Crystallization time in ZnO: the role of surface OH groups in its photoactivity

2020 ◽  
Vol 44 (42) ◽  
pp. 18216-18224
Author(s):  
Jéssica C. de Almeida ◽  
Mateus T. Corrêa ◽  
Rafaella H. Koga ◽  
Douglas M. S. Del Duque ◽  
Osmando F. Lopes ◽  
...  
Keyword(s):  
Critical Role ◽  
Surface Modifications ◽  
Crystallization Time ◽  
Hydroxyl Groups ◽  
Surface Groups ◽  
Oh Groups

The crystallization time and surface modifications concerning the hydroxyl groups on the ZnO catalyst were studied and the results suggest that there is a balance between the surface groups and morphology playing a critical role in its photoactivity.

scholarly journals The Role of Carboxyl and Hydroxyl Groups of Humic Acid in Removing AuCl4- from Aqueous Solution

2017 ◽  
Vol 17 (1) ◽  
pp. 95 ◽  
Author(s):  
Sri Sudiono ◽  
Mustika Yuniarti ◽  
Dwi Siswanta ◽  
Eko Sri Kunarti ◽  
Triyono Triyono ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Peat Soil ◽  
Sharp Decrease ◽  
Hydroxyl Groups ◽  
Mixed Solution ◽  
Oh Groups ◽  
Characterization Result ◽  
Ft Ir

Humic acid (HA) extracted from peat soil according to the recommended procedure of the International Humic Substances Society (IHSS) has been tested to remove AuCl4- from aqueous solution. The removal was optimum at pH 2.0 and it was mainly dictated by attachment through hydrogen bonding to unionized carboxyl (–COOH) groups and reduction by the action of the hydroxyl (–OH) groups to gold (Au) metal. The removal of AuCl4- improved after HA was purified through repeated immersion and shaking in a mixed solution containing 0.1 M HCl and 0.3 M HF. When the purification led to the sharp decrease in ash content from 39.34 to 0.85% (w/w) and significant increase in both the –COOH and –OH contents from 3240 to 3487 mmol/kg and from 4260 to 4620 mmol/kg, respectively; the removal of AuCl4- improved from 0.105 to 0.133 mmol/g. This improvement of AuCl4- removal by the purified HA was accompanied by higher ability in reduction to Au metal. The attached AuCl4- on –COOH groups of both crude and purified HAs was qualitatively observed by the characterization result of FT-IR spectroscopy, while the presence of Au metal on the surface of those HAs was verified by the characterization result of XRD.

scholarly journals Thermal modification of wood—a review: chemical changes and hygroscopicity

2021 ◽  
Author(s):  
Callum Hill ◽  
Michael Altgen ◽  
Lauri Rautkari
Keyword(s):  
Cell Wall ◽  
Moisture Content ◽  
Dimensional Stability ◽  
Thermal Modification ◽  
Hydroxyl Groups ◽  
Water Leaching ◽  
Topic Area ◽  
Sorption Behaviour ◽  
Oh Groups

Abstract Thermal modification is a well-established commercial technology for improving the dimensional stability and durability of timber. Numerous reviews of thermally modified timber (TMT) are to be found in the scientific literature, but until now a review of the influence of cell wall moisture content during the modification process on the properties of TMT has been lacking. This paper reviews the current state of knowledge regarding the hygroscopic and dimensional behaviour of TMT modified under dry (cell wall at nearly zero moisture content) and wet (cell wall contains moisture) conditions. After an overview of the topic area, the review explores the literature on the thermal degradation of the polysaccharidic and lignin components of the cell wall, as well as the role of extractives. The properties of TMT modified under wet and dry conditions are compared including mass loss, hygroscopic behaviour and dimensional stability. The role of hydroxyl groups in determining the hygroscopicity is discussed, as well as the importance of considering the mobility of the cell wall polymers and crosslinking when interpreting sorption behaviour. TMT produced under wet processing conditions exhibits behaviour that changes when the wood is subjected to water leaching post-treatment, which includes further weight loss, changes in sorption behaviour and dimensional stability, but without any further change in accessible hydroxyl (OH) content. This raises serious questions regarding the role that OH groups play in sorption behaviour. Graphical abstract

scholarly journals The critical role of hydroxyl groups in water vapor sensing of graphene oxide

2019 ◽  
Vol 1 (4) ◽  
pp. 1319-1330 ◽  
Author(s):  
Qawareer Fatima ◽  
Azhar Ali Haidry ◽  
Zhengjun Yao ◽  
Yue He ◽  
Zhong Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Water Vapor ◽  
Critical Role ◽  
Sensor Response ◽  
Hydroxyl Groups ◽  
Humidity Sensors ◽  
Vapor Sensing ◽  
Conceptual Advance

The present study provides a significant conceptual advance in graphene oxide based humidity sensors. It is found that sensor response is directly dependent on the amount of OH− groups. The proposed strategy to control OH− in this report can make significant impact on the development of future smart GO-based humidity sensors and should be applicable to other gases.

Nonisocyanate Thermoplastic Polyhydroxyurethane Elastomers via Cyclic Carbonate Aminolysis: Critical Role of Hydroxyl Groups in Controlling Nanophase Separation

2016 ◽  
Vol 5 (4) ◽  
pp. 424-429 ◽  
Author(s):  
Emily K. Leitsch ◽  
Goliath Beniah ◽  
Kun Liu ◽  
Tian Lan ◽  
William H. Heath ◽  
...  
Keyword(s):  
Critical Role ◽  
Cyclic Carbonate ◽  
Hydroxyl Groups ◽  
Nanophase Separation

The Role of the SLP in Autism Spectrum Disorder Screening and Assessment

2008 ◽  
Vol 15 (2) ◽  
pp. 50-59 ◽  
Author(s):  
Amy Philofsky
Keyword(s):  
Language Development ◽  
Critical Role ◽  
Children With Autism ◽  
Autism Spectrum ◽  
Children With Asd ◽  
Prevalence Estimates ◽  
Notable Increase ◽  
Screening Assessment ◽  
Critical Components

AbstractRecent prevalence estimates for autism have been alarming as a function of the notable increase. Speech-language pathologists play a critical role in screening, assessment and intervention for children with autism. This article reviews signs that may be indicative of autism at different stages of language development, and discusses the importance of several psychometric properties—sensitivity and specificity—in utilizing screening measures for children with autism. Critical components of assessment for children with autism are reviewed. This article concludes with examples of intervention targets for children with ASD at various levels of language development.

A critical role of iNOS-derived Nitric Oxide (NO) and progesterone in implantation

1998 ◽  
Vol 5 (1) ◽  
pp. 115A-115A
Author(s):  
K CHWALISZ ◽  
E WINTERHAGER ◽  
T THIENEL ◽  
R GARFIELD
Keyword(s):  
Nitric Oxide ◽  
Critical Role
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