PDF
摘要
自润湿流体自发润湿高温端的特性在强化传热领域具有广阔的应用前景。对水基多碳链醇自润湿流体的气-液界面特性和固-液界面特性进行研究。选择随着碳原子数增加的正丁醇、正戊醇和正庚醇,制备了不同浓度的自润湿流体。并对紫铜表面进行了不同加工方式的抛光打磨来研究自润湿流体的界面特性。结果表明:随着温度升高,高碳醇水溶液的表面张力先减小后增大,呈抛物线型。并且能够显著地降低水溶液的表面张力,在20～80℃范围内,7%丁醇水溶液表面张力平均降低了58%,2%戊醇水溶液平均降低了47%,0.1%庚醇水溶液平均降低了33%。固-液界面特性研究结果表明,在丁醇浓度<5%时,接触角随粗糙度的变化规律符合Wenzel模型预期。而当丁醇浓度≥5%时,Wenzel模型不能正确反映接触角随粗糙度的变化规律,且随着浓度的增加误差越大。此外,单向打磨紫铜表面,液滴出现形变现象。表现出明显的各向异性润湿特性,导致平槽接触角小于垂槽接触角。总之,随着水基多碳链醇自润湿流体浓度的增大和碳原子数的增加,其润湿性越好。
Abstract
Self-wetting fluid spontaneously wetting high-temperature section has a wide application prospect in the field of heat transfer enhancement.The characteristics of gas-liquid interface and solid-liquid interface of water-based multi-carbon alcohol self-wetting fluid were studied.N-butanol,n-pentanol and n-heptanol with the increase of carbon atom number were selected to prepare self-wetting fluids under different concentrations.Moreover,the solid-liquid interface characteristics of self-wetting fluid were investigated using the copper surface with different polishing ways.The results showed that the surface tension of high carbon alcohol self-wetting firstly decreased and then increased with the increase of temperature,and exhibited a parabolic shape.Furthermore,the surface tension of aqueous solution was significantly reduced.Specifically,the surface tension of 7% butanol solution decreased by 58%,2% amyl alcohol solution decreased by 47%,and 0.1% heptanol solution decreased by 33% averagely in the temperature range of 20～80℃.The results also indicated that the effect of roughness on contact angle agreed well with Wenzel model within the concentration of 5%.However,Wenzel model was failed to predict the variation of contact angle with roughness as the concentration was above 5%,and the error increased with the increase of concentration.In addition,the droplets appeared deformity when the copper surface was polished unidirectionally.It showed obvious anisotropic wettability,resulting in the wettability in parallel direction was better than perpendicular direction of the groove.In conclusion,the wettability of water based multi-carbon alcohol self-wetting fluid increased with the increase of concentration and carbon atom number.
关键词
自润湿流体
/
表面张力
/
吸附特性
/
粗糙度
/
润湿性
Key words
self-wetting fluid
/
surface tension
/
adsorption characteristic
/
roughness
/
wettability
水基多碳链醇自润湿流体界面特性研究[J].
化工新型材料, 2023, 51(1): 178-184 DOI:10.19817/j.cnki.issn1006-3536.2023.01.034
[1] 刘助仁.新能源:缓解能源短缺和环境污染的新希望[J].科技与经济,2008,21(1):35-37.
[2] 李朝兴.全力打好节能降耗持久战推进节能工作再上新水平[J].资源节约与环保,2011(4):4-6.
[3] 韩冰,徐之平.强化换热的方法及新进展[J].能源研究与信息,2008,24(4):233-237.
[4] 宣益民,李强.纳米流体强化传热研究[J].工程热物理学报,2000,21(4):466-470.
[5] 胡艳鑫,黄凯鑫,陈思旭,等.自湿润流体的流动与传热特性研究进展[J].化工进展,2017,36(12):4329-4342.
[6] 林梓荣,汪双凤,张伟保,等.功能热流体强化脉动热管的热输送特性[J].化工学报,2009,60(6):1373-1379.
[7] Vochten R,Peter G.Study of the heat of reversible adsorption at the airsolution interface Ⅱ.experimental determination of the heat of reversible adsorption of some alcohols[J].Journal of Colloid and Interface Science,1973,42(2):320-327.
[8] Abe Yoshiyuki,Iwasaki Akira,Tanaka Kotaro.Microgravity experiments on phase change of self-rewetting fluids[J].Annals of the New York Academy of Sciences,2004,1027(1):269-285.
[9] Abe Yoshiyuki.Self-rewetting fluids:beneficial aqueous solutions[J].Annals of the New York Academy of Sciences,2006,1077:650-667.
[10] 庄立宇,李春曦,施智贤,等.自润湿流体液滴在倾斜不混溶液体表面上的铺展动力学研究[J].电力科学与工程,2020,36(2):55-63.
[11] Yang Yang,Zhou Leping,Du Xiaoze,et al.Fluid flow and thin-film evolution near the triple line during droplet evaporation of self-rewetting fluids[J].Langmuir:the ACS Journal of Surfaces and Colloids,2018,34(13):3853-3863.
[12] Savino R,Paola R D,Cecere A,et al.Self-rewetting heat transfer fluids and nanobrines for space heat pipes[J].Acta Astronautica,2010,67(9):1030-1037.
[13] Sitar A,Golobic I.Heat transfer enhancement of self-rewetting aqueous n-butanol solutions boiling in microchannels[J].International Journal of Heat and Mass Transfer,2015,81:198-206.
[14] 任庆,边明远,陈飞武.液体的表面吸附:表面相厚度和热效应的理论研究[J].化学通报,2019,82(3):237-242.
[15] Hu Yanxin,Liu Tengqing,Li Xuanyou,et al.Heat transfer enhancement of micro oscillating heat pipes with self-rewetting fluid[J].International Journal of Heat and Mass Transfer,2014,70:496-503.
[16] Su Xinjun,Zhang Ming,Han Wei,et al.Experimental study on the heat transfer performance of an oscillating heat pipe with self-rewetting nanofluid[J].International Journal of Heat and Mass Transfer,2016,100:378-385.
[17] Tadmor R.Approaches in wetting phenomena[J].Soft Matter,2011,7(5):1577-1580.
[18] 李文,马骁婧,徐进良,等.纳米结构及浸润性对液滴润湿行为的影响[J].物理学报,2021,70(12):300-310.
基金资助
国家自然基金(51906013);北京建筑大学金字塔人才培养工程建大英才项目(JDYC20200316)
