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以玻璃纤维网为载体,采用溶胶-凝胶法,以Fe3+对TiO2催化剂实施掺杂,经胶液配制、膜的涂覆与焙烧等工序,制备改性TiO2催化膜。通过正交实验,考察了Fe/Ti质量比、涂覆次数、升温程序等因素对改性后的TiO2薄膜光催化降解苯酚性能的影响。在选定各因素各水平下,对TiO2催化膜的影响因素主次顺序为:Fe/Ti质量比>焙烧温度>涂覆次数。最优条件为:Fe/Ti质量比=0.01%;焙烧温度=600℃;涂覆次数=3次。X射线衍射(XRD)分析表明,在最佳条件下制备的改性TiO2为锐钛矿型,平均粒径为14.5nm。 相似文献
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《林业工程学报》2017,(4)
为改善竹材的防霉性能,采用低温水热法,以硝酸锌和六亚甲基四胺为原料,在竹材表面制备ZnO纳米晶层。通过扫描电镜观察了试样表面的微观形貌,并结合X射线能谱仪研究了试样表面的元素状态,还通过X射线衍射仪研究了试样的结晶形态,以及采用热失重检测仪分析了试样的热降解过程,最后测试了ZnO负载前后竹材的防霉性能。试验结果表明,低温水热法可以成功制备纤锌矿ZnO纳米晶体,并使其紧密负载在竹材表面。室内防霉试验结果表明,ZnO负载的竹材对黑曲霉和青霉具有明显的防护作用,但对木霉的防护作用不明显。室外防霉试验结果表明,与竹材素材相比,ZnO负载的竹材具有较好的防霉效果,可以使霉菌推迟2个月出现。 相似文献
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Fe3+/TiO2改性竹炭催化降解甲醛 总被引:1,自引:0,他引:1
以竹炭为载体,采用溶胶-凝胶法制备TiO2溶胶,并掺杂Fe3+,经浸渍过滤和高温焙烧制备Fe3+/TiO2改性竹炭,并用SEM和XRD进行表征.采用单因素和正交组合试验探究焙烧温度、Fe3+掺杂量、负载层数三因子对改性竹炭去除甲醛效果的影响,从而确定制备Fe3 +/TiO2改性竹炭的最优工艺.从SEM和XRD图谱表征可知,竹炭、TiO2溶胶和Fe3+三者之间能够较好地复合在一起.三因子中焙烧温度因子最为显著,其次是负载层数和Fe3+掺杂量.制备Fe3+/TiO2改性竹炭最佳工艺参数为焙烧温度450℃、负载层数2层、Fe3+掺杂量1%,其对甲醛的去除率达到61%,均高于单一竹炭或TiO2/竹炭复合对甲醛的去除率,表明三者复合具有协同促进作用. 相似文献
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活性炭比表面积、孔径对TiO_2/AC光催化活性的影响 总被引:1,自引:0,他引:1
以不同孔径和比表面积的系列活性炭(AC)为载体,通过溶胶-凝胶法制备得到TiO2/AC负载型光催化剂。利用氮气吸附、X射线衍射(XRD)、扫描电镜(SEM)对复合催化剂进行表征,并对其进行动态甲苯光降解研究。结果表明:比表面积大、大中孔道丰富的活性炭更适合于负载TiO2制备TiO2/AC复合光催化剂,并且具有更好的光催化活性和延长催化剂的失活时间,对甲苯最大降解率可达97%,失活时间可达11 h,适宜的填充量有利于提高光降解效果。 相似文献
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为增强竹材的防霉性能,以毛竹作为研究材料,先对竹材进行超声预处理,制备了抗菌石蜡乳液对竹材进行浸渍改性处理,并对改性后竹材的含水率、吸水率、防水效率和防霉性能进行了测试。选用天然植物中的2-羟基-1,4萘醌作为防霉剂,选用司班80(Span80)和吐温80(Tween80)作为58号食品级石蜡的复配乳化剂,考虑了亲水亲油平衡(HLB)值对石蜡乳化的影响,制得稳定的抗菌石蜡乳液。利用抗菌石蜡乳液对超声处理后的竹片进行浸渍处理,采用L9(33)正交试验设计,以石蜡乳液固含量、干燥温度和干燥时间为因子,以含水率和浸泡768 h后的防水效率为测试指标。结果表明,当Span80和Tween80的质量比为2∶3、HLB值为10.72时,石蜡乳液的稳定性最好。对改性后竹材含水率的影响从大到小依次是石蜡乳液固含量、干燥温度、干燥时间。当石蜡乳液固含量为5%、干燥温度为70℃、干燥时间为1.5 h时,试件含水率最低为4.11%。浸泡768 h后对竹材防水效率影响从大到小依次是干燥温度、石蜡乳液固含量、干燥时间;当石蜡乳液固含量为15%、干燥温度为40℃、干燥时间为1.5 h时,试件防水效率最高为32.15%。超声处理并不能有效阻止竹材的霉变,超声联合抗菌石蜡乳液改性后的竹材防霉性能有明显提高,改性竹材在28 d霉变试验后表面无菌丝、霉点。 相似文献
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杉木负载二氧化钛薄膜的抗菌性能 总被引:2,自引:0,他引:2
采用微波辅助液相沉积法(MWLPD)制备二氧化钛(TiO2)薄膜,并将此TiO2薄膜负载于杉木表面。微生物抗菌测试结果证明,负载TiO2薄膜的杉木,在一年内具有显著而广谱、稳定而持久的抗菌性能,而且其抗菌性能受光源和温度的影响。 相似文献
