以木材为基材的化学镀镍

为了实现木材性能的扩展,研究了木材无钯盐活化化学镀镍和木材先化学镀铜再化学镀镍的工艺技术。实验结果表明,直接镀镍所得镀层呈黑色,无光泽,在80倍显微镜下可看到少许亮镍晶粒;先镀铜再镀镍工艺由于铜镀层疏松而无法得到良好的镍镀层,因此改善铜镀层是木材镀镍工艺的关键。     

CCA 防腐剂在木材中的固着机理

加铬砷酸铜(CCA)作为木材防腐剂在世界范围内已经广泛使用了70余年,目前在我国其仍然是主要的木材防腐剂之一.然而.CCA 中有效成分铬和砷的氧化物所具有的剧毒性,使其在使用过程中流失到外界后会对环境及生物安全造成威胁,而防腐剂中有效成分的流失在很大程度上是由于防腐处理材在使用前防腐剂的有效成分与木材成分之间的固着反应不充分而造成的.对CCA中有效成分在处理材中的固着反应过程、监测方法及反应场所等做了详细介绍,旨在为水基木材防腐剂有效成分在处理材中的固着、流失研究提供借鉴,并为CCA防腐处理材的生产提供理论指导.     

新型水基防腐剂在木材中的固着机理研究进展

对几种主要的水基木材防腐在木材中的固着机理进行了介绍。其中,在胺/氨铜防腐剂体系中,防腐剂中有效成分与木材实质间的反应主要为木质素及半纤维素中的羧基及羟基发生离子交换反应;在微化铜木材防腐剂体系(MCQ/MCA)中,防腐剂中有效成分通过高分子分散剂与木材纤维间较强的附着力固着在处理材中;而在硼类防腐剂体系中,防腐剂中有效成分的固着机理与铜比较相似,但硼酸盐无法直接固着在羧基及羟基中,因此有效成分的固着研究主要涉及以下两个方面:1)增加硼类防腐处理材的疏水性;2)与有机化学物质复合生成稳定的化合物固着在木材中。     

后干燥处理对防腐木材性能的影响初步研究

试验初步研究了后干燥处理对加铬砷酸铜(CCA-C)、季铵铜(ACQ-C和ACQ-D)三种防腐处理木材中铜的流失影响。结果表明:随着流失次数的增加,CCA-C、ACQ-C、ACQ-D三种防腐处理木材的铜流失量都呈降低趋势,最终降至非常低。随着处理温度的升高,3种防腐材的铜流失量都有所增大。CCA-C型木材防腐剂的抗流失性优于ACQ型木材防腐剂。在同等条件下,ACQ-D防腐材的铜流失率高于ACQ-C防腐材。     

浸渍药剂加速热处理对木材质量损失和耐腐性能的影响

采用主要成分为氯化锌、磷酸二氢铵及复合铜盐(硝酸铜+醋酸铜)的三种药剂对马尾松和桉树木材做浸渍处理后再进行短周期加热处理的方法,研究了处理工艺对热处理木材失重率和耐腐性能的影响。结果表明:处理木材的失重率和耐腐性能均随着处理温度升高和处理时间的延长而增大,氯化锌药剂热处理木材在较高温度下对木材的失重率影响最大,具有明显加速热处理反应的作用;但是在同样的热处理温度条件下,浸渍氯化锌和复合铜盐的热处理木材耐腐性明显优于未加药剂的热处理木材。三种药剂中,由复合铜盐浸渍处理的木材经190℃热处理后能达到强耐腐等级。     

热处理对马尾松木材霉变环境的影响

热处理作为可改善马尾松Pinus massoniana木材尺寸稳定性、耐久性和颜色等性能的技术,且因具有较好的环保性而广泛应用,同时存在易霉变等缺点。热处理过程中,木材中的糖类物质随水分的挥发而迁移或因高温受热而降解,并伴有木材pH值的变化,而木材中的各类糖分含量以及pH值是影响霉菌生长繁殖非常重要的因素。以马尾松木材为研究对象,采用纳米铜原位制备和高温热处理相结合的方法,单因素法设计实验,探讨不同热处理方法对马尾松木材中可溶性总糖、还原糖、pH值的影响。研究结果表明:热处理木材的总糖和还原糖浓度比素材高,含铜热处理材的总糖和还原糖含量比素材低,且以浓度为7.70%的含铜浸渍液处理后再在220℃/3 h条件下热处理的含铜热处理材总糖和还原糖浓度最低,分别比素材低48.7%、33.8%,比220℃/3 h获得的不含铜热处理材低538.7%、61.4%,纳米铜粒子的引入有效减少了热处理材中各糖类物质,在一定程度上降低热处理木材霉变的风险;热处理木材的酸碱度值在4.38～5.10之间,呈酸性,而含铜热处理木材的酸碱度值在6.63～7.12之间,呈弱酸或中性,可减少容易在酸性环境中生长的霉菌,同时根据不同菌种适宜生长的酸碱度值,能更有针对性的建立防霉措施,提高木材对特定菌种的防治效力。     

