0g聚乙烯醇粉末使其在100ml純凈水中進(jìn)一步完全溶解,同時(shí)在電磁攪拌下,溫度控制75±2℃(溶液A),就像我們團(tuán)隊(duì)之前的報(bào)道所示。[7-9]。5%的聚乙烯醇完全溶解后,讓其冷卻到室溫和用1.0 M鹽酸( )把pH值控制在(2.00±0.05)。殼聚糖水凝膠(殼聚糖)制備采用相似的步驟,稱2.5g殼聚糖在250ml 2%的醋酸溶液( )中,電磁攪拌48小時(shí)(溶液B)。
2.2.2殼聚糖和聚乙烯醇復(fù)合水凝膠制備
用不同量的聚乙烯醇溶液(溶液A)加入到1.0%的殼聚糖溶液(溶液B)獲得以下幾種殼聚糖/聚乙烯醇水凝膠,分別質(zhì)量比為(0:1),(1:3 ),(1:1),(3:1)和(1:0)和用1.0M氫氧化鈉溶液把pH值調(diào)節(jié)在(4.00±0.05)。將該混合物繼續(xù)攪拌5分鐘,直到聚乙烯醇和殼聚糖完全形成了清澈溶液。然后,緩慢加入交聯(lián)劑(戊二醛),并不斷攪拌。在溶液凝膠初期,戊二醛的最后濃度為1%和5%(質(zhì)量分?jǐn)?shù)%)。隨著進(jìn)一步反應(yīng),溶液不斷塑化,接著在室溫下其讓干燥72至120 h,最后在40℃干燥24小時(shí)(恒重)。殼聚糖-聚乙烯醇復(fù)合水凝膠樣品的化學(xué)交聯(lián)反應(yīng)產(chǎn)生凹痕已確定為(X: Y: Z)三種因素,X為殼聚糖的含量,Y為聚乙烯醇的含量,Z為戊二醛(質(zhì)量分?jǐn)?shù)%)。例如,樣品組成確定為殼聚糖/聚乙烯醇/戊二醛=(1:3:1),則:25%的殼聚糖,75%聚乙烯醇和1.0%(質(zhì)量分?jǐn)?shù)%)戊二醛。干凝膠儲(chǔ)存在干燥器之前,要記錄樣品每一個(gè)特征。
TA們正在看...
- 銷(xiāo)售工作計(jì)劃書(shū)結(jié)尾.docx
- 銷(xiāo)售市場(chǎng)年終計(jì)劃怎么寫(xiě).docx
- 銷(xiāo)售年會(huì)發(fā)言稿怎么寫(xiě).docx
- 銷(xiāo)售年會(huì)發(fā)言稿范文三篇.docx
- 銷(xiāo)售年工作總結(jié)與計(jì)劃800字.docx
- 銷(xiāo)售年工作總結(jié)與計(jì)劃ppt.docx
- 銷(xiāo)售年工作總結(jié)和計(jì)劃范例.docx
- 銷(xiāo)售年終工作思路計(jì)劃.docx
- 銷(xiāo)售年終工作總結(jié)與計(jì)劃開(kāi)頭語(yǔ).docx
- 銷(xiāo)售年終工作總結(jié)與計(jì)劃報(bào)告.docx