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为提高TiO2的回收性能,促进农林废弃物的资源化利用,以核桃壳为炭源,采用溶胶 凝胶法制备TiO2/核桃壳炭复合材料。通过傅里叶红外光谱、X射线衍射、比表面积和电镜扫描等手段对复合材料的化学和晶相结构、比表面积和微观形貌进行表征,并测试其对苯酚的吸附 光催化性能。物相表征结果显示,TiO2/核桃壳炭(400℃,2 h)中TiO2以锐钛矿相颗粒分散在核桃壳炭表面,炭的固载提高了TiO2的分散性能,使其晶粒尺寸由15.7 nm降低至11.6 nm,增强了可见光吸收能力。活性分析结果表明:当TiO2含量为80%,催化剂用量为2 g/L,苯酚初始质量浓度为10 mg/L,紫外光照射240 min时,TiO2/核桃壳炭(400℃,2 h)对苯酚的降解率为97.7%,化学需氧量降解率为92.36%,优于TiO2(分别为71.55%和63.34%)和商业购买的平均粒径为25 nm的锐钛矿晶和金红石晶混合相的TiO2(降解率88.56%),且几乎完全矿化,符合一级反应动力学方程。TiO2和TiO2/核桃壳炭光催化降解苯酚的主要活性中心分别为·OH和·O-2,核桃壳炭的负载提高了TiO2吸附 光催化苯酚性能和回收效率。 相似文献
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抗菌型饰面人造板的研究 总被引:6,自引:0,他引:6
研究纳米二氧化钛(TiO2)浆料以及以纳米TiO2浆料为抗菌剂的饰面人造板的制备工艺,检测在三聚氰胺甲醛树脂(MU)中添加纳米TiO2浆料制成的饰面人造板的抗菌与物理力学性能.结果表明:以聚丙烯酰胺为分散剂,聚乙二醇和辛基酚聚氧乙烯醚为润湿剂,聚乙烯吡咯烷酮(PVP)为稳定保护胶,在高速搅拌下制成的纳米TiO2浆料,在透射电镜下观察发现纳米TiO2颗粒分布均匀,具有良好的分散性,浆料经热水浴处理,TiO2基本未出现团聚,具有较好的贮存稳定性;在MU中添加纳米TiO2浆料调制的胶粘剂,其相容性好,且不影响其胶合性能;加入纳米TiO2的浸渍纸和浸渍单板具有明显的抗菌性,当MU胶粘剂中TiO2加入量为1%时,饰面人造板具有较好的抑菌效果,它对金黄色葡萄球菌和大肠杆菌均有良好的抑制作用. 相似文献
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Heshuai Cui Yu Zheng Jianfeng Ma Shumin Yang Genlin Tian Lili Shang Xing’e Liu 《Journal of Wood Science》2017,63(1):95-103
Rattan-based silicon carbide (R-SiC) ceramics, R-SiCSiO2 and R-SiCSi, were successfully prepared from silica (SiO2) sol and silicon (Si) powder, respectively. The rattan powder was impregnated, respectively, with SiO2 sol at ambient temperature and liquid melt-Si at high temperature. This was followed by one-step direct pyrolysis at 1500 °C under an argon (Ar) atmosphere. The final SiC samples were analyzed using mass analysis, X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), energy dispersive X-ray analysis (EDAX), and nitrogen (N2) physisorption techniques. Experimental results showed that the mass residual of R-SiCSi (42.56 wt%) was almost equal to R-SiCSiO2 (42.45 wt%). However, R-SiCSiO2 had a higher yield of SiC, a higher specific surface area and a more intact porous morphology preserved from the rattan biomass. In addition, some rod-like SiC whiskers and tablet-like SiC particles were found in R-SiCSiO2. By comparison, R-SiCSi had a large amount of unreacted Si, as well as certain amount of SiC and unreacted C. Thus, it can be concluded that SiO2 sols are more appropriate for use in preparation of SiC from rattan, whatever the porous microstructure, yield, and purity of SiC. 相似文献
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Falcataria moluccana or sengon is one of the fast-growing wood species widely grown in Indonesia.However,its wood is low quality with low density,and poor strength,durability,and dimensional stability.This study determined the effects of impregnation with monoethylene glycol(MEG)and nano-SiO2 on the characteristics of sengon wood,including