Jing CHANG
材料科学技术（英）
Chitin and chitosan films were prepared by solution casting method. Chitosan specimens used in this study were deacetylated by 56.4%, 69.2%, 85.5% and 96.3%. Their water content, protein adhesion ability, cyto-compatibility, cell adhesion ability, in vitro and vivo degradability and biocompatibility were evaluated. Results indicated that with the degree of deacetylation (DD) between 50% and 70%, the chitosan showed higher water content. The higher the DD, the stronger protein adhesion ability the chitosan had. All the films have good cytocompatibility and the films with higher DD have better cell adhesion ability. Chitin films degraded more rapidly than others, which disappeared in 2 to 4 weeks after they were implanted in subcutaneous tissue and musculature. Their inflammatory reaction became weaker as the films degraded. As the DD got higher, the films degraded slower. The films of DD 85.5% and DD 96.3% even didn0t disappeared in 12 weeks after they were implanted. Their inflammatory reaction was mild at the beginning of degradation, and became severe in 4 to 8 weeks, then weaken at last. This basic result can be very helpful for tissue engineering.
关键词:
Chitosan
,
degree
,
of
,
deacetylation
,
biodegr
Suwei YAO
,
Zhaohui ZHAO
材料科学技术（英）
The Fe3O4 films were prepared by in-situ oxidative hydrolysis on chitosan. The structures and characteristics of the prepared Fe3O4 films were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM), atom force microscopy (AFM), vibrating sample magnetometry (VSM) and thermogravimetric-differential thermal analysis (TG-DTA). The results show that, (1) the as-synthesized Fe3O4 films are pure Fe3O4 with cubic inverse spinel structure; (2) the network structured film can be obtained at lower temperature, and the compact particle film at higher temperature; (3) the prepared Fe3O4 films are super-paramagnetic, and the saturation magnetization is improved with increasing the reaction temperature, which is 49.03 emu/g at 80℃; (4) the temperature of phase transformation from F Fe3O4 to α-Fe2O3 is about 495℃. Besides, the formation mechanism of Fe3O4 film was also proposed.
关键词:
Fe3O4 film
,
film
,
In-situ
,
Oxidative
,
hydrolysis
李浩
,
王征科
,
胡巧玲
材料科学与工程学报
通常在N-琥珀酰壳聚糖的合成过程中使用大量的有毒溶剂,容易造成环境污染,并且有毒溶剂易残留在产物中,限制了N-琥珀酰壳聚糖在生物医学领域的应用。本研究采用一种安全、环保的合成方法,以无水乙醇为溶剂,通过控制反应时间,合成了一系列不同取代度的N-琥珀酰壳聚糖,测定了产物的取代度,分子量及其分布,并用FTIR对其进行结构分析。采用粉末X-射线衍射、TG对其结晶性能和热稳定性进行分析,并对其水溶性和生物相容性进行了探讨。当反应时间为15 h时,所得产物的取代度最高,分子量最大,分子量分布最窄;N-琥珀酰壳聚糖的结晶性和热稳定性均弱于壳聚糖,改性的壳聚糖具有良好的水溶性。动物皮下植入实验表明,以无水乙醇为溶剂合成的N-琥珀酰壳聚糖具有良好的生物相容性,有望在生物医用材料方面得到广泛应用。
关键词:
壳聚糖
,
N-琥珀酰化
,
取代度
,
水溶性
李晓波
,
姜小莹
新型炭材料
将多壁碳纳米管(MWCNT)置于混酸(硝酸∶硫酸=1∶3)中,利用超声波振荡截短碳纳米管、并使其与羧基链接,而后基于阳离子聚合电解质壳聚糖(CS)和阴离子短切碳纳米管之间的静电作用,在玻璃衬底上通过层层的模式均匀稳定地自组装形成复合壳聚糖多层膜.UV-vis 光谱显示:组装过程呈现均匀而连续的生长.AFM和SEM观察表明:CS/MWCNT多层膜具有良好的光学特性,在生物传感器方面具有潜在的应用前景.
关键词:
多壁碳纳米管
,
层层自组装
,
壳聚糖
,
生物传感器
