Convert Word, Excel and PPT to PDF

Hi, 

Below is my code, which is generating the PDF file inside the document library but it is getting corrupted, any idea what am i doing wrong?

  var list = clientContext.Web.Lists.GetByTitle(listTitle);
                clientContext.Load(list.RootFolder);
                clientContext.ExecuteQuery();

                CamlQuery c = CamlQuery.CreateAllItemsQuery();
                ListItem lstitm = list.GetItemById(10);

                Microsoft.SharePoint.Client.File spFile = lstitm.File;
                clientContext.Load(spFile);
                Microsoft.SharePoint.Client.ClientResult<System.IO.Stream> bin = spFile.OpenBinaryStream();
                clientContext.ExecuteQuery();


                var fileCreationInformation = new FileCreationInformation();
                byte[] blob = null;

                byte[] buffer = new byte[16 * 1024];
                using (MemoryStream ms = new MemoryStream())
                {
                    int read;
                    while ((read = bin.Value.Read(buffer, 0, buffer.Length)) > 0)
                    {
                        ms.Write(buffer, 0, read);
                    }
                    blob = ms.ToArray();
                }

 fileCreationInformation.Content = blob; //bytes;
                fileCreationInformation.Overwrite = true;
                fileCreationInformation.Url = url + "/" + "Shared%20Documents" + "/Payslip_New.pdf";
                list.RootFolder.Files.Add(fileCreationInformation);
                clientContext.ExecuteQuery();

Thanks, Parth