松香在木材防腐中的应用

从松香降低木材吸湿性、对水基木材防腐剂的固着以及抑木腐菌松香衍生物的制备3个方面讲述了松香在木材防腐中的应用现状.较高浓度的松香乳液处理对提高木材的耐腐性能有一定帮助,较低浓度的松香乳液处理就表现出对易流失的铜盐类防腐剂较好的固定作用.以松香为原料合成的松香胺类、季铵盐等衍生物能够赋予木材较好的耐腐性能,咪唑啉等其它活...     

环保防腐剂处理木材的耐腐性能研究

以马尾松为研究对象,分别采用铜唑和季铵铜(ACQ)两种环保型防腐剂处理木材,研究不同防腐剂对木材耐腐性能的影响。结果表明:两种防腐剂处理的木材耐腐等级为强耐腐,防腐效果显著;铜唑防腐剂浓度和成本较低,可推广应用于古建筑及传统民居木构件防护工程。     

铜类木材防腐剂抗流失性能的研究进展

铜类木材防腐剂是一种高效低毒型防腐剂,但抗流失性能较差。通过总结归纳木材表面处理、预处理和后处理及添加助剂改善铜类木材防腐剂抗流失性的研究进展,为铜类防腐剂的进一步研究和推广提出建议。     

含铜木材防腐剂的流失性能

依据AWPA E11-97标准,对不同配方含铜防腐剂的铜及三唑流失率进行了测定.结果表明,以氨水为配体的铜唑(CuAz)及ACQ制剂中,铜在木材中的固着率均高于乙醇胺,氨水有利于铜在木材中固着.乙醇胺为配体的CuAz及ACQ制荆中,低栽药量铜制剂的固着率均远高于高栽药量铜制剂.三唑制剂中含有铜,能降低戊唑醇的流失率,用乙醇作溶剂的戊唑醇的流失率相对较高,可达37%.     

Development of Electroless Copper and Gold Plating on Wood

The use of more and more electron products requires interior wood products to have the performance of electromagnetic shielding. One of the ways to realize it is to introduce the chemical plating which has already been developed in electron industry into wood processing. The paper clarifies the mechanism of electroless copper and gold plating and its application to wood. It emphasizes the development and technology of electroless copper and gold plating on wood. Meanwhile, it points out that it is highly feasible to take this technology into effect.     

Electromagnetic interference shielding material from electroless copper plating on birch veneer

Copper coating on birch veneer substrate was conducted by electroless deposition to prepare electromagnetic interference shielding material. In the process, Pd²⁺ ions were chemically adsorbed on the wood surface modified with chitosan. Then, they were reduced and dipped into a plating bath where copper film was successfully initiated. The coatings were characterized by SEM–EDS, XPS, and XRD. The metal deposition, surface resistivity, and electromagnetic shielding effectiveness were measured. The morphology of the coating observed by SEM is uniform, compact, and continuous. EDS, XPS, and XRD results showed that the coating consists of Cu⁰ with crystalline structure. Moreover, the copper films firmly adhere to the wood surface. Birch veneers plated with crystalline copper film exhibit high electro-conductivity with surface resistivity of 119.1?mΩ?cm^?2 and good electromagnetic shielding effectiveness of over 60?dB in frequencies ranging from 10?MHz to 1.5?GHz.     

木材炭化与炭化物利用研究进展

木材通过炭化可转化为木炭, 进一步反应可以制备隔音材料、环境净化材料、导电材料、电磁屏蔽材料以及类似陶瓷结构的仿生材料等新型生物质材料。文中从炭化的方法、机理以及产物的应用等方面对木材炭化的研究进行了综述。     

国内外木材耐光老化技术研究现状

木材在户外利用时,进行耐光老化处理可以有效提高木材制品的使用寿命。文中主要从木材涂饰处理和化学改性2个方面对木材耐光老化处理技术进行较为系统、全面的介绍,分析了无机紫外吸收剂、有机紫外吸收剂、木蜡油、化学改性及抗氧化剂等方法的优缺点。未来的耐光老化技术应主要满足以下几点:价格便宜,处理容易,低毒环保,紫外线屏蔽性能好,不损害木材表面性能及涂料涂饰性能;应主要开发多组分复配涂料以满足上述要求,克服单组份耐光老化技术的不足。     

Surface characteristics of electroless nickel plated electromagnetic shielding wood veneer

