2D Solid-State HETCOR 1H-13C NMR Experiments with Variable Cross Polarization Times as a Tool for a Better Understanding of the Chemistry of Cellulose-Based Pyrochars—A Tutorial

نویسندگان

چکیده

The chemistry and nature of biochars are still far from being well understood. In the present work, solid-state 2D HETCOR 1H-13C NMR spectroscopy is introduced for an improved characterization aromatic network in biochars. To that end, a pyrochar obtained pyrolysis cellulose at 350 °C 1 h was used as example. Variation contact time during cross polarization 50 µs, to 200 µs 1000 gave information about protonation degree different C groups their interactions. We demonstrated carbohydrates did not survive conditions. Therefore, O-alkyl assigned ethers. Phenols were identified higher extent suggesting furan benzofuran-type units determine O-functionality domains. latter directly connected alkyl chains. Those features expected affect chemical but also physical properties biochar. Based on our results, we developed new concept describing studied cellulose-based pyrochars. contrasts common views biochar, possibly because temperatures > required achieving advanced condensation

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Quantitative 13C MultiCP solid-state NMR as a tool for evaluation of cellulose crystallinity index measured directly inside sugarcane biomass

BACKGROUND The crystallinity index (CI) is often associated with changes in cellulose structure after biological and physicochemical pretreatments. While some results obtained with lignocellulosic biomass demonstrate a progressive increase in the CI as a function of pretreatments, it is also shown that the CI can significantly vary depending on the choice of the measurement method. Besides, the...

متن کامل

the effectiveness of strategy-based instruction in teaching english as a second or foreign language: a meta-analysis of experimental studies

a large number of single research studies on the effects of strategy-based instruction (sbi) in teaching english as a foreign or second language has been conducted so far. however, the lack of a comprehensive meta-analysis targeting the effectiveness of english language sbi is observed. moreover, the findings of experimental studies regarding the context of the english language, proficiency lev...

investigating the feasibility of a proposed model for geometric design of deployable arch structures

deployable scissor type structures are composed of the so-called scissor-like elements (sles), which are connected to each other at an intermediate point through a pivotal connection and allow them to be folded into a compact bundle for storage or transport. several sles are connected to each other in order to form units with regular polygonal plan views. the sides and radii of the polygons are...

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Applied sciences

سال: 2021

ISSN: ['2076-3417']

DOI: https://doi.org/10.3390/app11188569