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Questions related from Chao Wang
Hi, guys. Recently, I was doing research on mesoporous silica. I used the traditional ingredient to synthesis it, namely TEOS, CTAB, ammounia aqueous, ethanol and water. To my surprise, when I...
07 July 2019 7,113 4 View
I've been doing adsorption of heavy metals using nanoparticles as adsorbant. Typically, there are two ways of adding the adsorbant(i.e. the nanoparticles). One is to add the suspension of...
09 September 2017 9,155 8 View
When we make active carbon with calcination method, we usually make the temperature as high as 600 degree C or higher. The carbon backbone structure maintained as a result. But why doesn't the C-C...
07 July 2017 926 3 View
My system is polymer aggregates formed by two types of polymer chains via hydrogen-bonding in aqueous solution, which is a phase-separated system. I want to figure out the Rg of the aggregates in...
10 October 2016 7,504 3 View
I've been doing hydrolyze a PtBA polymer into PAA. I found there are many researchers doing this with TFA in DCM solution of PtBA. However, I tried this method for several times, the solution of...
09 September 2016 1,209 3 View
These two decades, the synthetic strategy of cyclic polymer is heated studied. However, the applications of such polymer are not as much as people expect. Especially these years, the investigation...
08 August 2016 3,007 3 View
I have been doing an end-group reaction of polymer. The former step of this is a substitution reaction using NaH(I used it directly without removal of the mineral oil). However, after many times...
08 August 2016 594 2 View
I wanted to determine the Mw and Rg of PNIPAAM with static light scattering(SLS) in aqueous solution.The Mn of PNIPAAM is about 10000g/mol according to HNMR and GPC results. But somebody says...
05 May 2016 6,902 4 View
I ve been doing some experiment on PNIPAAM dilute aqueous solution. However, when measuring the size of each polymer molecue, the DLS result always shows two peaks, namely a fast mode and a slow...
02 February 2016 6,134 6 View
As we know, some certain pairs of polymers can form interpolymer complexes in solution which can be detected by scattering or other method. However, in preparing such samples(or change pH...
12 December 2015 3,086 1 View
I have been doing some research on forming micelles that are formed by block copolymers. I want to know that if the concentration of the system get lower than cmc, will the micelles break up and...
11 November 2015 3,701 3 View
Hi everyone. I have been doing some research on polymer complexes. I saw many of papers measured the Rh of the complexes with DLS and Rg with SLS. But the problem concerned me is that when we...
07 July 2015 9,413 5 View
I've been synthesizing PNIPAAM these days.However, when I characterized it by GPC, whose eluent is THF, I found the retention time was kind of wired(which is extremely long) and the shape of the...
02 February 2015 900 9 View
I wanted to synthesize some polymer of a particular Mn, but when I characterized it with GPC, I found there were two peaks which overlapped with each other. I heard there is a method called...
01 January 2015 8,583 6 View
I wanted to carry out a polymerization reaction using radical mechanism, so I wanted to recrystallize my initiator AIBN. Can anyone help me with it? Thank you.
09 September 2014 4,834 6 View
When washing Cu-salt after a PEG-modification reaction, some papers report passing a basic alumina column would work. But when I tried it, I found most of the PEG product adsorbed on the column. I...
08 August 2014 4,842 3 View
One of the reactions in my synthesis process is to oxidate a methyl group at benzyl position into an aldehyde group using K2S2O8 as oxidant and CuSO4 as catalyst. I want to know what the...
07 July 2014 6,491 1 View
I've been making star shaped polymers, but the core molecule which is poly-alcohol or poly-carboxylic acid does not dissolve in solvents like THF, DMF, or CH2Cl2. I cannot modify them and do next...
06 June 2014 4,869 5 View
I want to know if glass substrate can be used to get clear photographs in SEM. I know silicon has better conductivity, but my sample was prepared on a glass substrate. Thank you.
05 May 2014 9,793 22 View
I am about to carry on a click reaction. I heard of that NaN3 is a dangerous compound which is easily explodable, and HN3 is as poisonous as HCN! What details should I pay attention to? Can you...
05 May 2014 5,553 5 View
I want to know the dispersion of the nanoparticles mixed in the polymer membranes, how could I do with it? I tried to paste the micrometer-scale-thick membrane on the electric-conductive tape to...
05 May 2014 9,091 11 View
I need to prepare a 2% PEO (Mw=100000) aqueous solution. I've tried to heat it to 45℃, but there were still some white cotton-like precipitate. I used to make PEG Mw-8000 aqueous solution, which...
04 April 2014 2,977 6 View
I am doing molecular-imprinted experiments, in UV-vis measurement, my sample solvent is methanol and acetone(9:1). I have scanned the baseline, but when I scanned the sample, it showed a negative...
02 February 2014 3,279 2 View
In measuring zeta potential of nanoparticle SiO2@APTES--Br, the value of zeta potential fluctuate from -3mV to -8mV in three times of measuring. Each measuring lasts 2min. Is it normal? Thanks!
12 December 2013 10,031 5 View
I want to graft poly(1-octadecane) onto TiO2 nanoparticle and wonder if 1-octadecane can be polymerized. Can anyone give me some advice?
12 December 2013 7,090 0 View
Theoretically, FT-IR, XPS, TGA can reveal a successful grafting of silicon coupling agent. However, all of these methods may show an ambiguous result,which is a bit reluctant to demonstrate an...
12 December 2013 7,593 2 View