its dimensional stability and density.Impregnation with MEG and nano-SiO2 had a significant effects on dimensional stability in terms of the weight percent gain,anti-swelling efficiency,water uptake,bulking effect,and density.The impregnated wood was examined by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and X-ray diffraction.The results show that MEG and nano-SiO2 were distributed homogeneously into cell walls of wood treated with 0.5%MEGSiO2. 相似文献
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Two new isocoumarins (1 and 2), a new alkaloid (3), and a known N-acetyldopamine dimer (4) were isolated from the ethyl acetate extract of Chinese insect medicine Eupolyphaga sinensis. Their structures were elucidated on the basis of detailed spectroscopic investigations, such as 1D- and 2D NMR spectroscopy, as well as by means of HR-MS. The structure of 1 was firmly confirmed by X-ray crystallography, and the absolute configuration was revealed by experimental and computational optical rotation analyses. Cytotoxicities of 1-4 were measured in vitro against 10 selected cancer cell lines. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):473-480
As the sawmill industry strives towards customer orientation, the need for sorting of logs according to quality has been recognized, and automatic sorting based on measurements by three-dimensional (3D) optical log scanners has been implemented at sawmills. There is even a small number of sawmills using the X-ray log scanner for automatic log-sorting. At the log-sorting stage, the potential of the raw material to fulfil the needs has already been reduced by the decisions taken when the trees were bucked (cross-cut) into logs. Thus, the application of predictions of the boards’ properties at the bucking stage is desirable. This study investigates the possibility of predicting board values from logs based on 3D scanning alone and 3D scanning in combination with X-ray scanning of stems. This study is based on 628 logs scanned by computed tomography that make up the Swedish Pine Stem Bank. Simulated sawing of the logs gave product values for each log. Prediction models on product value were adapted using partial least squares regression and x-variables derived from the properties of the logs and their original stems, measurable with a 3D log scanner and the X-ray LogScanner. The results were promising. Using a 3D scanner alone, R 2 was 0.68, and using a 3D scanner in combination with an X-ray LogScanner, R 2 was 0.72. 相似文献