Wood is a kind of porous natural material with very poor electro-conductivity, and it has almost no function of electromagnetic shielding. The method of electroless nickel plating was used to produce wooden material with electrical and effective electromagnetic shielding properties. Ni-P alloy layer was obtained on wood surface. The surface feature of plated wood veneer was observed by SEM and the surface composition and microstructure of the layer under different conditions were investigated by EDS and XRD respectively. Meanwhile, the relevant surface resistivity and electromagnetic shielding effectiveness were measured. Correlations of the phosphorous content in the layer to the structure of Ni-P alloy, electro-conductivity and electromagnetic shielding of plated veneers were discussed. SEM photos showed that the surface of electroless nickel plated veneers were covered with Ni-P alloy layer entirely, which made wood veneers more like metal. At the same time, the results showed that with the decreasing of the phosphorous content in the layer, the microstructure of Ni-P alloy layer transformed to be microcrystalline and electro-conductivity and electromagnetic shielding effectiveness were improved. When the phosphorous content was less than 2.37wt pct in the layer, the microstructure of Ni-P alloy layer was microcrystalline structure and its sur- face resistivity and electromagnetic shielding effectiveness were nearly 0.5Ω/□ and 55-60dB respectively.     

木基电磁屏蔽(导电)功能复合材料的研究进展

介绍了电磁污染的来源、传播途径和危害，阐述了电磁屏蔽的原理及手段，并在此基础上介绍了国内外木基电磁屏蔽(导电)复合材料的研究和发展状况，提出了改善木基导电功能复合材料屏蔽效能的方法。     

电磁屏蔽木基复合材料的研究现状和发展趋势

在介绍电磁屏蔽原理的基础上,概述国内外对电磁屏蔽木基复合材料的研究状况,并展望电磁屏蔽木基复合材料的研究趋势和应用前景.     

无电解电镀法制备具有电磁屏蔽功能的木材-金属复合材料

利用无电解电镀的方法制备了导电且具有电磁屏蔽功能的木材-金属复合材料.探讨了镀液用量、施镀时间和施镀温度对复合材料的表面电阻率和电磁屏蔽效能的影响,同时利用能谱分析(EDS)、X射线衍射分析(XRD)和扫描电镜分析(SEM)方法分别测定了不同施镀温度下得到的各镀层的磷含量、微结构和表面形貌.实验结果表明,在镀液使用量为500mL,施镀时间为30min和施镀温度为62℃的最优条件下,所得镀层的导电性和电磁屏蔽效果最佳.而且发现,随着施镀温度的提高,镀层中磷含量缓慢增加.XRD分析表明不同温度所得各镀层的结构均为多晶结构,通过SEM分析,镀层均匀、连续且具有金属光泽,说明在pH值一定的条件下,施镀温度对镀层结构和表面相貌的影响很小.图7表3参11.     

杨木单板表面化学镀镀前活化工艺

化学铰铰前的活化工艺至关重要，它对化学铰铰层的性能影响很大。对杨木单板化学铰铰前的活化液种类、活化时间及活化温度对铰后杨木单板电磁蔽效果影响的研究结果表明，活化杨木单板比较理想的活化液为活化液NO．3，适宜的活化时间为6min，活化温度为室温(24℃)。最佳工艺条件下，铰后杨木单板的电磁蔽效果达到50～60dB。     

Electromagnetic shielding wood-based composite from electroless plating corrosion-resistant Ni–Cu–P coatings on Fraxinus mandshurica veneer

A novel and simple electroless Ni–Cu–P plating process was used for preparing corrosion-resistant and electromagnetic interference shielding wood-based composite. The effects of CuSO₄·5H₂O concentration, pH value in the plating solution and operation temperature on the metal deposition, surface resistivity, chemical composition, corrosion resistance and surface morphology of the composite were investigated. The surface morphologies were observed by using scanning electron microscopy and the chemical compositions were analyzed by X-ray energy dispersive spectrometer. The electromagnetic shielding effectiveness (ESE) was measured by spectrum analyzer. The corrosion resistance was evaluated by potentiodynamic corrosion measurement. The results show that metal deposition increases with pH value and temperature increase; however, it decreases with CuSO₄·5H₂O concentration increase. The corrosion resistance of the plated Ni–Cu–P coatings obviously depends on the total content of Cu and P in the coating. Higher total content of Cu and P leads to higher corrosion resistance. The optimum conditions are as follows: CuSO₄·5H₂O concentration of 1.0 g/L, pH value of 9.5, and operation temperature of 90 °C. The obtained coating contains 77.41 % Ni, 8.96 % Cu, and 13.63 % P. The wood-based composite exhibits higher corrosion resistance and ESE of around 60 dB in frequencies ranging from 9 kHz to 1.5 GHz. In this paper, a promising process for corrosion-resistant and electromagnetic shielding wood-based composites was developed.